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Logan RAE, Mäurer JB, Wapler C, Ingham VA. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) are associated with insecticide resistance in the major malaria vectors Anopheles gambiae s.l. and Anopheles funestus. Sci Rep 2024; 14:19821. [PMID: 39191827 DOI: 10.1038/s41598-024-70713-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 08/20/2024] [Indexed: 08/29/2024] Open
Abstract
Malaria remains one of the highest causes of morbidity and mortality, with 249 million cases and over 608,000 deaths in 2022. Insecticides, which target the Anopheles mosquito vector, are the primary method to control malaria. The widespread nature of resistance to the most important insecticide class, the pyrethroids, threatens the control of this disease. To reverse the stall in malaria control there is urgent need for new vector control tools, which necessitates understanding the molecular basis of pyrethroid resistance. In this study we utilised multi-omics data to identify uridine-diphosphate (UDP)-glycosyltransferases (UGTs) potentially involved in resistance across multiple Anopheles species. Phylogenetic analysis identifies sequence similarities between Anopheline UGTs and those involved in agricultural pesticide resistance to pyrethroids, pyrroles and spinosyns. Expression of five UGTs was characterised in An. gambiae and An. coluzzii to determine constitutive over-expression, induction, and tissue specificity. Furthermore, a UGT inhibitor, sulfinpyrazone, restored susceptibility to pyrethroids and DDT in An. gambiae, An. coluzzii, An. arabiensis and An. funestus, the major African malaria vectors. Taken together, this study provides clear association of UGTs with pyrethroid resistance as well as highlighting the potential use of sulfinpyrazone as a novel synergist for vector control.
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Affiliation(s)
- Rhiannon Agnes Ellis Logan
- Parasitology Department, Medical Faculty, Centre for Infectious Diseases, University Hospital Heidelberg, Heidelberg University, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Julia Bettina Mäurer
- Parasitology Department, Medical Faculty, Centre for Infectious Diseases, University Hospital Heidelberg, Heidelberg University, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Charlotte Wapler
- Parasitology Department, Medical Faculty, Centre for Infectious Diseases, University Hospital Heidelberg, Heidelberg University, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Victoria Anne Ingham
- Parasitology Department, Medical Faculty, Centre for Infectious Diseases, University Hospital Heidelberg, Heidelberg University, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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Ibrahim SS, Kouamo MFM, Muhammad A, Irving H, Riveron JM, Tchouakui M, Wondji CS. Functional Validation of Endogenous Redox Partner Cytochrome P450 Reductase Reveals the Key P450s CYP6P9a/- b as Broad Substrate Metabolizers Conferring Cross-Resistance to Different Insecticide Classes in Anopheles funestus. Int J Mol Sci 2024; 25:8092. [PMID: 39125661 PMCID: PMC11311542 DOI: 10.3390/ijms25158092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/10/2024] [Accepted: 06/13/2024] [Indexed: 08/12/2024] Open
Abstract
The versatility of cytochrome P450 reductase (CPR) in transferring electrons to P450s from other closely related species has been extensively exploited, e.g., by using An. gambiae CPR (AgCPR), as a homologous surrogate, to validate the role of An. funestus P450s in insecticide resistance. However, genomic variation between the AgCPR and An. funestus CPR (AfCPR) suggests that the full metabolism spectrum of An. funestus P450s might be missed when using AgCPR. To test this hypothesis, we expressed AgCPR and AfCPR side-by-side with CYP6P9a and CYP6P9b and functionally validated their role in the detoxification of insecticides from five different classes. Major variations were observed within the FAD- and NADP-binding domains of AgCPR and AfCPR, e.g., the coordinates of the second FAD stacking residue AfCPR-Y456 differ from that of AgCPR-His456. While no significant differences were observed in the cytochrome c reductase activities, when co-expressed with their endogenous AfCPR, the P450s significantly metabolized higher amounts of permethrin and deltamethrin, with CYP6P9b-AfCPR membrane metabolizing α-cypermethrin as well. Only the CYP6P9a-AfCPR membrane significantly metabolized DDT (producing dicofol), bendiocarb, clothianidin, and chlorfenapyr (bioactivation into tralopyril). This demonstrates the broad substrate specificity of An. funestus CYP6P9a/-b, capturing their role in conferring cross-resistance towards unrelated insecticide classes, which can complicate resistance management.
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Affiliation(s)
- Sulaiman S. Ibrahim
- Department of Biochemistry, Bayero University, Kano PMB 3011, Nigeria
- Center for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon; (M.F.M.K.); (J.M.R.); (M.T.)
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool L3 5QA, UK; (A.M.); (H.I.)
| | - Mersimine F. M. Kouamo
- Center for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon; (M.F.M.K.); (J.M.R.); (M.T.)
| | - Abdullahi Muhammad
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool L3 5QA, UK; (A.M.); (H.I.)
- Center of Biotechnology Research, Bayero University, Kano PMB 3011, Nigeria
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool L3 5QA, UK; (A.M.); (H.I.)
| | - Jacob M. Riveron
- Center for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon; (M.F.M.K.); (J.M.R.); (M.T.)
| | - Magellan Tchouakui
- Center for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon; (M.F.M.K.); (J.M.R.); (M.T.)
| | - Charles S. Wondji
- Center for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon; (M.F.M.K.); (J.M.R.); (M.T.)
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool L3 5QA, UK; (A.M.); (H.I.)
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Hancock PA, Ochomo E, Messenger LA. Genetic surveillance of insecticide resistance in African Anopheles populations to inform malaria vector control. Trends Parasitol 2024; 40:604-618. [PMID: 38760258 DOI: 10.1016/j.pt.2024.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/19/2024]
Abstract
Insecticide resistance in malaria vector populations poses a major threat to malaria control, which relies largely on insecticidal interventions. Contemporary vector-control strategies focus on combatting resistance using multiple insecticides with differing modes of action within the mosquito. However, diverse genetic resistance mechanisms are present in vector populations, and continue to evolve. Knowledge of the spatial distribution of these genetic mechanisms, and how they impact the efficacy of different insecticidal products, is critical to inform intervention deployment decisions. We developed a catalogue of genetic-resistance mechanisms in African malaria vectors that could guide molecular surveillance. We highlight situations where intervention deployment has led to resistance evolution and spread, and identify challenges in understanding and mitigating the epidemiological impacts of resistance.
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Affiliation(s)
- Penelope A Hancock
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Eric Ochomo
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Louisa A Messenger
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, USA; Parasitology and Vector Biology (PARAVEC) Laboratory, School of Public Health, University of Nevada, Las Vegas, USA
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Li H, Zhao P, Li S, Guo J, Hao D. Trial and error: New insights into recombinant expression of membrane-bound insect cytochromes P450 in Escherichia coli systems. Int J Biol Macromol 2024; 273:133183. [PMID: 38897522 DOI: 10.1016/j.ijbiomac.2024.133183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 06/02/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Insect cytochromes P450 (CYP450s) are key enzymes responsible for a wide array of oxidative transformations of both endogenous and exogenous substrates. However, there is currently no a universal guideline established for heterologous expression of membrane-bound CYP450s, which hampers their downstream biochemical and structural studies. In this study, we conducted large-scale screening of protein overexpression in Escherichia coli using 71 insect CYP450 sequences and optimized the expression of a difficult-to-express CYP450 (CYP6HX3) using eight different optimizations, including selection of host strains and expression vectors, alternative of leader signal peptides, and N-terminal modifications. We confirmed that 1) Only insect CYP450s belonging to the CYP347 family could be expressed with N-terminal fusion of ompA2+ signal peptide in E. coli expression system. 2) E. coli Lemo 21 (DE3) effectively improved the expression of CYP6HX3 in the plasma membrane. 3) A brick-red appearance occurred frequently in the expressed thallus or membrane proteins, but this phenomenon could not necessarily indicate successful overexpression of target CYP450s. These findings provide new insights into the recombinant expression of insect CYP450s in E. coli systems and will facilitate the theoretical approaches for functional expression and production of eukaryotic CYP450s.
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Affiliation(s)
- Hui Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Peiyuan Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Shouyin Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jinyan Guo
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Dejun Hao
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
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Li T, Liu R, Wang Q, Rao J, Liu Y, Dai Z, Gooneratne R, Wang J, Xie Q, Zhang X. A review of the influence of environmental pollutants (microplastics, pesticides, antibiotics, air pollutants, viruses, bacteria) on animal viruses. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133831. [PMID: 38402684 DOI: 10.1016/j.jhazmat.2024.133831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 02/09/2024] [Accepted: 02/17/2024] [Indexed: 02/27/2024]
Abstract
Microorganisms, especially viruses, cause disease in both humans and animals. Environmental chemical pollutants including microplastics, pesticides, antibiotics sand air pollutants arisen from human activities affect both animal and human health. This review assesses the impact of chemical and biological contaminants (virus and bacteria) on viruses including its life cycle, survival, mutations, loads and titers, shedding, transmission, infection, re-assortment, interference, abundance, viral transfer between cells, and the susceptibility of the host to viruses. It summarizes the sources of environmental contaminants, interactions between contaminants and viruses, and methods used to mitigate such interactions. Overall, this review provides a perspective of environmentally co-occurring contaminants on animal viruses that would be useful for future research on virus-animal-human-ecosystem harmony studies to safeguard human and animal health.
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Affiliation(s)
- Tong Li
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China
| | - Ruiheng Liu
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China
| | - Qian Wang
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China
| | - Jiaqian Rao
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China
| | - Yuanjia Liu
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, China
| | - Zhenkai Dai
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China
| | - Ravi Gooneratne
- Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Jun Wang
- College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China.
| | - Qingmei Xie
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China.
| | - Xinheng Zhang
- State Key Laboratory of Swine and Poultry Breeding Industry & Heyuan Branch, Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China; Guangdong Provincial Key Lab of AgroAnimal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Engineering Research Center for Vector Vaccine of Animal Virus, Guangzhou 510642, China.
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Fadel AN, Ibrahim SS, Sandeu MM, Tatsinkou CGM, Menze BD, Irving H, Hearn J, Nagi SC, Weedall GD, Terence E, Tchapga W, Wanji S, Wondji CS. Exploring the molecular mechanisms of increased intensity of pyrethroid resistance in Central African population of a major malaria vector Anopheles coluzzii. Evol Appl 2024; 17:e13641. [PMID: 38410533 PMCID: PMC10895554 DOI: 10.1111/eva.13641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/14/2023] [Accepted: 01/01/2024] [Indexed: 02/28/2024] Open
Abstract
Molecular mechanisms driving the escalation of pyrethroid resistance in the major malaria mosquitoes of Central Africa remain largely uncharacterized, hindering effective management strategies. Here, resistance intensity and the molecular mechanisms driving it were investigated in a population of Anopheles coluzzii from northern Cameroon. High levels of pyrethroid and organochloride resistance were observed in An. coluzzii population, with no mortality for 1× permethrin; only 11% and 33% mortalities for 5× and 10× permethrin diagnostic concentrations, and <2% mortalities for deltamethrin and DDT, respectively. Moderate bendiocarb resistance (88% mortality) and full susceptibility to malathion were observed. Synergist bioassays with piperonyl butoxide recovered permethrin susceptibility, with mortalities increasing to 53.39%, and 87.30% for 5× and 10× permethrin, respectively, implicating P450 monooxygenases. Synergist bioassays with diethyl maleate (DEM) recovered permethrin and DDT susceptibilities (mortalities increasing to 34.75% and 14.88%, respectively), implicating glutathione S-transferases. RNA-seq-based genome-wide transcriptional analyses supported by quantitative PCR identified glutathione S-transferase, GSTe2 (RNA-seqFC = 2.93 and qRT-PCRFC = 8.4, p < 0.0043) and CYP450, CYP6Z2 (RNA-seqFC = 2.39 and qRT-PCRFC = 11.7, p < 0.0177) as the most overexpressed detoxification genes in the pyrethroid-resistant mosquitoes, compared to mosquitoes of the susceptible Ngousso colony. Other overexpressed genes include P450s, CYP6M2 (FC = 1.68, p < 0.0114), CYP4G16 (FC = 2.02, p < 0.0005), and CYP4G17 (FC = 1.86, p < 0.0276). While high frequency of the 1014F kdr mutation (50%) and low frequencies of 1014S (6.61%) and 1575Y (10.29%) were observed, no ace-1 mutation was detected in bendiocarb-resistant populations, suggesting the preeminent role of metabolic mechanism. Overexpression of metabolic resistance genes (including GSTe2 and CYP6Z2 known to confer resistance to multiple insecticides) in An. coluzzii from the Sudan Savannah of Cameroon highlights the need for alternative management strategies to reduce malaria burden in northern Cameroon.
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Affiliation(s)
- Amen N. Fadel
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Sulaiman S. Ibrahim
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
- Department of BiochemistryBayero UniversityKanoNigeria
- Vector Biology DepartmentLiverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | - Maurice M. Sandeu
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
- Department of Microbiology and Infectious DiseasesSchool of Veterinary Medicine and SciencesUniversity of NgaoundéréNgaoundéréCameroon
| | | | | | - Helen Irving
- Vector Biology DepartmentLiverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | - Jack Hearn
- Centre of Epidemiology and Planetary HealthNorth FacultyVeterinary & Animal ScienceScotland's Rural CollegeInvernessUK
| | - Sanjay C. Nagi
- Vector Biology DepartmentLiverpool School of Tropical Medicine (LSTM)LiverpoolUK
| | - Gareth D. Weedall
- School of Biological and Environmental SciencesLiverpool John Moores UniversityLiverpoolUK
| | - Ebai Terence
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
| | - Williams Tchapga
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
| | - Samuel Wanji
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Charles S. Wondji
- Center for Research in Infectious Diseases (CRID)YaoundéCameroon
- Vector Biology DepartmentLiverpool School of Tropical Medicine (LSTM)LiverpoolUK
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Mmbaga AT, Lwetoijera DW. Current and future opportunities of autodissemination of pyriproxyfen approach for malaria vector control in urban and rural Africa. Wellcome Open Res 2023; 8:119. [PMID: 37440995 PMCID: PMC10333782 DOI: 10.12688/wellcomeopenres.19131.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2023] [Indexed: 07/15/2023] Open
Abstract
Despite the progress made in reducing malaria burden, new ways to address the increasing challenges of insecticide resistance and the invasion and spread of exotic malaria vectors such as Anopheles stephensi in Africa are urgently needed. While African countries are adopting larviciding as a complementary intervention for malaria vector control, the autodissemination technology has the potential to overcome barriers associated with the identification and treatment of prolific habitats that impede conventional larviciding approaches in rural settings. The autodissemination technology as a "lure and release" strategy works by exploiting the resting behavior of gravid mosquitoes to transfer lethal concentration of biological or chemical insecticide such as pyriproxyfen (PPF), an insect growth regulator (IGRs) to their oviposition sites and result in adult emergence inhibition. Despite the evidence of the autodissemination approach to control other mosquito-borne diseases, there is growing and promising evidence for its use in controlling malaria vectors in Africa, which highlights the momentous research that needs to be sustained. This article reviews the evidence for efficacy of the autodissemination approach using PPF and discusses its potential as efficient and affordable complementary malaria vector control intervention in Africa. In the previous studies that were done in controlled semi-field environments, autodissemination with PPF demonstrated its potential in reducing densities of captive population of malaria vectors such as Anopheles gambiae and Anopheles arabiensis. Of importance, empirical evidence and biology-informed mathematical models to demonstrate the utility of the autodissemination approach to control wild populations of malaria vectors under field environment either alone or in combination with other tools are underway. Among others, the key determining factors for future introduction of this approach at scale is having scalable autodissemination devices, optimized PPF formulations, assess its integration/complementarity to existing conventional larviciding, and community perception and acceptance of the autodissemination approach.
