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Mandodan S, Gangmei K, Vijayakumar A, Kunnikuruvan A, Lukose J, Padmanaban H, Bora B, Ashokkumar M, Irudayaraj G, Subbiah P. Molecular identification and GC-MS analysis of a newly isolated novel bacterium (Lysinibacillus sp. VCRC B655) for mosquito control. Mol Biol Rep 2024; 51:800. [PMID: 39001994 DOI: 10.1007/s11033-024-09734-9] [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: 05/07/2024] [Accepted: 06/17/2024] [Indexed: 07/15/2024]
Abstract
BACKGROUND Mosquitoes are widespread globally and have contributed to transmitting pathogens to humans and the burden of vector-borne diseases. They are effectively controlled at their larval stages by biocontrol agents. Unravelling natural sources for microbial agents can lead us to novel potential candidates for managing mosquito-borne diseases. In the present study, an attempt was made to isolate a novel bacterium from the field-collected agricultural soil for larvicidal activity and promising bacterial metabolites for human healthcare. METHODS AND RESULTS Field-collected soil samples from the Union territory of Puducherry, India, have been used as the source of bacteria. Isolate VCRC B655 belonging to the genus Lysinibacillus was identified by 16S rRNA gene sequencing and exhibited promising larvicidal activity against different mosquito species, including Culex (Cx.) quinquefasciatus, Anopheles (An.) stephensi, and Aedes (Ae.) aegypti. The lethal concentration (LC) of Lysinibacillus sp. VCRCB655 was observed to be high for Cx. quiquefasciatus: LC50 at 0.047 mg/l, LC90 at 0.086 mg/l, followed by An. stephensi and Ae. aegypti (LC50: 0.6952 mg/l and 0.795 mg/l) respectively. Additionally, metabolic profiling of the culture supernatant was carried out through Gas chromatography and Mass spectrophotometry (GC/MS) and identified 15 major secondary metabolites of different metabolic classes. Diketopiperazine (DKPs), notably pyro lo [1, 2-a] pyrazine1, 4-dione, are the abundant compounds reported for antioxidant activity, and an insecticide compound benzeneacetic acid was also identified. CONCLUSIONS A new bacterial isolate, Lysinibacillus sp. VCRC B655 has been identified with significant larvicidal activity against mosquito larvae with no observed in non-target organisms. GC-MS analysis revealed diverse bioactive compounds with substantial biological applications. In conclusion, Lysinibacillus sp. VCRC B655 showed promise as an alternative biocontrol agent for mosquito vector control, with additional biological applications further enhancing its significance.
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Affiliation(s)
- Sahadiya Mandodan
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Kakhuangailiu Gangmei
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Abhisubesh Vijayakumar
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Aneha Kunnikuruvan
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Jibi Lukose
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Hemaladkshmi Padmanaban
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Bhagyashree Bora
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Mathivanan Ashokkumar
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Geetha Irudayaraj
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India
| | - Poopathi Subbiah
- Unit of Microbiology and Immunology (UMI), Department of Health Research (Ministry of Health & Family Welfare, Govt. of India), ICMR-Vector Control Research Centre (VCRC), Medical Complex Indira Nagar, Puducherry, 605006, India.
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Kolbenschlag S, Pietz S, Röder N, Schwenk K, Bundschuh M. Phenotypic adaptation of Chironomus riparius to chronic Bti exposure: effects on emergence time and nutrient content. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 273:107013. [PMID: 38996481 DOI: 10.1016/j.aquatox.2024.107013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/27/2024] [Accepted: 06/26/2024] [Indexed: 07/14/2024]
Abstract
Insects with aquatic larval and terrestrial adult life stages are a key component of coupled aquatic-terrestrial ecosystems. Thus, stressors applied to water bodies adversely affecting those larvae have the potential to influence the riparian zone through altered emergence, with differences in prey availability, timing, or nutrition. In this study, the common model organism Chironomus riparius, a species of Chironomidae (Diptera), was used. This selection was further motivated by its wide distribution in European freshwaters and its importance as prey for terrestrial predators. A stressor of high importance in this context is the globally used mosquito control agent Bacillus thuringiensis var. israelensis (Bti) which has been shown to affect Chironomidae. Here, we investigated the ability of chironomid populations to adapt to a regularly applied stressor, leading to a reduced impact of Bti. Therefore, the initial sensitivity of laboratory populations of C. riparius was investigated under the influence of field-relevant Bti treatments (three doses × two application days) and different food sources (high-quality TetraMin vs. low-quality Spirulina). Following a chronic exposure to Bti over six months, the sensitivity of pre-exposed and naïve populations was re-evaluated. Food quality had a strong impact on emergence timing and nutrient content. In addition, alterations in emergence time as well as protein and lipid contents of chronically exposed populations indicated a selection for individuals of advantageous energetics, potentially leading to a more efficient development while combating Bti. Signs of adaptation could be confirmed in five out of 36 tested scenarios suggesting adaptation to Bti at the population level. Adaptive responses of one or several species could theoretically (via eco-evolutionary dynamics) result in a community shift, favouring the prevalence of Bti-tolerant species. (In)direct effects of Bti and the adaptive responses at both population and community levels could affect higher trophic levels and may determine the fate of meta-ecosystems.