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Affiliation(s)
- Augustino Thabiti Mmbaga
- Environmental Health and Ecological Science Department, Ifakara Health Institute, Ifakara, Morogoro, P.O. Box 53, Tanzania
| | - Dickson Wilson Lwetoijera
- Environmental Health and Ecological Science Department, Ifakara Health Institute, Ifakara, Morogoro, P.O. Box 53, Tanzania
- School of Life Sciences and Bio Engineering, Nelson Mandela African Institution of Science and Technology, Tengeru, Arusha, P.O. Box 447, Tanzania
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Kunambi HJ, Ngowo H, Ali A, Urio N, Ngonzi AJ, Mwalugelo YA, Jumanne M, Mmbaga A, Tarimo FS, Swilla J, Okumu F, Lwetoijera D. Sterilized Anopheles funestus can autodisseminate sufficient pyriproxyfen to the breeding habitat under semi-field settings. Malar J 2023; 22:280. [PMID: 37735680 PMCID: PMC10515043 DOI: 10.1186/s12936-023-04699-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/01/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND Anopheles funestus, the main malaria vector, prefer to oviposit in permanent and/or semi-permanent breeding habitats located far from human dwellings. Difficulties in identifying and accessing these habitats jeopardize the feasibility of conventional larviciding. In this way, a semi-field study was conducted to assess the potential of autodissemination of pyriproxyfen (PPF) by An. funestus for its control. METHODS The study was conducted inside a semi-field system (SFS). Therein, two identical separate chambers, the treatment chamber with a PPF-treated clay pot (0.25 g AI), and the control chamber with an untreated clay pot. In both chambers, one artificial breeding habitat made of a plastic basin with one litre of water was provided. Three hundred blood-fed female An. funestus aged 5-9 days were held inside untreated and treated clay pots for 30 min and 48 h before being released for oviposition. The impact of PPF on adult emergence, fecundity, and fertility through autodissemination and sterilization effects were assessed by comparing the treatment with its appropriate control group. RESULTS Mean (95% CI) percentage of adult emergence was 15.5% (14.9-16.1%) and 70.3% (69-71%) in the PPF and control chamber for females exposed for 30 min (p < 0.001); and 19% (12-28%) and 95% (88-98%) in the PPF and control chamber for females exposed for 48 h (p < 0.001) respectively. Eggs laid by exposed mosquitoes and their hatch rate were significantly reduced compared to unexposed mosquitoes (p < 0.001). Approximately, 90% of females exposed for 48 h retained abnormal ovarian follicles and only 42% in females exposed for 30 min. CONCLUSION The study demonstrated sterilization and adult emergence inhibition via autodissemination of PPF by An. funestus. Also, it offers proof that sterilized An. funestus can transfer PPF to prevent adult emergence at breeding habitats. These findings warrant further assessment of the autodissemination of PPF in controlling wild population of An. funestus, and highlights its potential for complementing long-lasting insecticidal nets.
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Affiliation(s)
- Hamisi J Kunambi
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania.
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
- Tanzania Biotech Products Limited, The National Development Cooperation, P.O. Box 30119, Kibaha, Tanzania.
| | - Halfan Ngowo
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Ali Ali
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Naomi Urio
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Amos J Ngonzi
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Yohana A Mwalugelo
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- Department of Biomedical Sciences, Jaramogi Oginga Odinga University of Science and Technology, P.O. Box 210-40601, Bondo, Kenya
| | - Mohamed Jumanne
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
| | - Augustino Mmbaga
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania
| | - Felista S Tarimo
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania
| | - Joseph Swilla
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania
| | - Fredros Okumu
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania
- School of Public of Health, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa
- Institute of Biodiversity, Animal Health and, Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Dickson Lwetoijera
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 53, Ifakara, Tanzania.
- School of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
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9
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Yunta C, Ooi JMF, Oladepo F, Grafanaki S, Pergantis SA, Tsakireli D, Ismail HM, Paine MJI. Chlorfenapyr metabolism by mosquito P450s associated with pyrethroid resistance identifies potential activation markers. Sci Rep 2023; 13:14124. [PMID: 37644079 PMCID: PMC10465574 DOI: 10.1038/s41598-023-41364-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Chlorfenapyr is a pro-insecticide increasingly used in combination with pyrethroids such as a-cypermethrin or deltamethrin in insecticide treated bednets (ITNs) to control malaria transmitted by pyrethroid-resistant mosquito populations. Chlorfenapyr requires P450 activation to produce tralopyril and other bioactive metabolites. Pyrethroid resistance is often associated with elevated levels of chemoprotective P450s with broad substrate specificity, which could influence chlorfenapyr activity. Here, we have investigated chlorfenapyr metabolism by a panel of eight P450s commonly associated with pyrethroid resistance in An. gambiae and Ae. aegypti, the major vectors of malaria and arboviruses. Chlorfenapyr was activated to tralopyril by An. gambiae CYP6P3, CYP9J5, CYP9K1 and Ae. aegypti, CYP9J32. The Kcat/KM value of 0.66 μM-1 min-1 for CYP9K1 was, 6.7 fold higher than CYP6P3 and CYP9J32 (both 0.1 μM-1 min-1) and 22-fold higher than CYP9J5 (0.03 μM-1 min-1). Further investigation of the effect of -cypermethrin equivalent to the ratios used with chlorfenapyr in bed nets (~ 1:2 molar ratio) resulted in a reduction in chlorfenapyr metabolism by CYP6P3 and CYP6K1 of 76.8% and 56.8% respectively. This research provides valuable insights into the metabolism of chlorfenapyr by mosquito P450s and highlights the need for continued investigation into effective vector control strategies.
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Affiliation(s)
- Cristina Yunta
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Jocelyn M F Ooi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | | | - Sofia Grafanaki
- Department of Chemistry, University of Crete, Voutes Campus, Heraklion, 700 13, Greece
| | - Spiros A Pergantis
- Department of Chemistry, University of Crete, Voutes Campus, Heraklion, 700 13, Greece
| | - Dimitra Tsakireli
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Hellas, 100 N. Plastira Street, Heraklion, 700 13, Greece
- Laboratory of Pesticide Science, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos Street, Athens, 118 55, Greece
| | - Hanafy M Ismail
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
| | - Mark J I Paine
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
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10
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Soto A, Rowland M, Messenger LA, Kirby M, Mosha FW, Manjurano A, Protopopoff N. Ovary Dissection Is a Sensitive Measure of Sterility in Anopheles gambiae Exposed to the Insect Growth Regulator Pyriproxyfen. INSECTS 2023; 14:552. [PMID: 37367368 PMCID: PMC10299475 DOI: 10.3390/insects14060552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 06/28/2023]
Abstract
Pyriproxyfen (PPF) is an insect growth regulator used in the co-treatment of long-lasting insecticidal nets for its ability to sterilize female mosquitoes. To evaluate the efficacy of PPF-treated nets on mosquito reproductivity, most studies observe oviposition (egg-laying) rates in the laboratory. This technique has several technical disadvantages. Our study assessed if ovarial dissection could serve as an effective proxy for evaluating sterility in Anopheles gambiae mosquitoes. Blood-fed females were exposed to untreated or PPF-treated nets in cylinder assays and followed over several days to observe oviposition rates or egg development by dissection. For identifying PPF-exposed mosquitoes, both techniques demonstrated high sensitivity (oviposition: 99.1%; dissection: 100.0%), but for identifying non-exposed mosquitoes, specificity was significantly higher in the dissection group (52.5% vs. 18.9%). To assess whether dissection could be applied to nets treated with a pyrethroid or co-treated with a pyrethroid and PPF in tunnel tests, a blinded investigator performed dissections to predict the PPF exposure status across different treatment groups. The exposure status of dissected females was predicted with >90% accuracy. We report that dissection is a sensitive technique to assess sterility in female Anopheles gambiae mosquitoes and can be used as a predictor of PPF exposure.
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Affiliation(s)
- Alina Soto
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Mark Rowland
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Louisa A. Messenger
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV 89557, USA
| | - Mathew Kirby
- PMI VectorLink Project, Abt Associates, 6130 Executive Blvd., Rockville, MD 20852, USA
| | - Franklin W. Mosha
- Pan African Malaria Vector Research Consortium, Kilimanjaro Christian Medical University College, Moshi P.O. Box 2240, Tanzania
| | - Alphaxard Manjurano
- National Institute for Medical Research Tanzania, Mwanza P.O. Box 9653, Tanzania
| | - Natacha Protopopoff
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
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11
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Ibrahim SS, Muhammad A, Hearn J, Weedall GD, Nagi SC, Mukhtar MM, Fadel AN, Mugenzi LJ, Patterson EI, Irving H, Wondji CS. Molecular drivers of insecticide resistance in the Sahelo-Sudanian populations of a major malaria vector Anopheles coluzzii. BMC Biol 2023; 21:125. [PMID: 37226196 DOI: 10.1186/s12915-023-01610-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/03/2023] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND Information on common markers of metabolic resistance in malaria vectors from countries sharing similar eco-climatic characteristics can facilitate coordination of malaria control. Here, we characterized populations of the major malaria vector Anopheles coluzzii from Sahel region, spanning four sub-Saharan African countries: Nigeria, Niger, Chad and Cameroon. RESULTS Genome-wide transcriptional analysis identified major genes previously implicated in pyrethroid and/or cross-resistance to other insecticides, overexpressed across the Sahel, including CYP450s, glutathione S-transferases, carboxylesterases and cuticular proteins. Several, well-known markers of insecticide resistance were found in high frequencies-including in the voltage-gated sodium channel (V402L, I940T, L995F, I1527T and N1570Y), the acetylcholinesterase-1 gene (G280S) and the CYP4J5-L43F (which is fixed). High frequencies of the epidemiologically important chromosomal inversion polymorphisms, 2La, 2Rb and 2Rc, were observed (~80% for 2Rb and 2Rc). The 2La alternative arrangement is fixed across the Sahel. Low frequencies of these inversions (<10%) were observed in the fully insecticide susceptible laboratory colony of An. coluzzii (Ngoussou). Several of the most commonly overexpressed metabolic resistance genes sit in these three inversions. Two commonly overexpressed genes, GSTe2 and CYP6Z2, were functionally validated. Transgenic Drosophila melanogaster flies expressing GSTe2 exhibited extremely high DDT and permethrin resistance (mortalities <10% in 24h). Serial deletion of the 5' intergenic region, to identify putative nucleotide(s) associated with GSTe2 overexpression, revealed that simultaneous insertion of adenine nucleotide and a transition (T->C), between Forkhead box L1 and c-EST putative binding sites, were responsible for the high overexpression of GSTe2 in the resistant mosquitoes. Transgenic flies expressing CYP6Z2 exhibited marginal resistance towards 3-phenoxybenzylalcohol (a primary product of pyrethroid hydrolysis by carboxylesterases) and a type II pyrethroid, α-cypermethrin. However, significantly higher mortalities were observed in CYP6Z2 transgenic flies compared with controls, on exposure to the neonicotinoid, clothianidin. This suggests a possible bioactivation of clothianidin into a toxic intermediate, which may make it an ideal insecticide against populations of An. coluzzii overexpressing this P450. CONCLUSIONS These findings will facilitate regional collaborations within the Sahel region and refine implementation strategies through re-focusing interventions, improving evidence-based, cross-border policies towards local and regional malaria pre-elimination.
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Affiliation(s)
- Sulaiman S Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK.
- Department of Biochemistry, Bayero University, PMB 3011, Kano, Nigeria.
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Abdullahi Muhammad
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
- Centre for Biotechnology Research, Bayero University, PMB 3011, Kano, Nigeria
| | - Jack Hearn
- Centre of Epidemiology and Planetary Health, Veterinary & Animal Science, Scotland's Rural College, Inverness, IV2 5NA, UK
| | - Gareth D Weedall
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Sanjay C Nagi
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
| | | | - Amen N Fadel
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Leon J Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Edward I Patterson
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, L2S 3A1, Canada
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
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12
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Matowo NS, Kulkarni MA, Messenger LA, Jumanne M, Martin J, Mallya E, Lukole E, Mosha JF, Moshi O, Shirima B, Kaaya R, Rowland M, Manjurano A, Mosha FW, Protopopoff N. Differential impact of dual-active ingredient long-lasting insecticidal nets on primary malaria vectors: a secondary analysis of a 3-year, single-blind, cluster-randomised controlled trial in rural Tanzania. Lancet Planet Health 2023; 7:e370-e380. [PMID: 37164513 PMCID: PMC10186178 DOI: 10.1016/s2542-5196(23)00048-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 05/12/2023]
Abstract
BACKGROUND Gains in malaria control are threatened by widespread pyrethroid resistance in malaria vectors across sub-Saharan Africa. New long-lasting insecticidal nets (LLINs) containing two active ingredients (dual active-ingredient LLINs) have been developed to interrupt transmission in areas of pyrethroid resistance. We aimed to evaluate the effectiveness of three dual active-ingredient LLINs compared with standard pyrethroid LLINs against pyrethroid-resistant malaria vectors in rural Tanzania. METHODS In this study, we did a secondary analysis of entomological data from a four-group, 3 year, single-blind, cluster-randomised controlled trial carried out between Feb 18, 2019, and Dec 6, 2021. We conducted quarterly indoor mosquito collections using the Centers for Disease Control and Prevention light trap, in eight houses in each of the 84 study clusters in the Misungwi district, northwestern Tanzania. Anopheles vectors were then tested for malaria parasites and identified at species level, to distinguish between sibling species of the Anopheles gambiae and Anopheles funestus groups, using molecular laboratory techniques. The primary outcomes were density of different malaria vector species measured as the number of female Anopheles collected per household per night, the entomological inoculation rate (EIR), an indicator of malaria transmission, and sporozoite rate. Entomological outcomes were assessed on the basis of intention to treat, and the effect of the three dual active-ingredient LLINs was compared with the standard pyrethroid LLINs at household level. FINDINGS Dual active-ingredient LLINs had the greatest effect on Anopheles funestus sl, the most efficient vector in the study area, with comparatively weak effect on An arabiensis. An funestus density was 3∙1 per house per night in the pyrethroid LLIN group, 1∙2 in the chlorfenapyr pyrethroid LLIN group (adjusted density ratio [aDR]=0∙26, 95% CI 0∙17-0∙14, p<0∙0001), 1∙4 in the piperonyl-butoxide pyrethroid LLIN group (aDR=0∙49, 0∙32-0∙76, p=0∙0012), and 3∙0 in the pyriproxyfen pyrethroid LLIN group (aDR=0∙72, 0∙47-1∙11, p=0∙15). Malaria transmission intensity was also significantly lower in the chlorfenapyr pyrethroid group, with 0∙01 versus 0∙06 infective bites per household per night in the pyrethroid LLIN group (aDR=0∙21, 0∙14-0∙33, p<0∙0001). Ecological niche models indicated that vector-species distribution was stable following LLIN intervention despite the reductions observed in An funestus sl density. INTERPRETATION Chlorfenapyr pyrethroid LLINs were the most effective intervention against the main malaria vector An funestus sl over 3 years of community use, whereas the effect of piperonyl-butoxide pyrethroid LLIN was sustained for 2 years. The other vector, An arabiensis, was not controlled by any of the dual active-ingredient LLINs. Additional vector control tools and strategies targeted to locally prevalent vector species evading dual active-ingredient LLINs should be deployed to further reduce malaria transmission and achieve elimination. FUNDING The Department for International Development, UK Medical Research Council, Wellcome Trust, the Department of Health and Social Care, and The Bill & Melinda Gates Foundation via the Innovative Vector Control Consortium.
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Affiliation(s)
- Nancy S Matowo
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
| | - Manisha A Kulkarni
- School of Epidemiology and Public Health, University of Ottawa, OT, Canada
| | - Louisa A Messenger
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK; Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV, USA
| | - Mohamed Jumanne
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Jackline Martin
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Elizabeth Mallya
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Eliud Lukole
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Jacklin F Mosha
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Oliva Moshi
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Boniface Shirima
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Robert Kaaya
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Mark Rowland
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Alphaxard Manjurano
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Franklin W Mosha
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Natacha Protopopoff
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
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13
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Mmbaga AT, Lwetoijera DW. Current and future opportunities of autodissemination of pyriproxyfen approach for malaria vector control in urban and rural Africa. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.19131.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
Despite the progress made in reducing malaria burden, new ways to address the increasing challenges of insecticide resistance and the invasion and spread of exotic malaria vectors such as Anopheles stephensi in Africa are urgently needed. While African countries are adopting larviciding as a complementary intervention for malaria vector control, the autodissemination technology has the potential to overcome barriers associated with the identification and treatment of prolific habitats that impede conventional larviciding approaches in rural settings. The autodissemination technology as a “lure and release” strategy works by exploiting the resting behavior of gravid mosquitoes to transfer lethal concentration of biological or chemical insecticide such as pyriproxyfen (PPF), an insect growth regulator (IGRs) to their oviposition sites and result in adult emergence. Despite the evidence of the autodissemination approach to control other mosquito-borne diseases, there is growing and promising evidence for its use in controlling malaria vectors in Africa, which highlights the momentous research that needs to be sustained. This article reviews the evidence for efficacy of the autodissemination approach using PPF and discusses its potential as efficient and affordable complementary malaria vector control intervention in Africa. In the previous studies that were done in controlled semi-field environments, autodissemination with PPF demonstrated its potential in reducing densities of captive population of malaria vectors such as Anopheles gambiae and Anopheles arabiensis. Of importance, empirical evidence and biology-informed mathematical models to demonstrate the utility of the autodissemination approach to control wild populations of malaria vectors under field environment either alone or in combination with other tools are underway. Among others, the key determining factors for future introduction of this approach at scale is having scalable autodissemination devices, optimized PPF formulations, assess its integration/complementarity to existing conventional larviciding, and community perception and acceptance of the autodissemination approach.
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14
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You C, Zhang L, Song J, Zhang L, Zhen C, Gao X. The variation of a cytochrome P450 gene, CYP6G4, drives the evolution of Musca domestica L. (Diptera: Muscidae) resistance to insecticides in China. Int J Biol Macromol 2023; 236:123399. [PMID: 36775219 DOI: 10.1016/j.ijbiomac.2023.123399] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/16/2022] [Accepted: 01/19/2023] [Indexed: 02/12/2023]
Abstract
Long term and excessive insecticide use has resulted in some environmental problems and especially, insecticide resistance evolution in insect pests. The variation of cytochrome P450 monooxygenases (P450s), associated with the metabolic detoxification of toxic xenobiotics, is often involved in insecticide resistance. Here, we found that the variation in a P450 gene, CYP6G4, is the most important driver of carbamates resistance in the house fly (Musca domestica). Deciphering the detailed molecular mechanisms of the insecticide resistance is critical for performing suitable insecticide resistance management strategies. Our research results revealed that the combination of amino acid mutations (110C-330E-360N/S, 110C-330E-360S) of CYP6G4 could improve the resistance to propoxur. The nucleotide variations in the promoter region of CYP6G4 significantly increased the luciferase activity by the reporter gene assays. Additionally, miR-281-1-5p was confirmed to post-transcriptionally down-regulate the expression of CYP6G4. These findings suggest that three independent mechanisms; amino acid mutations of the P450 protein, mutations in the promoter region and low expression of post-trans-regulatory factors, as the powerful strategies for the insect resistance to toxic compounds, play a crucial role in the evolutionary processes of insecticide resistance.
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Affiliation(s)
- Chunmei You
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Lulu Zhang
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Jiajia Song
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Lei Zhang
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Congai Zhen
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Xiwu Gao
- Department of Entomology, China Agricultural University, Beijing 100193, China.
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15
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Wang P, Cui Q, Wang X, Liu Y, Zhang Y, Huang X, Jiang S, Jiang M, Bi L, Li B, Wei W, Pan Z. The inhibition of ecdysone signal pathway was the key of pyriproxyfen poisoning for silkworm, Bombyx mori. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 189:105307. [PMID: 36549814 DOI: 10.1016/j.pestbp.2022.105307] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 11/09/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Pyriproxyfen is a juvenile hormone-like pesticide. Once intake occurs, it leads to a series of poisoning characters consequences in silkworm, Bombyx mori (ID: 7091, Lepidoptera), such as non- cocooning, non-pupation, production of low-active eggs, and extended stages. However, the poisoning mechanism is still unclear. Here, silkworms were fed mulberry leaves soaked with different pyriproxyfen concentrations, and the heads were dissected for transcriptome analysis, while the hemolymph was used for determinations of ecdysone and juvenile hormone titers. As a result, after conjoint analysis of 3 feeding groups and a control group, 555 differentially expressed genes (DEGs) were obtained, which were mainly involved in hormone metabolism, glycometabolism and protein metabolism. Meanwhile, 119 genes were significantly correlated with the pyriproxyfen concentrations, and they were mainly involved in drug metabolism and glycometabolism. The ecdysone titers in several feeding groups were significantly lower than those of the control group, while juvenile hormone was not detected in all groups, including the control and feeding groups. Correspondingly, due to activation of the juvenile hormone signaling pathway by pyriproxyfen, key genes in the ecdysone synthesis pathway were downregulated, and a large number of downstream genes were up- or downregulated. In addition, nearly all genes in the detoxification pathway were upregulated. These results suggested that, affected by the juvenile hormone signaling pathway, ecdysone titers decreased and further affected a series of downstream processes, and this was the key reason for pyriproxyfen poisoning in silkworm, B. mori, which could lay a foundation for the study of pyriproxyfen resistance in silkworm.
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Affiliation(s)
- Pingyang Wang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China.
| | - Qiuying Cui
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Xia Wang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Yanwei Liu
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Yuli Zhang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Xuhua Huang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Shidong Jiang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Mangui Jiang
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Lihui Bi
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Biao Li
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Wei Wei
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China
| | - Zhixin Pan
- Guangxi Zhuang Autonomous Region Research Academy of Sericultural Science, Nanning, Guangxi 530007, PR China.
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16
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Campos KB, Alomar AA, Eastmond BH, Obara MT, Alto BW. Brazilian Populations of Aedes aegypti Resistant to Pyriproxyfen Exhibit Lower Susceptibility to Infection with Zika Virus. Viruses 2022; 14:v14102198. [PMID: 36298753 PMCID: PMC9606930 DOI: 10.3390/v14102198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022] Open
Abstract
Zika virus (ZIKV) infection has caused devastating consequences in Brazil as infections were associated with neurological complications in neonates. Aedes aegypti is the primary vector of ZIKV, and the evolution of insecticide resistance (IR) in this species can compromise control efforts. Although relative levels of phenotypic IR in mosquitoes can change considerably over time, its influence on vector competence for arboviruses is unclear. Pyriproxyfen (PPF)-resistant populations of Ae. aegypti were collected from five municipalities located in Northeast of Brazil, which demonstrated different resistance levels; low (Serrinha, Brumado), moderate (Juazeiro do Norte, Itabuna), and high (Quixadá). Experimental per os infection using ZIKV were performed with individuals from these populations and with an insecticide susceptible strain (Rockefeller) to determine their relative vector competence for ZIKV. Although all populations were competent to transmit ZIKV, mosquitoes derived from populations with moderate to high levels of IR exhibited similar or lower susceptibility to ZIKV infection than those from populations with low IR or the susceptible strain. These observations suggest an association between IR and arbovirus infection, which may be attributable to genetic hitchhiking. The use of PPF to control Brazilian Ae. aegypti may be associated with an indirect benefit of reduced susceptibility to infection, but no changes in disseminated infection and transmission of ZIKV among PPF-resistant phenotypes.
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Affiliation(s)
- Kauara Brito Campos
- Entomology and Nematology Department, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th SE, Vero Beach, FL 32962, USA
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília 70910-900, Brazil
- Coordenação Geral de Vigilância de Aboviroses, Secretaria de Vigilância em Saúde, Ministério da Saúde, Edifício PO 700, SRTV 702, Via W 5 Norte, Brasília 70723-040, Brazil
| | - Abdullah A. Alomar
- Entomology and Nematology Department, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th SE, Vero Beach, FL 32962, USA
| | - Bradley H. Eastmond
- Entomology and Nematology Department, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th SE, Vero Beach, FL 32962, USA
| | - Marcos Takashi Obara
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília 70910-900, Brazil
| | - Barry W. Alto
- Entomology and Nematology Department, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th SE, Vero Beach, FL 32962, USA
- Correspondence:
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17
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Hearn J, Djoko Tagne CS, Ibrahim SS, Tene-Fossog B, Mugenzi LMJ, Irving H, Riveron JM, Weedall GD, Wondji CS. Multi-omics analysis identifies a CYP9K1 haplotype conferring pyrethroid resistance in the malaria vector Anopheles funestus in East Africa. Mol Ecol 2022; 31:3642-3657. [PMID: 35546741 PMCID: PMC9321817 DOI: 10.1111/mec.16497] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/31/2022] [Accepted: 05/05/2022] [Indexed: 11/30/2022]
Abstract
Metabolic resistance to pyrethroids is a menace to the continued effectiveness of malaria vector controls. Its molecular basis is complex and varies geographically across Africa. Here, we used a multi‐omics approach, followed‐up with functional validation to show that a directionally selected haplotype of a cytochrome P450, CYP9K1 is a major driver of resistance in Anopheles funestus. A PoolSeq GWAS using mosquitoes alive and dead after permethrin exposure, from Malawi and Cameroon, detected candidate genomic regions, but lacked consistency across replicates. Targeted sequencing of candidate resistance genes detected several SNPs associated with known pyrethroid resistance QTLs. The most significant SNPs were in the cytochrome P450 CYP304B1 (Cameroon), CYP315A1 (Uganda) and the ABC transporter gene ABCG4 (Malawi). However, when comparing field resistant mosquitoes to laboratory susceptible, the pyrethroid resistance locus rp1 and SNPs around the ABC transporter ABCG4 were consistently significant, except for Uganda where SNPs in the P450 CYP9K1 was markedly significant. In vitro heterologous metabolism assays with recombinant CYP9K1 revealed that it metabolises type II pyrethroid (deltamethrin; 64% depletion) but not type I (permethrin; 0%), while moderately metabolising DDT (17%). CYP9K1 exhibited reduced genetic diversity in Uganda underlying an extensive selective sweep. Furthermore, a glycine to alanine (G454A) amino acid change in CYP9K1 was fixed in Ugandan mosquitoes but not in other An. funestus populations. This study sheds further light on the evolution of metabolic resistance in a major malaria vector by implicating more genes and variants that can be used to design field‐applicable markers to better track resistance Africa‐wide.
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Affiliation(s)
- Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Carlos S Djoko Tagne
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.,Department of Biochemistry, Faculty of Science, University of Bamenda, P.O. Box 39 Bambili, Bamenda, Cameroon
| | - Sulaiman S Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Billy Tene-Fossog
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Leon M J Mugenzi
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Jacob M Riveron
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Gareth D Weedall
- School of Biological and Environmental Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
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18
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Lees RS, Armistead JS, Azizi S, Constant E, Fornadel C, Gimnig JE, Hemingway J, Impoinvil D, Irish SR, Kisinza W, Lissenden N, Mawejje HD, Messenger LA, Moore S, Ngufor C, Oxborough R, Protopopoff N, Ranson H, Small G, Wagman J, Weetman D, Zohdy S, Spiers A. Strain Characterisation for Measuring Bioefficacy of ITNs Treated with Two Active Ingredients (Dual-AI ITNs): Developing a Robust Protocol by Building Consensus. INSECTS 2022; 13:434. [PMID: 35621770 PMCID: PMC9144861 DOI: 10.3390/insects13050434] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 02/04/2023]
Abstract
Durability monitoring of insecticide-treated nets (ITNs) containing a pyrethroid in combination with a second active ingredient (AI) must be adapted so that the insecticidal bioefficacy of each AI can be monitored independently. An effective way to do this is to measure rapid knock down of a pyrethroid-susceptible strain of mosquitoes to assess the bioefficacy of the pyrethroid component and to use a pyrethroid-resistant strain to measure the bioefficacy of the second ingredient. To allow robust comparison of results across tests within and between test facilities, and over time, protocols for bioefficacy testing must include either characterisation of the resistant strain, standardisation of the mosquitoes used for bioassays, or a combination of the two. Through a series of virtual meetings, key stakeholders and practitioners explored different approaches to achieving these goals. Via an iterative process we decided on the preferred approach and produced a protocol consisting of characterising mosquitoes used for bioefficacy testing before and after a round of bioassays, for example at each time point in a durability monitoring study. We present the final protocol and justify our approach to establishing a standard methodology for durability monitoring of ITNs containing pyrethroid and a second AI.
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Affiliation(s)
- Rosemary S. Lees
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (N.L.); (H.R.); (D.W.)
- Innovation to Impact, Pembroke Place, Liverpool L3 5QA, UK;
| | - Jennifer S. Armistead
- U.S. President’s Malaria Initiative (PMI), U.S. Agency for International Development (USAID), Washington, DC 20547, USA;
| | - Salum Azizi
- KCMUCo-PAMVERC Test Facility, Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi P.O. Box 2240, Tanzania;
| | - Edi Constant
- Centre Suisse de Recherches Scientifiques (CSRS), Abidjan 1303, Côte d’Ivoire;
| | - Christen Fornadel
- Innovative Vector Control Consortium (IVCC), Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (C.F.); (G.S.)
| | - John E. Gimnig
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA; (J.E.G.); (D.I.); (S.Z.)
| | - Janet Hemingway
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (N.L.); (H.R.); (D.W.)
| | - Daniel Impoinvil
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA; (J.E.G.); (D.I.); (S.Z.)
- U.S. President’s Malaria Initiative (PMI), Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA;
| | - Seth R. Irish
- U.S. President’s Malaria Initiative (PMI), Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA;
| | - William Kisinza
- Amani Research Centre, National Institute for Medical Research, Muheza P.O. Box 81, Tanzania;
| | - Natalie Lissenden
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (N.L.); (H.R.); (D.W.)
- Innovation to Impact, Pembroke Place, Liverpool L3 5QA, UK;
| | - Henry D. Mawejje
- Infectious Diseases Research Collaboration (IDRC), Plot 2C Nakasero Hill Road, Kampala P.O. Box 7475, Uganda;
| | - Louisa A. Messenger
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (L.A.M.); (C.N.); (N.P.)
| | - Sarah Moore
- Vector Control Product Testing Unit (VCPTU), Environmental Health and Ecological Science Department, Ifakara Health Institute, Bagamoyo P.O. Box 74, Tanzania;
- Vector Biology Unit, Department of Epidemiology and Public Health, Swiss Tropical & Public Health Institute, Kreuzstrasse 2, Allschwil, 4123 Basel, Switzerland
- Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland
- Nelson Mandela African Institute of Science and Technology (NM-AIST), Tengeru P.O. Box 447, Tanzania
| | - Corine Ngufor
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (L.A.M.); (C.N.); (N.P.)
- Centre de Recherche Entomologique de Cotonou, Cotonou BP 2604, Benin
| | - Richard Oxborough
- PMI VectorLink Project, Abt Associates, 6130 Executive Blvd., Rockville, MD 20852, USA;
| | - Natacha Protopopoff
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (L.A.M.); (C.N.); (N.P.)
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (N.L.); (H.R.); (D.W.)
| | - Graham Small
- Innovative Vector Control Consortium (IVCC), Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (C.F.); (G.S.)
| | - Joseph Wagman
- Malaria and Neglected Tropical Diseases Program, PATH, Washington, DC 20001, USA;
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (N.L.); (H.R.); (D.W.)
| | - Sarah Zohdy
- Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA; (J.E.G.); (D.I.); (S.Z.)