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Affiliation(s)
- Sara Kolbenschlag
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Sebastian Pietz
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Nina Röder
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Klaus Schwenk
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Mirco Bundschuh
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, SWE-75007 Uppsala, Sweden.
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Pacheco S, Gallegos AS, Peláez-Aguilar ÁE, Sánchez J, Gómez I, Soberón M, Bravo A. CRISPR-Cas9 knockout of membrane-bound alkaline phosphatase or cadherin does not confer resistance to Cry toxins in Aedes aegypti. PLoS Negl Trop Dis 2024; 18:e0012256. [PMID: 38870209 PMCID: PMC11207138 DOI: 10.1371/journal.pntd.0012256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/26/2024] [Accepted: 05/30/2024] [Indexed: 06/15/2024] Open
Abstract
The Aedes aegypti cadherin-like protein (Aae-Cad) and the membrane-bound alkaline phosphatase (Aae-mALP) are membrane proteins identified as putative receptors for the larvicidal Cry toxins produced by Bacillus thuringiensis subsp. israelensis bacteria. Cry toxins are the most used toxins in the control of different agricultural pest and mosquitos. Despite the relevance of Aae-Cad and Aae-mALP as possible toxin-receptors in mosquitoes, previous efforts to establish a clear functional connection among them and Cry toxins activity have been relatively limited. In this study, we used CRISPR-Cas9 to generate knockout (KO) mutations of Aae-Cad and Aae-mALP. The Aae-mALP KO was successfully generated, in contrast to the Aae-Cad KO which was obtained only in females. The female-linked genotype was due to the proximity of aae-cad gene to the sex-determining loci (M:m). Both A. aegypti KO mutant populations were viable and their insect-development was not affected, although a tendency on lower egg hatching rate was observed. Bioassays were performed to assess the effects of these KO mutations on the susceptibility of A. aegypti to Cry toxins, showing that the Aae-Cad female KO or Aae-mALP KO mutations did not significantly alter the susceptibility of A. aegypti larvae to the mosquitocidal Cry toxins, including Cry11Aa, Cry11Ba, Cry4Ba, and Cry4Aa. These findings suggest that besides the potential participation of Aae-Cad and Aae-mALP as Cry toxin receptors in A. aegypti, additional midgut membrane proteins are involved in the mode of action of these insecticidal toxins.