- U.S. President’s Malaria Initiative (PMI), Centers for Disease Control (CDC) and Prevention, Atlanta, GA 30329, USA;
| | - Angus Spiers
- Innovation to Impact, Pembroke Place, Liverpool L3 5QA, UK;
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Mosha JF, Kulkarni MA, Lukole E, Matowo NS, Pitt C, Messenger LA, Mallya E, Jumanne M, Aziz T, Kaaya R, Shirima BA, Isaya G, Taljaard M, Martin J, Hashim R, Thickstun C, Manjurano A, Kleinschmidt I, Mosha FW, Rowland M, Protopopoff N. Effectiveness and cost-effectiveness against malaria of three types of dual-active-ingredient long-lasting insecticidal nets (LLINs) compared with pyrethroid-only LLINs in Tanzania: a four-arm, cluster-randomised trial. Lancet 2022; 399:1227-1241. [PMID: 35339225 PMCID: PMC8971961 DOI: 10.1016/s0140-6736(21)02499-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/29/2021] [Accepted: 11/10/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) have successfully reduced malaria in sub-Saharan Africa, but their effectiveness is now partly compromised by widespread resistance to insecticides among vectors. We evaluated new classes of LLINs with two active ingredients with differing modes of action against resistant malaria vectors. METHODS We did a four-arm, cluster-randomised trial in Misungwi, Tanzania. Clusters were villages, or groups of hamlets, with at least 119 households containing children aged 6 months to 14 years living in the cluster's core area. Constrained randomisation was used to allocate clusters (1:1:1:1) to receive one of four types of LLIN treated with the following: α-cypermethrin only (pyrethroid-only [reference] group); pyriproxyfen and α-cypermethrin (pyriproxyfen group); chlorfenapyr and α-cypermethrin (chlorfenapyr group); or the synergist piperonyl butoxide and permethrin (piperonyl butoxide group). At least one LLIN was distributed for every two people. Community members and the field team were masked to group allocation. Malaria prevalence data were collected through cross-sectional surveys of randomly selected households from each cluster, in which children aged 6 months to 14 years were assessed for Plasmodium falciparum malaria infection by rapid diagnostic tests. The primary outcome was malaria infection prevalence at 24 months after LLIN distribution, comparing each of the dual-active-ingredient LLINs to the standard pyrethroid-only LLINs in the intention-to-treat population. The primary economic outcome was cost-effectiveness of dual-active-ingredient LLINs, based on incremental cost per disability-adjusted life-year (DALY) averted compared with pyrethroid-only LLINs, modelled over a 2-year period; we included costs of net procurement and malaria diagnosis and treatment, and estimated DALYs in all age groups. This study is registered with ClinicalTrials.gov (NCT03554616), and is ongoing but no longer recruiting. FINDINGS 84 clusters comprising 39 307 households were included in the study between May 11 and July 2, 2018. 147 230 LLINs were distributed among households between Jan 26 and Jan 28, 2019. Use of study LLINs was reported in 3155 (72·1%) of 4378 participants surveyed at 3 months post-distribution and decreased to 8694 (40·9%) of 21 246 at 24 months, with varying rates of decline between groups. Malaria infection prevalence at 24 months was 549 (45·8%) of 1199 children in the pyrethroid-only reference group, 472 (37·5%) of 1258 in the pyriproxyfen group (adjusted odds ratio 0·79 [95% CI 0·54-1·17], p=0·2354), 512 (40·7%) of 1259 in the piperonyl butoxide group (0·99 [0·67-1·45], p=0·9607), and 326 [25·6%] of 1272 in the chlorfenapyr group (0·45 [0·30-0·67], p=0·0001). Skin irritation or paraesthesia was the most commonly reported side-effect in all groups. Chlorfenapyr LLINs were the most cost-effective LLINs, costing only US$19 (95% uncertainty interval 1-105) more to public providers or $28 (11-120) more to donors per DALY averted over a 2-year period compared with pyrethroid-only LLINs, and saving costs from societal and household perspectives. INTERPRETATION After 2 years, chlorfenapyr LLINs provided significantly better protection than pyrethroid-only LLINs against malaria in an area with pyrethroid-resistant mosquitoes, and the additional cost of these nets would be considerably below plausible cost-effectiveness thresholds ($292-393 per DALY averted). Before scale-up of chlorfenapyr LLINs, resistance management strategies are needed to preserve their effectiveness. Poor textile and active ingredient durability in the piperonyl butoxide and pyriproxyfen LLINs might have contributed to their relative lack of effectiveness compared with standard LLINs. FUNDING Joint Global Health Trials scheme (UK Foreign, Commonwealth and Development Office; UK Medical Research Council; Wellcome; UK Department of Health and Social Care), US Agency for International Development, President's Malaria Initiative.
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Affiliation(s)
- Jacklin F Mosha
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Manisha A Kulkarni
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | - Eliud Lukole
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Nancy S Matowo
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Catherine Pitt
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, London, UK
| | - Louisa A Messenger
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Elizabeth Mallya
- Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Mohamed Jumanne
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Tatu Aziz
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Robert Kaaya
- Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Boniface A Shirima
- Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Gladness Isaya
- Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Monica Taljaard
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada; Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Jacklin Martin
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania; Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Ramadhan Hashim
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Charles Thickstun
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | - Alphaxard Manjurano
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Immo Kleinschmidt
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK; Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Franklin W Mosha
- Department of Parasitology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Mark Rowland
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Natacha Protopopoff
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
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20
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Nolden M, Paine MJI, Nauen R. Biochemical profiling of functionally expressed CYP6P9 variants of the malaria vector Anopheles funestus with special reference to cytochrome b 5 and its role in pyrethroid and coumarin substrate metabolism. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 182:105051. [PMID: 35249659 DOI: 10.1016/j.pestbp.2022.105051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Cytochrome P450 monooxygenases (P450s) are well studied enzymes catalyzing the oxidative metabolism of xenobiotics in insects including mosquitoes. Their duplication and upregulation in agricultural and public health pests such as anopheline mosquitoes often leads to an enhanced metabolism of insecticides which confers resistance. In the laboratory strain Anopheles funestus FUMOZ-R the duplicated P450s CYP6P9a and CYP6P9b are highly upregulated and proven to confer pyrethroid resistance. Microsomal P450 activity is regulated by NADPH cytochrome P450 oxidoreductase (CPR) required for electron transfer, whereas the modulatory role of cytochrome b5 (CYB5) on insect P450 activity is less clear. In previous studies CYP6P9a and CYP6P9b were recombinantly expressed in tandem with An. gambiae CPR using E. coli-expression systems and CYB5 added to the reaction mix to enhance activity. However, the precise role of CYB5 on substrate turn-over when combined with CYP6P9a and CYP6P9b remains poorly investigated, thus one objective of our study was to address this knowledge gap. In contrast to the CYP6P9 variants, the expression levels of both CYB5 and CPR were not upregulated in the pyrethroid resistant FUMOZ-R strain when compared to the susceptible FANG strain, suggesting no immediate regulatory role of these genes in pyrethroid resistance in FUMOZ-R. Here, for the first time we recombinantly expressed CYP6P9a and CYP6P9b from An. funestus in a baculovirus expression system using High-5 insect cells. Co-expression of each enzyme with CPR from either An. gambiae or An. funestus did not reveal noteworthy differences in catalytic capacity. Whereas the co-expression of An. funestus CYB5 - tested at different multiplicity of infection (MOI) ratios - resulted in a significantly higher metabolization of coumarin substrates as measured by fluorescence assays. This was confirmed by Michaelis-Menten kinetics using the most active substrate, 7-benzyloxymethoxy-4-trifluoromethylcoumarin (BOMFC). We observed a similar increase in coumarin substrate turnover by adding human CYB5 to the reaction mix. Finally, we compared by UPLC-MS/MS analysis the depletion rate of deltamethrin and the formation of 4'OH-deltamethrin by recombinantly expressed CYP6P9a and CYP6P9b with and without CYB5 and detected no difference in the extent of deltamethrin metabolism. Our results suggest that co-expression (or addition) of CYB5 with CYP6P9 variants, recombinantly expressed in insect cells, can significantly enhance their metabolic capacity to oxidize coumarins, but not deltamethrin.
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Affiliation(s)
- Melanie Nolden
- Bayer AG, Crop Science Division, Alfred Nobel Str. 50, D-40789 Monheim am Rhein, Germany; Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Mark J I Paine
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Ralf Nauen
- Bayer AG, Crop Science Division, Alfred Nobel Str. 50, D-40789 Monheim am Rhein, Germany.
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21
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Valbon W, Andreazza F, Oliveira EE, Liu F, Feng B, Hall M, Klimavicz J, Coats JR, Dong K. Bioallethrin activates specific olfactory sensory neurons and elicits spatial repellency in Aedes aegypti. PEST MANAGEMENT SCIENCE 2022; 78:438-445. [PMID: 34661374 PMCID: PMC8748403 DOI: 10.1002/ps.6682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/18/2021] [Indexed: 05/13/2023]
Abstract
BACKGROUND Use of pyrethroid insecticides is a pivotal strategy for mosquito control globally. Commonly known for their insecticidal activity by acting on voltage-gated sodium channels, pyrethroids, such as bioallethrin and transfluthrin, are used in mosquito coils, emanators and other vaporizers to repel mosquitoes and other biting arthropods. However, whether specific olfactory receptor neurons are activated by pyrethroids to trigger spatial repellency remains unknown. RESULTS We used behavioral and electrophysiological approaches to elucidate the mechanism of bioallethrin repellency in Aedes aegypti, a major vector of dengue, yellow fever, Zika and chikungunya viruses. We found that bioallethrin elicits spatial (i.e. non-contact) repellency and activates a specific type of olfactory receptor neuron in mosquito antennae. Furthermore, bioallethrin repellency is significantly reduced in a mosquito mutant of Orco, an obligate olfactory co-receptor that is essential for the function of odorant receptors (Ors). These results indicate that activation of specific Or(s) by bioallethrin contributes to bioallethrin repellency. In addition, bioallethrin repellency was reduced in a pyrethroid-resistant strain that carries two mutations in the sodium channel gene that are responsible for knockdown resistance (kdr) to pyrethroids, indicating a role of activation of sodium channels in bioallethrin repellency. CONCLUSION Results from this study show that bioallethrin repellency is likely to be the result of co-activation of Or(s) and sodium channels. These findings not only contribute to our understanding of the modes of action of volatile pyrethroids in spatial repellency, but also provide a framework for developing new repellents based on the dual-target mechanism revealed. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Wilson Valbon
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, MG, Brazil
- Department of Biology, Duke University, Durham, NC, USA
| | - Felipe Andreazza
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, MG, Brazil
- Department of Biology, Duke University, Durham, NC, USA
| | - Eugenio E. Oliveira
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Feng Liu
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Bo Feng
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Institute of Health and Environment, Wenzhou Medical University, Wenzhou, China
| | - Maura Hall
- Department of Entomology, Iowa State University, Ames, IA, USA
| | - James Klimavicz
- Department of Entomology, Iowa State University, Ames, IA, USA
| | - Joel R. Coats
- Department of Entomology, Iowa State University, Ames, IA, USA
| | - Ke Dong
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, MG, Brazil
- Corresponding author: (KD)
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22
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Katsavou E, Riga M, Ioannidis P, King R, Zimmer CT, Vontas J. Functionally characterized arthropod pest and pollinator cytochrome P450s associated with xenobiotic metabolism. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 181:105005. [PMID: 35082029 DOI: 10.1016/j.pestbp.2021.105005] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/12/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
The cytochrome P450 family (P450s) of arthropods includes diverse enzymes involved in endogenous essential physiological functions and in the oxidative metabolism of xenobiotics, insecticides and plant allelochemicals. P450s can also establish insecticide selectivity in bees and pollinators. Several arthropod P450s, distributed in different phylogenetic groups, have been associated with xenobiotic metabolism, and some of them have been functionally characterized, using different in vitro and in vivo systems. The purpose of this review is to summarize scientific publications on arthropod P450s from major insect and mite agricultural pests, pollinators and Papilio sp, which have been functionally characterized and shown to metabolize xenobiotics and/or their role (direct or indirect) in pesticide toxicity or resistance has been functionally validated. The phylogenetic relationships among these P450s, the functional systems employed for their characterization and their xenobiotic catalytic properties are presented, in a systematic approach, including critical aspects and limitations. The potential of the primary P450-based metabolic pathway of target and non-target organisms for the development of highly selective insecticides and resistance-breaking formulations may help to improve the efficiency and sustainability of pest control.
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Affiliation(s)
- Evangelia Katsavou
- Pesticide Science Laboratory, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
| | - Maria Riga
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology (FORTH), Nikolaou Plastira Street 100, 70013 Heraklion, Crete, Greece.
| | - Panagiotis Ioannidis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology (FORTH), Nikolaou Plastira Street 100, 70013 Heraklion, Crete, Greece
| | - Rob King
- Department of Computational and Analytical Sciences, Rothamsted Research, Harpenden, UK
| | - Christoph T Zimmer
- Syngenta Crop Protection, Werk Stein, Schaffhauserstrasse, Stein CH4332, Switzerland
| | - John Vontas
- Pesticide Science Laboratory, Department of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece; Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology (FORTH), Nikolaou Plastira Street 100, 70013 Heraklion, Crete, Greece.
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23
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Matowo J, Weetman D, Pignatelli P, Wright A, Charlwood JD, Kaaya R, Shirima B, Moshi O, Lukole E, Mosha J, Manjurano A, Mosha F, Rowland M, Protopopoff N. Expression of pyrethroid metabolizing P450 enzymes characterizes highly resistant Anopheles vector species targeted by successful deployment of PBO-treated bednets in Tanzania. PLoS One 2022; 17:e0249440. [PMID: 35073324 PMCID: PMC8786186 DOI: 10.1371/journal.pone.0249440] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 12/20/2021] [Indexed: 11/18/2022] Open
Abstract
Long lasting insecticidal nets (LLINs) are a proven tool to reduce malaria transmission, but in Africa efficacy is being reduced by pyrethroid resistance in the major vectors. A previous study that was conducted in Muleba district, Tanzania indicated possible involvement of cytochrome P450 monooxygenases in a pyrethroid resistance in An. gambiae population where pre-exposure to piperonyl butoxide (PBO) followed by permethrin exposure in CDC bottle bioassays led to partial restoration of susceptibility. PBO is a synergist that can block pyrethroid-metabolizing enzymes in a mosquito. Insecticide resistance profiles and underlying mechanisms were investigated in Anopheles gambiae and An. funestus from Muleba during a cluster randomized trial. Diagnostic dose bioassays using permethrin, together with intensity assays, suggest pyrethroid resistance that is both strong and very common, but not extreme. Transcriptomic analysis found multiple P450 genes over expressed including CYP6M2, CYP6Z3, CYP6P3, CYP6P4, CYP6AA1 and CYP9K1 in An. gambiae and CYP6N1, CYP6M7, CYP6M1 and CYP6Z1 in An. funestus. Indeed, very similar suites of P450 enzymes commonly associated with resistant populations elsewhere in Africa were detected as over expressed suggesting a convergence of mechanisms across Sub-Saharan African malaria vectors. The findings give insight into factors that may correlate with pyrethroid PBO LLIN success, broadly supporting model predictions, but revision to guidelines previously issued by the World Health Organization is warranted.
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Affiliation(s)
- Johnson Matowo
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
- * E-mail:
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Patricia Pignatelli
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Alexandra Wright
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jacques D. Charlwood
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Robert Kaaya
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Boniface Shirima
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Oliva Moshi
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Eliud Lukole
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Jacklin Mosha
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Alphaxard Manjurano
- Department of Parasitology, National Institute for Medical Research, Mwanza Medical Research Centre, Mwanza, Tanzania
| | - Franklin Mosha
- Department of Medical Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Mark Rowland
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Natacha Protopopoff
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Ingham VA, Tennessen JA, Lucas ER, Elg S, Yates HC, Carson J, Guelbeogo WM, Sagnon N, Hughes GL, Heinz E, Neafsey DE, Ranson H. Integration of whole genome sequencing and transcriptomics reveals a complex picture of the reestablishment of insecticide resistance in the major malaria vector Anopheles coluzzii. PLoS Genet 2021; 17:e1009970. [PMID: 34941884 PMCID: PMC8741062 DOI: 10.1371/journal.pgen.1009970] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/07/2022] [Accepted: 11/27/2021] [Indexed: 11/24/2022] Open
Abstract
Insecticide resistance is a major threat to gains in malaria control, which have been stalling and potentially reversing since 2015. Studies into the causal mechanisms of insecticide resistance are painting an increasingly complicated picture, underlining the need to design and implement targeted studies on this phenotype. In this study, we compare three populations of the major malaria vector An. coluzzii: a susceptible and two resistant colonies with the same genetic background. The original colonised resistant population rapidly lost resistance over a 6-month period, a subset of this population was reselected with pyrethroids, and a third population of this colony that did not lose resistance was also available. The original resistant, susceptible and re-selected colonies were subject to RNAseq and whole genome sequencing, which identified a number of changes across the transcriptome and genome linked with resistance. Firstly, an increase in the expression of genes within the oxidative phosphorylation pathway were seen in both resistant populations compared to the susceptible control; this translated phenotypically through an increased respiratory rate, indicating that elevated metabolism is linked directly with resistance. Genome sequencing highlighted several blocks clearly associated with resistance, including the 2Rb inversion. Finally, changes in the microbiome profile were seen, indicating that the microbial composition may play a role in the resistance phenotype. Taken together, this study reveals a highly complicated phenotype in which multiple transcriptomic, genomic and microbiome changes combine to result in insecticide resistance.
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Affiliation(s)
- Victoria A. Ingham
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Parasitology Unit, Universitätsklinikum Heidelberg, Heidelberg, Germany
| | - Jacob A. Tennessen
- The Broad Institute, Cambridge, Massachusetts, United States of America
- Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Eric R. Lucas
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sara Elg
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Jessica Carson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - N’Fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ougadougou, Burkina Faso
| | - Grant L. Hughes
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Eva Heinz
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Daniel E. Neafsey
- The Broad Institute, Cambridge, Massachusetts, United States of America
- Harvard TH Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Hilary Ranson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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25
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Li G, Lan H, Lu Q, He C, Wei Y, Mo D, Qu D, Xu K. The JH-Met2-Kr-h1 pathway is involved in pyriproxyfen-induced defects of metamorphosis and silk protein synthesis in silkworms, Bombyx mori. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 179:104980. [PMID: 34802530 DOI: 10.1016/j.pestbp.2021.104980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/19/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
Environmental residues of pryriproxyfen, a juvenile hormone analogue (JHA) type pesticide, may have on unintended consequences on non-target insects. However, the mechanism of pyriproxyfen action and silk protein synthesis in silkworms has not been reported. In the present study, we treated the silkworms with trace pyriproxyfen (1 × 10-4 mg/L) and found that the silkworm larvae showed no obvious poisoning symptoms, while the development of silk glands and cocoon-forming function were both seriously damaged due to the accumulation of pyriproxyfen in posterior silk gland (PSG). The titer of the juvenile hormone (JH) was increased, whereas the content of 20-hydroxyecdysone (20E) was reduced in pyriproxyfen-exposed hemolymph. Met2 is a component of the JH receptor complex and JH can promote its phosphorylation. We found Met2 and SRC were up-regulated in the larval stage after pyriproxyfen exposure, the JH-Met2/SRC complex led to the up-regulation of downstream genes Kr-h1, and Dimm, and then specifically inhibited the transcription of Fib-H. Meanwhile, the transcription of ecdysone inducible transcription factor Br-C Z4 was also inhibited by pyriproxyfen and resulted in the defects of metamorphosis. In conclusion, the trace pyriproxyfen could affect the metamorphosis and silk protein synthesis through the Met2-mediated pathway. Our study provided new evidence that Met2 might be a potential target gene of JHA in Lepidoptera.
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Affiliation(s)
- Guoli Li
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Huangli Lan
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Qingyu Lu
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Chunhui He
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Yuting Wei
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Danmei Mo
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Dacai Qu
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China; Sericulture Institute of Guangxi University, Guangxi University, Nanning, Guangxi 530004, PR China
| | - Kaizun Xu
- College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China; Sericulture Institute of Guangxi University, Guangxi University, Nanning, Guangxi 530004, PR China; National Demonstration Center for Experimental Plant Science Education, College of Agriculture, Guangxi University, Nanning, Guangxi 530004, PR China.
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26
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Valbon WR, Hatano E, Oliveira NRX, Ataíde ÁD, Corrêa MJM, Gomes SF, Martins GF, Haddi K, Alvarenga ES, Oliveira EE. Detrimental effects of pyriproxyfen on the detoxification and abilities of Belostoma anurum to prey upon Aedes aegypti larvae. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117130. [PMID: 33910136 DOI: 10.1016/j.envpol.2021.117130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/18/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Despite being effective in controlling mosquito larvae and a few other target organisms, the application of insecticides into aquatic systems may cause unintended alterations to the physiology or behavioral responses of several aquatic non-target organisms, which can ultimately lead to their death. Here, we firstly evaluated whether the susceptibility of the giant water bug, Belostoma anurum (Hemiptera: Belostomatidae), a predator of mosquito larvae, to pyriproxyfen would be similar to that of its potential prey, larvae of Aedes aegypti (Diptera: Culicidae). Secondly, we recorded the nominal concentrations of pyriproxyfen in water and evaluated whether sublethal exposures would lead to physiological or behavioral alterations on the B. anurum nymphs. We characterized the activities of three major families of detoxification enzymes (i.e., cytochrome P450 monooxygenases, glutathione-S-transferase, and general esterases) and further evaluated the abilities of pyriproxyfen sublethally-exposed B. anurum to prey upon A. aegypti larvae at different prey densities. Our findings revealed that nominal pyriproxyfen concentration significantly decreased (approximately 50%) over the first 24 h. Furthermore, when applied at the concentration of 10 μg a.i./L, pyriproxyfen was approximately four times more toxic to A. aegypti larvae (LT50 = 48 h) than to B. anurum nymphs (LT50 = 192 h). Interestingly, the pyriproxyfen sublethally-exposed (2.5 μg a.i./L) B. anurum nymphs exhibited reduced enzyme activities (cytochrome P450 monooxygenases) involved in detoxication processes and preyed significantly less on A. aegypti larvae when compared to unexposed predators. Collectively, our findings demonstrate that mortality-based pyriproxyfen risk assessments are not always protective of aquatic non-target organisms.
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Affiliation(s)
- Wilson R Valbon
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Eduardo Hatano
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | | | - Álvaro D Ataíde
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | | | - Sabriny F Gomes
- Departamento de Química, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Gustavo F Martins
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Khalid Haddi
- Departamento de Entomologia, Universidade Federal de Lavras, Lavras, MG, Brazil
| | - Elson S Alvarenga
- Departamento de Química, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Eugênio E Oliveira
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
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Wei Y, Cui J, Zhai W, Liu X, Zhou Z, Wang P, Liu D. Toxicity and fate of chiral insecticide pyriproxyfen and its metabolites in zebrafish (Danio rerio). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 280:116894. [PMID: 33774544 DOI: 10.1016/j.envpol.2021.116894] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
Pyriproxyfen is a juvenile hormone analogue insecticide used worldwide. At present, the potential threat of pyriproxyfen to aquatic organism has not been well explored. In this work, the bioaccumulation, metabolic profile and toxicity of pyriproxyfen and its metabolites to zebrafish were studied, and the enantioselectivity of pyriproxyfen and the major chiral metabolites were also determined. Sixteen metabolites of pyriproxyfen in zebrafish were identified. Hydroxylation, ether linkage cleavage and oxidation in phase I metabolism, followed by sulfate and glucuronic acid conjugation. The bioconcentration factors ranged from 1175 to 1246. Hydroxylation metabolites of pyriproxyfen showed enantioselective behavior in zebrafish with enantiomer fractions (EFs) of 4'-OH- pyriproxyfen and 5″-OH- pyriproxyfen ranged from 0.50 to 0.71. Toxicological indexes including acute toxicity, joint toxicity and oxidative stress were tested. Among all the metabolites, 4'-OH- pyriproxyfen was found 2 folds more toxic to zebrafish than pyriproxyfen. (-)-Pyriproxyfen was found 2 folds more toxic than rac- and (+)-pyriproxyfen. Antagonistic effects were found in binary joint toxicity of pyriproxyfen and its hydroxylated metabolites. Pyriproxyfen and its metabolites also showed oxidative stress damage by inhibiting the activity of CAT and SOD and increasing MDA. This work provided deep insight into the metabolism and the potential risks of pyriproxyfen to aquatic organisms.
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Affiliation(s)
- Yimu Wei
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Jingna Cui
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Wangjing Zhai
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Xueke Liu
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Zhiqiang Zhou
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Peng Wang
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China
| | - Donghui Liu
- Center for Pesticide Research, Department of Applied Chemistry, China Agricultural University, Beijing, 100193, China.
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28
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Grisales N, Lees RS, Maas J, Morgan JC, Wangrawa DW, Guelbeogo WM, N'Fale S, Lindsay SW, McCall PJ, Ranson H. Pyriproxyfen-treated bed nets reduce reproductive fitness and longevity of pyrethroid-resistant Anopheles gambiae under laboratory and field conditions. Malar J 2021; 20:273. [PMID: 34158066 PMCID: PMC8218427 DOI: 10.1186/s12936-021-03794-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/30/2021] [Indexed: 11/21/2022] Open
Abstract
Background The efficacy of insecticide-treated nets (ITNs) containing the insect growth regulator pyriproxyfen (PPF) and pyrethroid insecticides (PPF-ITNs) is being assessed in clinical trials to determine whether they provide greater protection from malaria than standard pyrethroid-treated ITNs in areas where mosquitoes are resistant to pyrethroids. Understanding the entomological mode of action of this new ITN class will aide interpretation of the results from these trials. Methods Anopheles gambiae sensu lato (s.l.) mosquitoes from a susceptible laboratory strain were exposed to PPF-treated netting 24 h, 6 h, and immediately prior to, or 24 h post blood feeding, and the impact on fecundity, fertility and longevity recorded. Pyrethroid-resistant populations were exposed to nets containing permethrin and PPF (PPF-ITNs) in cone bioassays and daily mortality recorded. Mosquitoes were also collected from inside houses pre- and post-distribution of PPF-ITNs in a clinical trial conduced in Burkina Faso; female An. gambiae s.l. were then assessed for fecundity and fertility. Results PPF exposure reduced the median adult lifespan of insecticide-susceptible mosquitoes by 4 to 5 days in all exposure times (p < 0.05) other than 6 h pre-blood meal and resulted in almost complete lifelong sterilization. The longevity of pyrethroid-resistant mosquitoes was also reduced by at least 5 days after exposure to PPF-ITNs compared to untreated nets, but was unaffected by exposure to standard pyrethroid only ITNs. A total of 386 blood-fed or gravid An. gambiae s.l. females were collected from five villages between 1 and 12 months before distribution of PPF-ITNs. Of these mosquitoes, 75% laid eggs and the remaining 25% appeared to have normal ovaries upon dissection. In contrast, only 8.6% of the 631 blood-fed or gravid An. gambiae s.l. collected post PPF-ITN distribution successfully oviposited; 276 (43.7%) did not oviposit but had apparently normal ovaries upon dissection, and 301 (47.7%) did not oviposit and had abnormal eggs upon dissection. Egg numbers were also significantly lower (average of 138/female prior distribution vs 85 post distribution, p < 0.05). Conclusion Exposure to a mixture of PPF and pyrethroids on netting shortens the lifespan of mosquitoes and reduces reproductive output. Sterilization of vectors lasted at least one year under operational conditions. These findings suggest a longer effective lifespan of PPF-pyrethroid nets than reported previously. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03794-z.
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Affiliation(s)
- Nelson Grisales
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.,World Mosquito Programme, Action On Poverty, Level 4, President Place, No. 93 Nguyen Du Street, District 1, Ho Chi Minh City, Vietnam
| | - Rosemary S Lees
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - James Maas
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - John C Morgan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Dimitri W Wangrawa
- Centre National de Recherche Et de Formation Sur Le Paludisme (CNRFP), Rue 1847 Avenue Kunda Yonré, 01 BP 2208, Ouagadougou, Burkina Faso
| | - Wamdaogo M Guelbeogo
- Centre National de Recherche Et de Formation Sur Le Paludisme (CNRFP), Rue 1847 Avenue Kunda Yonré, 01 BP 2208, Ouagadougou, Burkina Faso
| | - Sagnon N'Fale
- Centre National de Recherche Et de Formation Sur Le Paludisme (CNRFP), Rue 1847 Avenue Kunda Yonré, 01 BP 2208, Ouagadougou, Burkina Faso
| | - Steven W Lindsay
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK
| | - Philip J McCall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
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Ingham VA, Brown F, Ranson H. Transcriptomic analysis reveals pronounced changes in gene expression due to sub-lethal pyrethroid exposure and ageing in insecticide resistance Anopheles coluzzii. BMC Genomics 2021; 22:337. [PMID: 33971808 PMCID: PMC8111724 DOI: 10.1186/s12864-021-07646-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 04/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria control is heavily reliant on the use of insecticides that target and kill the adult female Anopheline vector. The intensive use of insecticides of the pyrethroid class has led to widespread resistance in mosquito populations. The intensity of pyrethroid resistance in some settings in Africa means mosquitoes can contact bednets treated with this insecticide class multiple times with minimal mortality effects. Furthermore, both ageing and diel cycle have been shown to have large impacts on the resistance phenotype. Together, these traits may affect other aspects of vector biology controlling the vectorial capacity or fitness of the mosquito. RESULTS Here we show that sublethal exposure of a highly resistant Anopheles coluzzii population originally from Burkina Faso to the pyrethroid deltamethrin results in large and sustained changes to transcript expression. We identify five clear patterns in the data showing changes to transcripts relating to: DNA repair, respiration, translation, behaviour and oxioreductase processes. Further, we highlight differential regulation of transcripts from detoxification families previously linked with insecticide resistance, in addition to clear down-regulation of the oxidative phosphorylation pathway both indicative of changes in metabolism post-exposure. Finally, we show that both ageing and diel cycle have major effects on known insecticide resistance related transcripts. CONCLUSION Sub-lethal pyrethroid exposure, ageing and the diel cycle results in large-scale changes in the transcriptome of the major malaria vector Anopheles coluzzii. Our data strongly supports further phenotypic studies on how transcriptional changes such as reduced expression of the oxidative phosphorylation pathway or pyrethroid induced changes to redox state might impact key mosquito traits, such as vectorial capacity and life history traits.
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Affiliation(s)
- V A Ingham
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK. .,Present Address: Parasitology Unit, Centre for Infectious Diseases, Universitätsklinikum, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
| | - F Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK.,Department of Epidemiology and Population Health, Institute of Infection and Global Health, Faculty of Health and Life Sciences, Leahurst Campus, University of Liverpool, Neston, CH647TE, UK
| | - H Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
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Naeem A, Hafeez F, Iftikhar A, Waaiz M, Güncan A, Ullah F, Shah FM. Laboratory induced selection of pyriproxyfen resistance in Oxycarenus hyalinipennis Costa (Hemiptera: Lygaeidae): Cross-resistance potential, realized heritability, and fitness costs determination using age-stage, two-sex life table. CHEMOSPHERE 2021; 269:129367. [PMID: 33388567 DOI: 10.1016/j.chemosphere.2020.129367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
Pyriproxyfen is a biorational insecticide from IGR family, used worldwide against several economic pests. To evaluate the risk of pyriproxyfen resistance in dusky cotton bug, Oxycarenus hyalinipennis Costa (Hemiptera: Lygaeidae), a major concern for cotton producers, and to formulate strategies effective to tackle resistance, a field collected population was selected with pyriproxyfen under laboratory conditions using seed-dip method. A resistant strain designated as Pyr-SEL (G18) was developed after repeatedly selecting O. hyalinipennis with pyriproxyfen over eighteen generations. Thereafter, fitness costs, realized heritability (h2) and cross-resistance were investigated. As a result of selection, Pyr-SEL (G18) developed a very high level of resistance (resistance ratio = 464.23-fold) compared with the susceptible strain unselected over twenty generations Un-SEL (G20). The Pyr-SEL (G18) conferred strong cross-resistance to bifenthrin (146.59-fold), lambda-cyhalothrin (132.96-fold) and fenoxycarb (91.06-fold), whereas showed moderate cross-resistance to diafenthiuron (28.86-fold) and fipronil (22.73-fold). The h2 estimate was 0.16 in Pyr-SEL (G18). The developmental duration of O. hyalinipennis pre-adult prolonged, but traits of λ, r and R0 reduced in Pyr-SEL (G18) compared with the Un-SEL (G20). Also, the population projection obtained lower population size for Pyr-SEL (G18) than Un-SEL (G20). Fitness studies revealed that high resistance development to pyriproxyfen lowered the relative fitness of Pyr-SEL (G18) (Rf = 0.38) compared with the Un-SEL (G20). These findings may be practically valuable in tackling O. hyalinipennis resistance for better pest management.
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Affiliation(s)
- Afifa Naeem
- Entomological Research Institute, Ayub Agricultural Research Institute, Faisalabad, Punjab, Pakistan; Department of Entomology, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya, Multan, Pakistan
| | - Faisal Hafeez
- Entomological Research Institute, Ayub Agricultural Research Institute, Faisalabad, Punjab, Pakistan
| | - Ayesha Iftikhar
- Entomological Research Institute, Ayub Agricultural Research Institute, Faisalabad, Punjab, Pakistan
| | - Muhammad Waaiz
- Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Ali Güncan
- Department of Plant Protection, Faculty of Agriculture, Ordu University, 52200, Ordu, Turkey
| | - Farman Ullah
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Farhan Mahmood Shah
- Department of Entomology, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya, Multan, Pakistan.