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Affiliation(s)
- Sabino Pacheco
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Adrián S. Gallegos
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Ángel E. Peláez-Aguilar
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Jorge Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Isabel Gómez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Mario Soberón
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Alejandra Bravo
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
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Unlu I, Buckner EA, Medina J, Vasquez C, Cabrera A, Romero-Weaver AL, Ramirez D, Kendziorski NL, Kosinski KJ, Fedirko TJ, Ketelsen L, Dorsainvil C, Estep AS. Insecticide resistance of Miami-Dade Culex quinquefasciatus populations and initial field efficacy of a new resistance-breaking adulticide formulation. PLoS One 2024; 19:e0296046. [PMID: 38346028 PMCID: PMC10861066 DOI: 10.1371/journal.pone.0296046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/05/2023] [Indexed: 02/15/2024] Open
Abstract
Sporadic outbreaks of human cases of West Nile virus (WNV), primarily vectored by Culex quinquefasciatus Say in suburban and urban areas, have been reported since introduction of the virus into Florida in 2001. Miami-Dade County, Florida is part of one of the largest metropolitan areas in the United States, supports Cx. quinquefasciatus year-round, and recently experienced over 60 human cases of WNV during one outbreak. To facilitate more effective integrated vector management and public health protection, we used the Centers for Disease Control and Prevention (CDC) bottle bioassay method to evaluate the susceptibility of adult Cx. quinquefasciatus collected from 29 locations throughout Miami-Dade County to pyrethroid and organophosphate adulticide active ingredients (AIs) used by Miami-Dade County Mosquito Control. We also determined the frequency of the 1014 knockdown resistance (kdr) mutation for Cx. quinquefasciatus from a subset of 17 locations. We detected resistance to two pyrethroid AIs in all tested locations (permethrin: 27 locations, deltamethrin: 28 locations). The 1014F allele was widely distributed throughout all 17 locations sampled; however, 29.4% of these locations lacked 1014F homozygotes even though phenotypic pyrethroid resistance was present. Organophosphate resistance was more variable; 20.7% of the locations tested were susceptible to malathion, and 33.3% of the populations were susceptible to naled. We subsequently conducted a field trial of ReMoa Tri, a recently approved multiple AI adulticide formulation labelled for resistant mosquitoes, against a mixed location field population of Miami-Dade Cx. quinquefasciatus. Average 24-hr mortality was 65.1 ± 7.2% and 48-hr mortality increased to 85.3 ± 9.1%, indicating good control of these resistant Cx. quinquefasciatus. This current study shows that insecticide resistance is common in local Cx. quinquefasciatus but effective options are available to maintain control during active disease transmission in Miami-Dade County.
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Affiliation(s)
- Isik Unlu
- Miami-Dade County Mosquito Control Division, Miami, Florida, United States of America
| | - Eva A. Buckner
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Johanna Medina
- Miami-Dade County Mosquito Control Division, Miami, Florida, United States of America
| | - Chalmers Vasquez
- Miami-Dade County Mosquito Control Division, Miami, Florida, United States of America
| | - Aimee Cabrera
- Miami-Dade County Mosquito Control Division, Miami, Florida, United States of America
| | - Ana L. Romero-Weaver
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Daviela Ramirez
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Natalie L. Kendziorski
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Kyle J. Kosinski
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - T. J. Fedirko
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Leigh Ketelsen
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Chelsea Dorsainvil
- Department of Entomology and Nematology, Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, Florida, United States of America
| | - Alden S. Estep
- Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, Florida, United States of America
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Anwar S, Ahmed B, Qadir MI. Arboviruses: Transmission and Host Resistance. Crit Rev Eukaryot Gene Expr 2024; 34:15-31. [PMID: 38073439 DOI: 10.1615/critreveukaryotgeneexpr.2023049820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
In this review, there is a complete description of the classes of arboviruses, their evolutionary process, virus characterization, disease transmission methods; it also describes about the vectors involved in transmission and their mood of transmission, both biologically as well as non-biologically and, about host, the resistance mechanism in host, and artificial methods of preventing those viral transmissions. Arboviruses transmitted to hosts by some vectors such as mosquitoes, ticks, etc. The virus replicates in the host can be prevented by some host resistance mechanisms like RNA interference (RNAi), which degrade virus RNA by its antiviral activity, insect repellents, IGRs, and PI technology.