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Opiyo MA, Ngowo HS, Mapua SA, Mpingwa M, Nchimbi N, Matowo NS, Majambere S, Okumu FO. Sub-lethal aquatic doses of pyriproxyfen may increase pyrethroid resistance in malaria mosquitoes. PLoS One 2021; 16:e0248538. [PMID: 33735241 PMCID: PMC7971891 DOI: 10.1371/journal.pone.0248538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/01/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Pyriproxyfen (PPF), an insect growth hormone mimic is widely used as a larvicide and in some second-generation bed nets, where it is combined with pyrethroids to improve impact. It has also been evaluated as a candidate for auto-dissemination by adult mosquitoes to control Aedes and Anopheles species. We examined whether PPF added to larval habitats of pyrethroid-resistant malaria vectors can modulate levels of resistance among emergent adult mosquitoes. METHODOLOGY Third-instar larvae of pyrethroid-resistant Anopheles arabiensis (both laboratory-reared and field-collected) were reared in different PPF concentrations, between 1×10-9 milligrams active ingredient per litre of water (mgAI/L) and 1×10-4 mgAI/L, or no PPF at all. Emergent adults escaping these sub-lethal exposures were tested using WHO-standard susceptibility assays on pyrethroids (0.75% permethrin and 0.05% deltamethrin), carbamates (0.1% bendiocarb) and organochlorides (4% DDT). Biochemical basis of pyrethroid resistance was investigated by pre-exposure to 4% PBO. Bio-efficacies of long-lasting insecticide-treated nets, Olyset® and PermaNet 2.0 were also examined against adult mosquitoes with or without previous aquatic exposure to PPF. RESULTS Addition of sub-lethal doses of PPF to larval habitats of pyrethroid-resistant An. arabiensis, consistently resulted in significantly reduced mortalities of emergent adults when exposed to pyrethroids, but not to bendiocarb or DDT. Mortality rates after exposure to Olyset® nets, but not PermaNet 2.0 were also reduced following aquatic exposures to PPF. Pre-exposure to PBO followed by permethrin or deltamethrin resulted in significant increases in mortality, compared to either insecticide alone. CONCLUSIONS Partially-resistant mosquitoes exposed to sub-lethal aquatic concentrations of PPF may become more resistant to pyrethroids than they already are without such pre-exposures. Studies should be conducted to examine whether field applications of PPF, either by larviciding or other means actually exacerbates pyrethroid-resistance in areas where signs of such resistance already exist in wild the vector populations. The studies should also investigate mechanisms underlying such magnification of resistance, and how this may impact the potential of PPF-based interventions in areas with pyrethroid resistance.
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Affiliation(s)
- Mercy A. Opiyo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Barcelona Institute for Global Health (ISGlobal), Hospital Clinic, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Halfan S. Ngowo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health, and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Salum A. Mapua
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Monica Mpingwa
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Nuru Nchimbi
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
| | - Nancy S. Matowo
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Silas Majambere
- Pan African Mosquito Control Association, PAMCA, KEMRI Headquarters, Nairobi, Kenya
| | - Fredros O. Okumu
- Environmental Health and Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania
- Institute of Biodiversity, Animal Health, and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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Muhammad A, Ibrahim SS, Mukhtar MM, Irving H, Abajue MC, Edith NMA, Da’u SS, Paine MJI, Wondji CS. High pyrethroid/DDT resistance in major malaria vector Anopheles coluzzii from Niger-Delta of Nigeria is probably driven by metabolic resistance mechanisms. PLoS One 2021; 16:e0247944. [PMID: 33705436 PMCID: PMC7951933 DOI: 10.1371/journal.pone.0247944] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/17/2021] [Indexed: 11/18/2022] Open
Abstract
Entomological surveillance of local malaria vector populations is an important component of vector control and resistance management. In this study, the resistance profile and its possible mechanisms was characterised in a field population of the major malaria vector Anopheles coluzzii from Port Harcourt, the capital of Rivers state, in the Niger-Delta Region of Nigeria. Larvae collected in Port-Harcourt, were reared to adulthood and used for WHO bioassays. The population exhibited high resistance to permethrin, deltamethrin and DDT with mortalities of 6.7% ± 2.4, 37.5% ± 3.2 and 6.3% ± 4.1, respectively, but were fully susceptible to bendiocarb and malathion. Synergist bioassays with piperonylbutoxide (PBO) partially recovered susceptibility, with mortalities increasing to 53% ± 4, indicating probable role of CYP450s in permethrin resistance (χ2 = 29.48, P < 0.0001). Transcriptional profiling revealed five major resistance-associated genes overexpressed in the field samples compared to the fully susceptible laboratory colony, Ngoussou. Highest fold change (FC) was observed with GSTe2 (FC = 3.3 in permethrin exposed and 6.2 in unexposed) and CYP6Z3 (FC = 1.4 in exposed and 4.6 in unexposed). TaqMan genotyping of 32 F0 females detected the 1014F and 1575Y knockdown resistance (kdr) mutations with frequencies of 0.84 and 0.1, respectively, while 1014S mutation was not detected. Sequencing of a fragment of the voltage-gated sodium channel, spanning exon 20 from 13 deltamethrin-resistant and 9 susceptible females revealed only 2 distinct haplotypes with a low haplotype diversity of 0.33. The findings of high pyrethroid resistance but with a significant degree of recovery after PBO synergist assay suggests the need to move to PBO-based nets. This could be complemented with carbamate- or organophosphate-based indoor residual spraying in this area.
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Affiliation(s)
- Abdullahi Muhammad
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
- Centre for Biotechnology Research, Bayero University, Kano, Nigeria
| | - Sulaiman S. Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
- Department of Biochemistry, Bayero University, Kano, Nigeria
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Maduamaka C. Abajue
- Department of Animal and Environmental Biology, University of Port Harcourt, Port Harcourt, Nigeria
| | - Noutcha M. A. Edith
- Department of Animal and Environmental Biology, University of Port Harcourt, Port Harcourt, Nigeria
| | - Sabitu S. Da’u
- Department of Science, School of Continuing Education, Bayero University, Kano, Nigeria
| | - Mark J. I. Paine
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Charles S. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
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Accrombessi M, Cook J, Ngufor C, Sovi A, Dangbenon E, Yovogan B, Akpovi H, Hounto A, Thickstun C, Padonou GG, Tokponnon F, Messenger LA, Kleinschmidt I, Rowland M, Akogbeto MC, Protopopoff N. Assessing the efficacy of two dual-active ingredients long-lasting insecticidal nets for the control of malaria transmitted by pyrethroid-resistant vectors in Benin: study protocol for a three-arm, single-blinded, parallel, cluster-randomized controlled trial. BMC Infect Dis 2021; 21:194. [PMID: 33607958 PMCID: PMC7892705 DOI: 10.1186/s12879-021-05879-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/09/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) are currently the primary method of malaria control in sub-Saharan Africa and have contributed to a significant reduction in malaria burden over the past 15 years. However, this progress is threatened by the wide-scale selection of insecticide-resistant malaria vectors. It is, therefore, important to accelerate the generation of evidence for new classes of LLINs. METHODS This protocol presents a three-arm superiority, single-blinded, cluster randomized controlled trial to evaluate the impact of 2 novel dual-active ingredient LLINs on epidemiological and entomological outcomes in Benin, a malaria-endemic area with highly pyrethroid-resistant vector populations. The study arms consist of (i) Royal Guard® LLIN, a net combining a pyrethroid (alpha-cypermethrin) plus an insect growth regulator (pyriproxyfen), which in the adult female is known to disrupt reproduction and egg fertility; (ii) Interceptor G2® LLIN, a net incorporating two adulticides (alpha-cypermethrin and chlorfenapyr) with different modes of action; and (iii) the control arm, Interceptor® LLIN, a pyrethroid (alpha-cypermethrin) only LLIN. In all arms, one net for every 2 people will be distributed to each household. Sixty clusters were identified and randomised 1:1:1 to each study arm. The primary outcome is malaria case incidence measured over 24 months through active case detection in a cohort of 25 children aged 6 months to 10 years, randomly selected from each cluster. Secondary outcomes include 1) malaria infection prevalence (all ages) and prevalence of moderate to severe anaemia in children under 5 years old, measured at 6 and 18 months post-intervention; 2) entomological indices measured every 3 months using human landing catches over 24 months. Insecticide resistance intensity will also be monitored over the study period. DISCUSSION This study is the second cluster randomised controlled trial to evaluate the efficacy of these next-generation LLINs to control malaria transmitted by insecticide-resistant mosquitoes. The results of this study will form part of the WHO evidence-based review to support potential public health recommendations of these nets and shape malaria control strategies of sub-Saharan Africa for the next decade. TRIAL REGISTRATION ClinicalTrials.gov, NCT03931473 , registered on 30 April 2019.
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Affiliation(s)
- Manfred Accrombessi
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK.
| | - Jackie Cook
- Medical Research Council (MRC) International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | - Corine Ngufor
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | - Arthur Sovi
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
- Faculty of Agronomy, University of Parakou, Parakou, Benin
| | | | - Boulais Yovogan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Hilaire Akpovi
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Aurore Hounto
- National Malaria Control Program, Ministry of Health, Cotonou, Benin
| | - Charles Thickstun
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Gil G Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | | | - Louisa A Messenger
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | - Immo Kleinschmidt
- Medical Research Council (MRC) International Statistics and Epidemiology Epidemiology Group, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
- School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
- Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
| | - Mark Rowland
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
| | | | - Natacha Protopopoff
- Faculty of Infectious and Tropical Diseases, Disease Control Department, London School of Hygiene and Tropical Medicine, WC1E 7HT, London, UK
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Assessing cross-resistance within the pyrethroids in terms of their interactions with key cytochrome P450 enzymes and resistance in vector populations. Parasit Vectors 2021; 14:115. [PMID: 33602297 PMCID: PMC7893915 DOI: 10.1186/s13071-021-04609-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/23/2021] [Indexed: 01/21/2023] Open
Abstract
Background It is important to understand whether the potential impact of pyrethroid resistance on malaria control can be mitigated by switching between different pyrethroids or whether cross-resistance within this insecticide class precludes this approach. Methods Here we assess the relationships among pyrethroids in terms of their binding affinity to, and depletion by, key cytochrome P450 enzymes (hereafter P450s) that are known to confer metabolic pyrethroid resistance in Anopheles gambiae (s.l.) and An. funestus, in order to identify which pyrethroids may diverge from the others in their vulnerability to resistance. We then investigate whether these same pyrethroids also diverge from the others in terms of resistance in vector populations. Results We found that the type I and II pyrethroids permethrin and deltamethrin, respectively, are closely related in terms of binding affinity to key P450s, depletion by P450s and resistance within vector populations. Bifenthrin, which lacks the common structural moiety of most pyrethroids, diverged from the other pyrethroids tested in terms of both binding affinity to key P450s and depletion by P450s, but resistance to bifenthrin has rarely been tested in vector populations and was not analysed here. Etofenprox, which also lacks the common structural moiety of most pyrethroids, diverged from the more commonly deployed pyrethroids in terms of binding affinity to key P450s and resistance in vector populations, but did not diverge from these pyrethroids in terms of depletion by the P450s. The analysis of depletion by the P450s indicated that etofenprox may be more vulnerable to metabolic resistance mechanisms in vector populations. In addition, greater resistance to etofenprox was found across Aedes aegypti populations, but greater resistance to this compound was not found in any of the malaria vector species analysed. The results for pyrethroid depletion by anopheline P450s in the laboratory were largely not repeated in the findings for resistance in malaria vector populations. Conclusion Importantly, the prevalence of resistance to the pyrethroids α-cypermethrin, cyfluthrin, deltamethrin, λ-cyhalothrin and permethrin was correlated across malaria vector populations, and switching between these compounds as a tool to mitigate against pyrethroid resistance is not advised without strong evidence supporting a true difference in resistance.![]()
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Nauen R, Zimmer CT, Vontas J. Heterologous expression of insect P450 enzymes that metabolize xenobiotics. CURRENT OPINION IN INSECT SCIENCE 2021; 43:78-84. [PMID: 33186746 DOI: 10.1016/j.cois.2020.10.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 10/28/2020] [Indexed: 06/11/2023]
Abstract
Insect cytochrome P450-monooxygenases (P450s) are an enzyme superfamily involved in the oxidative transformation of endogenous and exogenous substrates, including insecticides. They were also shown to determine insecticide selectivity in beneficial arthropods such as bee pollinators, and to detoxify plant secondary metabolites. The recent explosion in numbers of P450s due to increased invertebrate genomes sequenced, allowed researchers to study their functional relevance for xenobiotic metabolism by recombinant expression using different expression systems. Troubleshooting strategies, including different systems and protein modifications typically adapted from mammalian P450s, have been applied to improve the functional expression, with partial success. The aim of this mini review is to critically summarize different strategies recently developed and used to produce recombinant insect P450s for xenobiotic metabolism studies.
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Affiliation(s)
- Ralf Nauen
- Bayer AG, Crop Science Division, R&D, Alfred Nobel-Strasse 50, 40789 Monheim, Germany.
| | - Christoph T Zimmer
- Syngenta Crop Protection, Werk Stein, Schaffhauserstrasse, Stein CH4332, Switzerland
| | - John Vontas
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology (FORTH), Nikolaou Plastira Street 100, 70013, Heraklion, Crete, Greece; Pesticide Science Laboratory, Department of Crop Science, Agricultural University of Athens, Iera Odos 9 75, 11855, Athens, Greece.
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Sakka MK, Riga M, Ioannidis P, Baliota GV, Tselika M, Jagadeesan R, Nayak MK, Vontas J, Athanassiou CG. Transcriptomic analysis of s-methoprene resistance in the lesser grain borer, Rhyzopertha dominica, and evaluation of piperonyl butoxide as a resistance breaker. BMC Genomics 2021; 22:65. [PMID: 33472593 PMCID: PMC7819154 DOI: 10.1186/s12864-020-07354-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 12/27/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The lesser grain borer, Rhyzopertha dominica is a serious pest of stored grains. Fumigation and contact insecticides play a major role in managing this pest globally. While insects are developing genetic resistance to chemicals, hormonal analogues such as s-methoprene play a key role in reducing general pest pressure as well as managing pest populations that are resistant to fumigants and neurotoxic contact insecticides. However, resistance to s-methoprene has been reported in R. dominica with some reports showing a remarkable high resistance, questioning the use of this compound and other related analogues in grain protection. The current study attempts to identify possible molecular mechanisms that contribute in resistance to s-methoprene in R. dominica. RESULTS Transcriptome analysis of resistant and susceptible strains of this pest species identified a set of differentially expressed genes related to cytochrome P450s, indicating their potential role in resistance to s-methoprene. Laboratory bioassays were performed with s-methoprene treated wheat grains in presence and absence of piperonyl butoxide (PBO), a cytochrome P450 inhibitor. The results indicate that PBO, when applied alone, at least at the concentration tested here, had no effect on R. dominica adult emergence, but has a clear synergistic effect to s-methoprene. The number of produced progeny decreased in presence of the inhibitor, especially in the resistant strain. In addition, we also identified CYP complement (CYPome) of R. dominica, annotated and analysed phylogenetically, to understand the evolutionary relationships with other species. CONCLUSIONS The information generated in current study suggest that PBO can effectively be used to break resistance to s-methoprene in R. dominica.
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Affiliation(s)
- Maria K Sakka
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Phytokou str., 38446, Nea Ionia, Magnesia, Greece.
| | - Maria Riga
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-70013, Heraklion, Crete, Greece
| | - Panagiotis Ioannidis
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-70013, Heraklion, Crete, Greece
| | - Georgia V Baliota
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Phytokou str., 38446, Nea Ionia, Magnesia, Greece
| | - Martha Tselika
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-70013, Heraklion, Crete, Greece.,Department of Biology, University of Crete, 70013, Heraklion, Crete, Greece
| | - Rajeswaran Jagadeesan
- Department of Agriculture and Fisheries, Queensland, Ecosciences Precinct, GPO Box 267, Brisbane, QLD, 4001, Australia
| | - Manoj K Nayak
- Department of Agriculture and Fisheries, Queensland, Ecosciences Precinct, GPO Box 267, Brisbane, QLD, 4001, Australia
| | - John Vontas
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-70013, Heraklion, Crete, Greece.,Laboratory of Pesticide Science, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece
| | - Christos G Athanassiou
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Phytokou str., 38446, Nea Ionia, Magnesia, Greece
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Thornton J, Gomes B, Ayres C, Reimer L. Insecticide resistance selection and reversal in two strains of Aedes aegypti. Wellcome Open Res 2020; 5:183. [PMID: 33521329 PMCID: PMC7814284 DOI: 10.12688/wellcomeopenres.15974.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 01/12/2023] Open
Abstract
Background: Laboratory reared mosquito colonies are essential tools to understand insecticide action. However, they differ considerably from wild populations and from each other depending on their origin and rearing conditions, which makes studying the effects of specific resistance mechanisms difficult. This paper describes our methods for establishing multiple resistant strains of Aedes aegypti from two colonies as a new resource for further research on metabolic and target site resistance. Methods: Two resistant colonies of Ae. aegypti, from Cayman and Recife, were selected through 10 generations of exposure to insecticides including permethrin, malathion and temephos, to yield eight strains with different profiles of resistance due to either target site or metabolic resistance. Resistance ratios for each insecticide were calculated for the selected and unselected strains. The frequency of kdr alleles (F1534C and V1016I) in the Cayman strains was determined using TaqMan assays. A comparative gene expression analysis among Recife strains was conducted using qPCR in larvae (CCae3A, CYP6N12, CYP6F3, CYP9M9) and adults (CCae3A, CYP6N12, CYP6BB2, CYP9J28a). Results: In the selected strain of Cayman, mortality against permethrin reduced almost to 0% and kdr became fixated by 5 generations. A similar phenotype was seen in the unselected homozygous resistant colony, whilst mortality in the susceptible homozygous colony rose to 82.9%. The Recife strains showed different responses between exposure to adulticide and larvicide, with detoxification genes in the temephos selected strain staying similar to the baseline, but a reduction in detoxification genes displayed in the other strains. Conclusions: These selected strains, with a range of insecticide resistance phenotypes and genotypes, will support further research on the effects of target-site and/or metabolic resistance mechanisms on various life-history traits, behaviours and vector competence of this important arbovirus vector.
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Affiliation(s)
- Jonathan Thornton
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
| | - Bruno Gomes
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
- Laboratório de Bioquímica e Fisiologia de Insetos, Oswaldo Cruz Institute (IOC-FIOCRUZ), Rio de Janeiro, 21040-360, Brazil
| | - Constância Ayres
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation (IAM-FIOCRUZ), Recife, Brazil
| | - Lisa Reimer
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
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Meiwald A, Clark E, Kristan M, Edi C, Jeffries CL, Pelloquin B, Irish SR, Walker T, Messenger LA. Reduced long-lasting insecticidal net efficacy and pyrethroid insecticide resistance are associated with over-expression of CYP6P4, CYP6P3 and CYP6Z1 in populations of Anopheles coluzzii from South-East Côte d'Ivoire. J Infect Dis 2020; 225:1424-1434. [PMID: 33175129 PMCID: PMC9016462 DOI: 10.1093/infdis/jiaa699] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/02/2020] [Indexed: 12/14/2022] Open
Abstract
Background Resistance to major public health insecticides in Côte d’Ivoire has intensified and now threatens the long-term effectiveness of malaria vector control interventions. Methods This study evaluated the bioefficacy of conventional and next-generation long-lasting insecticidal nets (LLINs), determined resistance profiles, and characterized molecular and metabolic mechanisms in wild Anopheles coluzzii from Southeast Côte d’Ivoire in 2019. Results Phenotypic resistance was intense: >25% of mosquitoes survived exposure to 10 times the doses of pyrethroids required to kill susceptible populations. Similarly, the 24-hour mortality rate with deltamethrin-only LLINs was very low and not significantly different from that with an untreated net. Sublethal pyrethroid exposure did not induce significant delayed vector mortality effects 72 hours later. In contrast, LLINs containing the synergist piperonyl butoxide, or new insecticides clothianidin and chlorfenapyr, were highly toxic to A. coluzzii. Pyrethroid-susceptible A. coluzzii were significantly more likely to be infected with malaria, compared with those that survived insecticidal exposure. Pyrethroid resistance was associated with significant overexpression of CYP6P4, CYP6P3, and CYP6Z1. Conclusions Study findings raise concerns regarding the operational failure of standard LLINs and support the urgent deployment of vector control interventions incorporating piperonyl butoxide, chlorfenapyr, or clothianidin in areas of high resistance intensity in Côte d’Ivoire.
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Affiliation(s)
- Anne Meiwald
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Emma Clark
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Mojca Kristan
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Constant Edi
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan 01, BP 1303, Abidjan, Côte d'Ivoire
| | - Claire L Jeffries
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Bethanie Pelloquin
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Seth R Irish
- U.S. President's Malaria Initiative and Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Thomas Walker
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Louisa A Messenger
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Vontas J, Katsavou E, Mavridis K. Cytochrome P450-based metabolic insecticide resistance in Anopheles and Aedes mosquito vectors: Muddying the waters. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 170:104666. [PMID: 32980073 DOI: 10.1016/j.pestbp.2020.104666] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Despite the substantial progress achieved in the characterization of cytochrome P450 (CYP) -based resistance mechanisms in mosquitoes, a number of questions remain unanswered. These include: (i) the regulation and physiology of resistance conferring CYPs; (ii) the actual contribution of CYPs in resistance alone or in combination with other detoxification partners or other resistance mechanisms; (iii) the association between overexpression levels and allelic variation, with the catalytic activity and the intensity of resistance and (iv) the true value of molecular diagnostics targeting CYP markers, for driving decision making in the frame of Insecticide Resistance Management applications. Furthermore, the translation of CYP - based insecticide resistance research in mosquitoes into practical applications, is being developed, but it is not fully exploited, as yet. Examples include the production of high throughput platforms for screening the liability (stability) or inhibition potential of novel insecticidal leads and synergists (add-ons), as well as the exploration of the negative cross resistance concept (i.e. detoxification of certain insecticides, but activation of others pro-insecticides). The goal of this review is to critically summarise the current knowledge and the gaps of the CYP-based metabolic insecticide resistance in Anopheles and Aedes mosquito vectors. The progress and limitations of the protein and the reverse/forward genetic approaches, the understanding and importance of molecular and physiological aspects, as well as the current and future exploitation routes of CYP research are discussed.
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Affiliation(s)
- John Vontas
- Foundation for Research and Technology (FORTH), Institute of Molecular Biology and Biotechnology (IMBB), Nikolaou Plastira Street 100, 70013, Heraklion, Crete, Greece; Department of Crop Science, Agricultural University of Athens, Iera Odos 875, 11855, Athens, Greece.
| | - Eva Katsavou
- Department of Crop Science, Agricultural University of Athens, Iera Odos 875, 11855, Athens, Greece
| | - Konstantinos Mavridis
- Foundation for Research and Technology (FORTH), Institute of Molecular Biology and Biotechnology (IMBB), Nikolaou Plastira Street 100, 70013, Heraklion, Crete, Greece
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Lees RS, Ismail HM, Logan RAE, Malone D, Davies R, Anthousi A, Adolfi A, Lycett GJ, Paine MJI. New insecticide screening platforms indicate that Mitochondrial Complex I inhibitors are susceptible to cross-resistance by mosquito P450s that metabolise pyrethroids. Sci Rep 2020; 10:16232. [PMID: 33004954 PMCID: PMC7530702 DOI: 10.1038/s41598-020-73267-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/11/2020] [Indexed: 12/01/2022] Open
Abstract
Fenazaquin, pyridaben, tolfenpyrad and fenpyroximate are Complex I inhibitors offering a new mode of action for insecticidal malaria vector control. However, extended exposure to pyrethroid based products such as long-lasting insecticidal nets (LLINs) has created mosquito populations that are largely pyrethroid-resistant, often with elevated levels of P450s that can metabolise and neutralise diverse substrates. To assess cross-resistance liabilities of the Complex I inhibitors, we profiled their susceptibility to metabolism by P450s associated with pyrethroid resistance in Anopheles gambiae (CYPs 6M2, 6P3, 6P4, 6P5, 9J5, 9K1, 6Z2) and An. funestus (CYP6P9a). All compounds were highly susceptible. Transgenic An. gambiae overexpressing CYP6M2 or CYP6P3 showed reduced mortality when exposed to fenpyroximate and tolfenpyrad. Mortality from fenpyroximate was also reduced in pyrethroid-resistant strains of An. gambiae (VK7 2014 and Tiassalé 13) and An. funestus (FUMOZ-R). P450 inhibitor piperonyl butoxide (PBO) significantly enhanced the efficacy of fenpyroximate and tolfenpyrad, fully restoring mortality in fenpyroximate-exposed FUMOZ-R. Overall, results suggest that in vivo and in vitro assays are a useful guide in the development of new vector control products, and that the Complex I inhibitors tested are susceptible to metabolic cross-resistance and may lack efficacy in controlling pyrethroid resistant mosquitoes.
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Affiliation(s)
- Rosemary S Lees
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Hanafy M Ismail
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Rhiannon A E Logan
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - David Malone
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Rachel Davies
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Amalia Anthousi
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Adriana Adolfi
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Gareth J Lycett
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
| | - Mark J I Paine
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK.
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41
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Oumbouke WA, Pignatelli P, Barreaux AMG, Tia IZ, Koffi AA, Ahoua Alou LP, Sternberg ED, Thomas MB, Weetman D, N'Guessan R. Fine scale spatial investigation of multiple insecticide resistance and underlying target-site and metabolic mechanisms in Anopheles gambiae in central Côte d'Ivoire. Sci Rep 2020; 10:15066. [PMID: 32934291 PMCID: PMC7493912 DOI: 10.1038/s41598-020-71933-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 08/20/2020] [Indexed: 11/10/2022] Open
Abstract
Routine monitoring of occurrence, levels and mechanisms of insecticide resistance informs effective management strategies, and should be used to assess the effect of new tools on resistance. As part of a cluster randomised controlled trial evaluating a novel insecticide-based intervention in central Côte d’Ivoire, we assessed resistance and its underlying mechanisms in Anopheles gambiae populations from a subset of trial villages. Resistance to multiple insecticides in An. gambiae s.s. and An. coluzzii was detected across villages, with dose–response assays demonstrating extremely high resistance intensity to the pyrethroid deltamethrin (> 1,500-fold), and mortality following exposure to pyrethroid-treated bednets was low (< 30% mortality in cone bioassays). The 1014F kdr mutation was almost fixed (≥ 90%) in all villages but the 1575Y kdr-amplifying mutation was relatively rare (< 15%). The carbamate and organophosphate resistance-associated Ace-1 G119S mutation was also detected at moderate frequencies (22–43%). Transcriptome analysis identified overexpression of P450 genes known to confer pyrethroid resistance (Cyp9K1, Cyp6P3, and Cyp6M2), and also a carboxylesterase (COEAE1F) as major candidates. Cyp6P3 expression was high but variable (up to 33-fold) and correlated positively with deltamethrin resistance intensity across villages (r2 = 0.78, P = 0.02). Tools and strategies to mitigate the extreme and multiple resistance provided by these mechanisms are required in this area to avoid future control failures.
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Affiliation(s)
- Welbeck A Oumbouke
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK. .,Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire.
| | - Patricia Pignatelli
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Antoine M G Barreaux
- School of Biological Sciences, University of Bristol, Bristol, UK.,Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Innocent Z Tia
- Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire
| | - Alphonsine A Koffi
- Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire
| | - Ludovic P Ahoua Alou
- Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire
| | - Eleanore D Sternberg
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.,Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Matthew B Thomas
- Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Raphael N'Guessan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.,Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire
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Thornton J, Gomes B, Ayres C, Reimer L. Insecticide resistance selection and reversal in two strains of Aedes aegypti. Wellcome Open Res 2020; 5:183. [PMID: 33521329 PMCID: PMC7814284 DOI: 10.12688/wellcomeopenres.15974.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Laboratory reared mosquito colonies are essential tools to understand insecticide action. However, they differ considerably from wild populations and from each other depending on their origin and rearing conditions, which makes studying the effects of specific resistance mechanisms difficult. This paper describes our methods for establishing multiple resistant strains of Aedes aegypti from two colonies as a new resource for further research on metabolic and target site resistance. Methods: Two resistant colonies of Ae. aegypti, from Cayman and Recife, were selected through 10 generations of exposure to insecticides including permethrin, malathion and temephos, to yield eight strains with different profiles of resistance due to either target site or metabolic resistance. Resistance ratios for each insecticide were calculated for the selected and unselected strains. The frequency of kdr alleles in the Cayman strains was determined using TaqMan assays. A comparative gene expression analysis among Recife strains was conducted using qPCR in larvae (CCae3A, CYP6N12, CYP6F3, CYP9M9) and adults (CCae3A, CYP6N12, CYP6BB2, CYP9J28a). Results: In the selected strain of Cayman, mortality against permethrin reduced almost to 0% and kdr became fixated by 5 generations. A similar phenotype was seen in the unselected homozygous resistant colony, whilst mortality in the susceptible homozygous colony rose to 82.9%. The Recife strains showed different responses between exposure to adulticide and larvicide, with detoxification genes in the temephos selected strain staying similar to the baseline, but a reduction in detoxification genes displayed in the other strains. Conclusions: These selected strains, with a range of insecticide resistance phenotypes and genotypes, will support further research on the effects of target-site and/or metabolic resistance mechanisms on various life-history traits, behaviours and vector competence of this important arbovirus vector.
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Affiliation(s)
- Jonathan Thornton
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
| | - Bruno Gomes
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
- Laboratório de Bioquímica e Fisiologia de Insetos, Oswaldo Cruz Institute (IOC-FIOCRUZ), Rio de Janeiro, 21040-360, Brazil
| | - Constância Ayres
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation (IAM-FIOCRUZ), Recife, Brazil
| | - Lisa Reimer
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, L35QA, UK
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43
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Okumu F. The fabric of life: what if mosquito nets were durable and widely available but insecticide-free? Malar J 2020; 19:260. [PMID: 32690016 PMCID: PMC7370456 DOI: 10.1186/s12936-020-03321-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/04/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Bed nets are the commonest malaria prevention tool and arguably the most cost-effective. Their efficacy is because they prevent mosquito bites (a function of physical durability and integrity), and kill mosquitoes (a function of chemical content and mosquito susceptibility). This essay follows the story of bed nets, insecticides and malaria control, and asks whether the nets must always have insecticides. METHODS Key attributes of untreated or pyrethroid-treated nets are examined alongside observations of their entomological and epidemiological impacts. Arguments for and against adding insecticides to nets are analysed in contexts of pyrethroid resistance, personal-versus-communal protection, outdoor-biting, need for local production and global health policies. FINDINGS Widespread resistance in African malaria vectors has greatly weakened the historical mass mosquitocidal effects of insecticide-treated nets (ITNs), which previously contributed communal benefits to users and non-users. Yet ITNs still achieve substantial epidemiological impact, suggesting that physical integrity, consistent use and population-level coverage are increasingly more important than mosquitocidal properties. Pyrethroid-treatment remains desirable where vectors are sufficiently susceptible, but is no longer universally necessary and should be re-examined alongside other attributes, e.g. durability, coverage, acceptability and access. New ITNs with multiple actives or synergists could provide temporary relief in some settings, but their performance, higher costs, and drawn-out innovation timelines do not justify singular emphasis on insecticides. Similarly, sub-lethal insecticides may remain marginally-impactful by reducing survival of older mosquitoes and disrupting parasite development inside the mosquitoes, but such effects vanish under strong resistance. CONCLUSIONS The public health value of nets is increasingly driven by bite prevention, and decreasingly by lethality to mosquitoes. For context-appropriate solutions, it is necessary to acknowledge and evaluate the potential and cost-effectiveness of durable untreated nets across different settings. Though ~ 90% of malaria burden occurs in Africa, most World Health Organization-prequalified nets are manufactured outside Africa, since many local manufacturers lack capacity to produce the recommended insecticidal nets at competitive scale and pricing. By relaxing conditions for insecticides on nets, it is conceivable that non-insecticidal but durable, and possibly bio-degradable nets, could be readily manufactured locally. This essay aims not to discredit ITNs, but to illustrate how singular focus on insecticides can hinder innovation and sustainability.
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Affiliation(s)
- Fredros Okumu
- Environmental Health & Ecological Sciences, Ifakara Health Institute, Ifakara, Tanzania.
- School of Public Health, University of the Witwatersrand, Johannesburg, Republic of South Africa.
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK.
- School of Life Science and Bioengineering, Nelson Mandela African Institution of Science & Technology, Arusha, Tanzania.