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Affiliation(s)
- Sidra Anwar
- Institute of Molecular Biology and Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Bilal Ahmed
- University of Science And Technology of Fujairah, UAE; School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Muhammad Imran Qadir
- Institute of Molecular Biology & Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
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Thierry DN, Djamouko-Djonkam L, Gisèle FD, Audrey MMP, Timoléon T, Serge Hubert ZT, Sinclair WC, Christophe AN. Assessment of the impact of the biological larvicide VectoMax G: Combination of Bacillus thuringiensis and Lysinibacillus sphaericus on non-target aquatic organisms in Yaoundé-Cameroon. Heliyon 2023; 9:e17723. [PMID: 37533979 PMCID: PMC10391952 DOI: 10.1016/j.heliyon.2023.e17723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 08/04/2023] Open
Abstract
There has been a renewed interest for larviciding during the recent decade. Although biological larvicides are considered not to be harmful to non-target organisms, there is still not sufficient data on the effect of new long-lasting larvicide formulations such as VectoMax G combining Bacillus thuringiensis israelensis and Lysinibacullus sphaericus on the environment especially on non-target organisms. The present study aimed to assess the possible influence of VectoMax G on the diversity and abundance of the aquatic fauna cohabiting with mosquito larvae in breeding habitats during a larviciding trial in the city of Yaoundé. Twelve districts of the city of Yaoundé divided into 6 intervention and 6 control sites were chosen for the study. In each district 4 semi-permanent or permanent aquatic habitats were followed. VectoMax G application was done once every two weeks during 6 months and aquatic organisms were collected 48 h after each treatment. All collected organisms were brought to the laboratory for identification. Physico-chemical parameters were recorded as well. A high diversity of the zooplankton was recorded in the intervention areas with 28 species collected against 14 species in the control areas. Cladocerans were the most represented group in both sites while Ostracods were found only in control sites. A total of 19 macro-invertebrates species were recorded in the control areas vs 16 species in the intervention areas. Gasteropods were the most represented groups of macro-invertebrates. Vertebrates such as larvivorous fishes and amphibians larvae were also found in approximately similar densities in both sites. The study indicated no significant influence of larviciding with VectoMax G on the diversity and abundance of the non-target aquatic fauna in the city of Yaoundé.
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Affiliation(s)
- Djepand-Ngognouak Thierry
- Malaria Research Laboratory, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Landre Djamouko-Djonkam
- Malaria Research Laboratory, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Foko Dadji Gisèle
- Laboratory of Zoology, Higher Teacher Training College, University of Yaoundé I, P.O. Box 47, Yaoundé, Cameroon
| | - Mayi Marie Paul Audrey
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Tchuinkam Timoléon
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | | | - Wondji Charles Sinclair
- Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
- Centre for Research in Infectious Disease (CRID), Yaoundé, P.O. Box 13591, Cameroon
| | - Antonio-Nkondjio Christophe
- Malaria Research Laboratory, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
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Bacillus thuringiensis Cyt Proteins as Enablers of Activity of Cry and Tpp Toxins against Aedes albopictus. Toxins (Basel) 2023; 15:toxins15030211. [PMID: 36977103 PMCID: PMC10054650 DOI: 10.3390/toxins15030211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/27/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Aedes albopictus is a species of mosquito, originally from Southeast Asia, that belongs to the Culicidae family and the Dipteran insect order. The distribution of this vector has rapidly changed over the past decade, making most of the temperate territories in the world vulnerable to important human vector-borne diseases such as dengue, yellow fever, zika or chikungunya. Bacillus thuringiensis var. israeliensis (Bti)-based insecticides represent a realistic alternative to the most common synthetic insecticides for the control of mosquito larvae. However, several studies have revealed emerging resistances to the major Bti Crystal proteins such as Cry4Aa, Cry4Ba and Cry11Aa, making the finding of new toxins necessary to diminish the exposure to the same toxicity factors overtime. Here, we characterized the individual activity of Cyt1Aa, Cry4Aa, Cry4Ba and Cry11Aa against A. albopictus and found a new protein, Cyt1A-like, that increases the activity of Cry11Aa more than 20-fold. Additionally, we demonstrated that Cyt1A-like facilitates the activity three new Bti toxins: Cry53-like, Cry56A-like and Tpp36-like. All in all, these results provide alternatives to the currently available Bti products for the control of mosquito populations and position Cyt proteins as enablers of activity for otherwise non-active crystal proteins.