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Brown F, Paton DG, Catteruccia F, Ranson H, Ingham VA. A steroid hormone agonist reduces female fitness in insecticide-resistant Anopheles populations. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 121:103372. [PMID: 32276112 PMCID: PMC10569452 DOI: 10.1016/j.ibmb.2020.103372] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/31/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Insecticide based vector control tools such as insecticide treated bednets and indoor residual spraying represent the cornerstones of malaria control programs. Resistance to chemistries used in these programs is now widespread and represents a significant threat to the gains seen in reducing malaria-related morbidity and mortality. Recently, disruption of the 20-hydroxyecdysone steroid hormone pathway was shown to reduce Plasmodium development and significantly reduce both longevity and egg production in a laboratory susceptible Anopheles gambiae population. Here, we demonstrate that disruption of this pathway by application of the dibenzoylhydrazine, methoxyfenozide (DBH-M), to insecticide resistant An. coluzzii, An. gambiae sl and An. funestus populations significantly reduces egg production in both topical and tarsal application. Moreover, DBH-M reduces adult longevity when applied topically, and tarsally after blood feeding. As the cytochrome p450s elevated in pyrethroid resistant Anopheles only bind DBH-M very weakly, this compound is unlikely to be subject to cross-resistance in a field-based setting. Manipulation of this hormonal signalling pathway therefore represents a potential complementary approach to current malaria control strategies, particularly in areas where high levels of insecticide resistance are compromising existing tools.
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Affiliation(s)
- Faye Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L35QA, UK
| | - Douglas G Paton
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, 655 Huntington Ave, Boston, MA, 02115, USA
| | - Flaminia Catteruccia
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, 655 Huntington Ave, Boston, MA, 02115, USA
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L35QA, UK
| | - Victoria A Ingham
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L35QA, UK.
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45
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Minetti C, Ingham VA, Ranson H. Effects of insecticide resistance and exposure on Plasmodium development in Anopheles mosquitoes. CURRENT OPINION IN INSECT SCIENCE 2020; 39:42-49. [PMID: 32109860 DOI: 10.1016/j.cois.2019.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 05/10/2023]
Abstract
The spread of insecticide resistance in anopheline mosquitoes is a serious threat to the success of malaria control and prospects of elimination, but the potential impact(s) of insecticide resistance or sublethal insecticide exposure on Plasmodium-Anopheles interactions are poorly understood. Only a few studies have attempted to investigate such interactions, despite their clear epidemiological significance for malaria transmission. This short review provides an update on our understanding of the interactions between insecticide resistance and exposure and Plasmodium development, focusing on the mechanisms which might underpin any interactions, and identifying some key knowledge gaps.
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Affiliation(s)
- Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, United Kingdom
| | - Victoria A Ingham
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, United Kingdom
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, United Kingdom.
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46
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Ingham VA, Anthousi A, Douris V, Harding NJ, Lycett G, Morris M, Vontas J, Ranson H. A sensory appendage protein protects malaria vectors from pyrethroids. Nature 2020; 577:376-380. [PMID: 31875852 PMCID: PMC6974402 DOI: 10.1038/s41586-019-1864-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 11/24/2019] [Indexed: 11/15/2022]
Abstract
Pyrethroid-impregnated bed nets have driven considerable reductions in malaria-associated morbidity and mortality in Africa since the beginning of the century1. The intense selection pressure exerted by bed nets has precipitated widespread and escalating resistance to pyrethroids in African Anopheles populations, threatening to reverse the gains that been made by malaria control2. Here we show that expression of a sensory appendage protein (SAP2), which is enriched in the legs, confers pyrethroid resistance to Anopheles gambiae. Expression of SAP2 is increased in insecticide-resistant populations and is further induced after the mosquito comes into contact with pyrethroids. SAP2 silencing fully restores mortality of the mosquitoes, whereas SAP2 overexpression results in increased resistance, probably owing to high-affinity binding of SAP2 to pyrethroid insecticides. Mining of genome sequence data reveals a selective sweep near the SAP2 locus in the mosquito populations of three West African countries (Cameroon, Guinea and Burkina Faso) with the observed increase in haplotype-associated single-nucleotide polymorphisms mirroring the increasing resistance of mosquitoes to pyrethroids reported in Burkina Faso. Our study identifies a previously undescribed mechanism of insecticide resistance that is likely to be highly relevant to malaria control efforts.
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Affiliation(s)
- Victoria A Ingham
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Amalia Anthousi
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Vassilis Douris
- Foundation for Research and Technology - Hellas (FORTH), Institute of Molecular Biology and Biotechnology, Heraklion, Greece
- Department of Biological Applications and Technology, University of Ioannina, Ioannina, Greece
| | | | - Gareth Lycett
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Marion Morris
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - John Vontas
- Foundation for Research and Technology - Hellas (FORTH), Institute of Molecular Biology and Biotechnology, Heraklion, Greece
- Pesticide Science Laboratory, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - Hilary Ranson
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
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Toé KH, Mechan F, Tangena JAA, Morris M, Solino J, Tchicaya EFS, Traoré A, Ismail H, Maas J, Lissenden N, Pinder M, Lindsay SW, Tiono AB, Ranson H, Sagnon N. Assessing the impact of the addition of pyriproxyfen on the durability of permethrin-treated bed nets in Burkina Faso: a compound-randomized controlled trial. Malar J 2019; 18:383. [PMID: 31791332 PMCID: PMC6889366 DOI: 10.1186/s12936-019-3018-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Long-lasting insecticidal nets (LLINs) treated with pyrethroids are the foundation of malaria control in sub-Saharan Africa. Rising pyrethroid resistance in vectors, however, has driven the development of alternative net formulations. Here the durability of polyethylene nets with a novel combination of a pyrethroid, permethrin, and the insect juvenile hormone mimic, pyriproxyfen (PPF), compared to a standard permethrin LLIN, was assessed in rural Burkina Faso. METHODS A compound-randomized controlled trial was completed in two villages. In one village 326 of the PPF-permethrin nets (Olyset Duo) and 327 standard LLINs (Olyset) were distributed to assess bioefficacy. In a second village, 170 PPF-permethrin nets and 376 LLINs were distributed to assess survivorship. Nets were followed at 6-monthly intervals for 3 years. Bioefficacy was assessed by exposing permethrin-susceptible and resistant Anopheles gambiae sensu lato mosquito strains to standard World Health Organization (WHO) cone and tunnel tests with impacts on fertility measured in the resistant strain. Insecticide content was measured using high-performance liquid chromatography. LLIN survivorship was recorded with a questionnaire and assessed by comparing the physical integrity using the proportionate hole index (pHI). RESULTS The PPF-permethrin net met WHO bioefficacy criteria (≥ 80% mortality or ≥ 95% knockdown) for the first 18 months, compared to 6 months for the standard LLIN. Mean mosquito mortality for PPF-permethrin nets, across all time points, was 8.6% (CI 2.6-14.6%) higher than the standard LLIN. Fertility rates were reduced after PPF-permethrin net exposure at 1-month post distribution, but not later. Permethrin content of both types of nets remained within the target range of 20 g/kg ± 25% for 242/248 nets tested. The pyriproxyfen content of PPF-permethrin nets declined by 54%, from 10.4 g/kg (CI 10.2-10.6) to 4.7 g/kg (CI 3.5-6.0, p < 0.001) over 36 months. Net survivorship was poor, with only 13% of PPF-permethrin nets and 12% of LLINs still present in the original household after 36 months. There was no difference in the fabric integrity or survivorship between the two net types. CONCLUSION The PPF-permethrin net, Olyset Duo, met or exceeded the performance of the WHO-recommended standard LLIN (Olyset) in the current study but both net types failed the 3-year WHO bioefficacy criteria.
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Affiliation(s)
- Kobié H Toé
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Frank Mechan
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Marion Morris
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Joanna Solino
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Emile F S Tchicaya
- Swiss Centre for Scientific Research in Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Alphonse Traoré
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Hanafy Ismail
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - James Maas
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Natalie Lissenden
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Margaret Pinder
- Department of Biosciences, Durham University, Durham, UK.,Medical Research Council Unit, The Gambia at the London School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | | | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Hilary Ranson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - N'Falé Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
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Williams J, Flood L, Praulins G, Ingham VA, Morgan J, Lees RS, Ranson H. Characterisation of Anopheles strains used for laboratory screening of new vector control products. Parasit Vectors 2019; 12:522. [PMID: 31690332 PMCID: PMC6833243 DOI: 10.1186/s13071-019-3774-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/25/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Insecticides formulated into products that target Anopheles mosquitos have had an immense impact on reducing malaria cases in Africa. However, resistance to currently used insecticides is spreading rapidly and there is an urgent need for alternative public health insecticides. Potential new insecticides must be screened against a range of characterized mosquito strains to identify potential resistance liabilities. The Liverpool School of Tropical Medicine maintains three susceptible and four resistant Anopheles strains that are widely used for screening for new insecticides. The properties of these strains are described in this paper. METHODS WHO tube susceptibility bioassays were used for colony selection and to screen for resistance to the major classes of public health insecticides. Topical and tarsal contact bioassays were used to produce dose response curves to assess resistance intensity. Bioassays with the synergist piperonyl butoxide were also performed. Taqman™ assays were used to screen for known target site resistance alleles (kdr and ace-1). RT-qPCR was used to quantify expression of genes associated with pyrethroid resistance. RESULTS Pyrethroid selection pressure has maintained resistance to this class in all four resistant strains. Some carbamate and organophosphate resistance has been lost through lack of exposure to these insecticide classes. The Anopheles gambiae (sensu lato) strains, VK7 2014, Banfora M and Tiassalé 13 have higher levels of pyrethroid resistance than the An. funestus FUMOZ-R strain. Elevated expression of P450s is found in all four strains and the 1014F kdr mutation is present in all three An. gambiae strains at varying frequencies. Tarsal contact data and overexpression of CYP4G16 and SAP2 suggest penetration barriers and/or sequestration also confer resistance in Banfora M. CONCLUSIONS Continual selection with deltamethrin has maintained a stable pyrethroid-resistant phenotype over many generations. In conjunction with a standardized rearing regime, this ensures quality control of strains over time allowing for robust product comparison and selection of optimal products for further development. The identification of multiple mechanisms underpinning insecticide resistance highlights the importance of screening new compounds against a range of mosquito strains.
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Affiliation(s)
- Jessica Williams
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Lori Flood
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Giorgio Praulins
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Victoria A. Ingham
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - John Morgan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Rosemary Susan Lees
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Yunta C, Hemmings K, Stevenson B, Koekemoer LL, Matambo T, Pignatelli P, Voice M, Nász S, Paine MJI. Cross-resistance profiles of malaria mosquito P450s associated with pyrethroid resistance against WHO insecticides. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 161:61-67. [PMID: 31685198 DOI: 10.1016/j.pestbp.2019.06.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/20/2019] [Accepted: 06/11/2019] [Indexed: 06/10/2023]
Abstract
Extensive use of pyrethroids for malaria control in Africa has led to widespread pyrethroid resistance in the two major African vectors of malaria An. gambiae and An. funestus. This is often associated with constitutively elevated levels of cytochrome P450s involved with pyrethroid metabolism and detoxification. P450s have the capacity to metabolise diverse substrates, which raises concerns about their potential to cause cross-resistance. A bank of seven recombinant P450s from An. gambiae (CYPs 6M2, 6P2, 6P3, 6P4, 6P5, 9J5) and An. funestus (CYP6P9a) commonly associated with pyrethroid resistance were screened against twelve insecticides representing the five major classes of insecticides recommended by WHO for malaria control; permethrin, etofenprox and bifenthrin (type I pyrethroids), deltamethrin, lambda cyhalothrin and cypermethrin (type II pyrethroids), DDT (organochlorine), bendiocarb (carbamate), malathion, pirimiphos methyl and fenitrothion (organophosphates) and pyriproxyfen (juvenile hormone analogue). DDT was not metabolised by the P450 panel, while bendiocarb was only metabolised by CYP6P3. Pyrethroids and pyriproxyfen were largely susceptible to metabolism by the P450 panel, as were organophosphates, which are activated by P450s. Primiphos-methyl is increasingly used for malaria control. Examination of the pirimiphos-methyl metabolites generated by CYP6P3 revealed both the active pirimiphos-methyl-oxon form and the inactive oxidative cleavage product 2-diethylamino-6-hydroxy-4-methylpyrimidine. The inhibition profile of CYPs 6M2, 6P2, 6P3, 6P9a and 9J5 was also examined using diethoxyfluorescein (DEF) as the probe substrate. Bendiocarb was the weakest inhibitor with IC50 > 100 μM across the P450 panel, while CYP6M2 showed strongest inhibition by malathion (IC50 0.7 μM). The results suggest that P450s present at elevated levels in two major Anopheline vectors of malaria in Africa have the capacity to metabolise a diverse range of pyrethroid and organophosphate insecticides as well as pyriproxyfen that could impact vector control.
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Affiliation(s)
- Cristina Yunta
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Kay Hemmings
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Bradley Stevenson
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Lizette L Koekemoer
- Wits Research Institute for Malaria, MRC Collaborating Centre for Multidisciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Tonderi Matambo
- Wits Research Institute for Malaria, MRC Collaborating Centre for Multidisciplinary Research on Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | | | | | - Szilárd Nász
- Syngenta, Product Metabolism and Analytical Sciences, Jealott's Hill International Research Centre, Bracknell RG42 6EY, UK
| | - Mark J I Paine
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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50
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Dusfour I, Vontas J, David JP, Weetman D, Fonseca DM, Corbel V, Raghavendra K, Coulibaly MB, Martins AJ, Kasai S, Chandre F. Management of insecticide resistance in the major Aedes vectors of arboviruses: Advances and challenges. PLoS Negl Trop Dis 2019; 13:e0007615. [PMID: 31600206 PMCID: PMC6786541 DOI: 10.1371/journal.pntd.0007615] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The landscape of mosquito-borne disease risk has changed dramatically in recent decades, due to the emergence and reemergence of urban transmission cycles driven by invasive Aedes aegypti and Ae. albopictus. Insecticide resistance is already widespread in the yellow fever mosquito, Ae. Aegypti; is emerging in the Asian tiger mosquito Ae. Albopictus; and is now threatening the global fight against human arboviral diseases such as dengue, yellow fever, chikungunya, and Zika. Because the panel of insecticides available for public health is limited, it is of primary importance to preserve the efficacy of existing and upcoming active ingredients. Timely implementation of insecticide resistance management (IRM) is crucial to maintain the arsenal of effective public health insecticides and sustain arbovirus vector control. METHODOLOGY AND PRINCIPAL FINDINGS This Review is one of a series being generated by the Worldwide Insecticide resistance Network (WIN) and aims at defining the principles and concepts underlying IRM, identifying the main factors affecting the evolution of resistance, and evaluating the value of existing tools for resistance monitoring. Based on the lessons taken from resistance strategies used for other vector species and agricultural pests, we propose a framework for the implementation of IRM strategies for Aedes mosquito vectors. CONCLUSIONS AND SIGNIFICANCE Although IRM should be a fixture of all vector control programs, it is currently often absent from the strategic plans to control mosquito-borne diseases, especially arboviruses. Experiences from other public health disease vectors and agricultural pests underscore the need for urgent action in implementing IRM for invasive Aedes mosquitoes. Based on a plan developed for malaria vectors, here we propose some key activities to establish a global plan for IRM in Aedes spp.
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Affiliation(s)
- Isabelle Dusfour
- Laboratoire d’Entomologie Médicale, Institut Pasteur de la Guyane, Cayenne, French Guiana, France
| | - John Vontas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas (FORTH), Heraklion, Crete, Greece
- Pesticide Science Laboratory, Agricultural University of Athens, Athens, Greece
| | - Jean-Philippe David
- Laboratoire d’Ecologie Alpine (LECA), Centre National de la Recherche Scientifique (CNRS), Université Grenoble-Alpes, Grenoble, France
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Dina M. Fonseca
- Center for Vector Biology, Rutgers University (RU), New Brunswick, New Jersey, United States of America
| | - Vincent Corbel
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement, IRD, CNRS, University of Montpellier, Montpellier, France
| | - Kamaraju Raghavendra
- Department of Health Research, National Institute of Malaria Research, Dwarka, Delhi, India
| | - Mamadou B. Coulibaly
- Malaria Research and Training Center (MRTC), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Ademir J. Martins
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Shinji Kasai
- Laboratory of Pesticide Science, Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Fabrice Chandre
- Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Institut de Recherche pour le Développement, IRD, CNRS, University of Montpellier, Montpellier, France
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