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Fei X, Xiao S, Huang X, Li Z, Li X, He C, Li Y, Zhang X, Deng X. Control of Aedes mosquito populations using recombinant microalgae expressing short hairpin RNAs and their effect on plankton. PLoS Negl Trop Dis 2023; 17:e0011109. [PMID: 36701378 PMCID: PMC9904476 DOI: 10.1371/journal.pntd.0011109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 02/07/2023] [Accepted: 01/17/2023] [Indexed: 01/27/2023] Open
Abstract
New biocontrol strategies are urgently needed to combat vector-borne infectious diseases. This study presents a low-cost method to produce a potential mosquito insecticide that utilizes the microalgae released into suburban water sources to control mosquito populations. Chlorella microalgae are ubiquitous in local waters, which were chosen as the host for genetic transfection. This species facilitated the recombinant algae to adapt to the prevailing environmental conditions with rapid growth and high relative abundance. The procedure involved microalgae RNAi-based insecticides developed using short hairpin RNAs targeting the Aedes aegypti chitin synthase A (chsa) gene in Chlorella. These insecticides effectively silenced the chsa gene, inhibiting Aedes metamorphosis in the laboratory and simulated-field trials. This study explored the impact of recombinant microalgae on the phytoplankton and zooplankton in suburban waters. High-throughput sequencing revealed that rapid reproduction of recombinant Chlorella indirectly caused the disappearance of some phytoplankton and reduced the protozoan species. This study demonstrated that a recombinant microalgae-based insecticide could effectively reduce the population of Aedes mosquitoes in the laboratory and simulated field trials. However, the impact of this technology on the environment and ecology requires further investigation.
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Affiliation(s)
- Xiaowen Fei
- Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Sha Xiao
- Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Xiaodan Huang
- Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Zhijie Li
- Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Xinghan Li
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science & Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China
| | - Changhao He
- Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Yajun Li
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science & Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China
- Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, China
| | - Xiuxia Zhang
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science & Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China
- Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, China
| | - Xiaodong Deng
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science & Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China
- Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Haikou, China
- Zhanjiang Experimental Station, CATAS, Zhanjiang, China
- * E-mail:
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Fei X, Huang X, Li Z, Li X, He C, Xiao S, Li Y, Zhang X, Deng X. Effect of marker-free transgenic Chlamydomonas on the control of Aedes mosquito population and on plankton. Parasit Vectors 2023; 16:18. [PMID: 36653886 PMCID: PMC9847121 DOI: 10.1186/s13071-022-05647-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/29/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND More than half of the world's population suffers from epidemic diseases that are spread by mosquitoes. The primary strategy used to stop the spread of mosquito-borne diseases is vector control. Interference RNA (RNAi) is a powerful tool for controlling insect populations and may be less susceptible to insect resistance than other strategies. However, public concerns have been raised because of the transfer of antibiotic resistance marker genes to environmental microorganisms after integration into the recipient genome, thus allowing the pathogen to acquire resistance. Therefore, in the present study, we modified the 3-hydroxykynurenine transaminase (3hkt) and hormone receptor 3 (hr3) RNAi vectors to remove antibiotic resistance marker genes and retain the expression cassette of the inverse repeat sequence of the 3hkt/hr3 target gene. This recombinant microalgal marker-free RNAi insecticide was subsequently added to the suburban water in a simulated-field trial to test its ability to control mosquito population. METHODS The expression cassette of the 3hkt/hr3 inverted repeat sequence and a DNA fragment of the argininosuccinate lyase gene without the ampicillin resistance gene were obtained using restriction enzyme digestion and recovery. After the cotransformation of Chlamydomonas, the recombinant algae was then employed to feed Aedes albopictus larvae. Ten and 300 larvae were used in small- and large-scale laboratory Ae.albopictus feeding trials, respectively. Simulated field trials were conducted using Meishe River water that was complemented with recombinant Chlamydomonas. Moreover, the impact of recombinant microalgae on phytoplankton and zooplankton in the released water was explored via high-throughput sequencing. RESULTS The marker-free RNAi-recombinant Chlamydomonas effectively silenced the 3hkt/hr3 target gene, resulting in the inhibition of Ae. albopictus development and also in the high rate of Ae. albopictus larvae mortality in the laboratory and simulated field trials. In addition, the results confirmed that the effect of recombinant Chlamydomonas on plankton in the released water was similar to that of the nontransgenic Chlamydomonas, which could reduce the abundance and species of plankton. CONCLUSIONS The marker-free RNAi-recombinant Chlamydomonas are highly lethal to the Ae. albopictus mosquito, and their effect on plankton in released water is similar to that of the nontransgenic algal strains, which reduces the abundance and species of plankton. Thus, marker-free recombinant Chlamydomonas can be used for mosquito biorational control and mosquito-borne disease prevention.
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Affiliation(s)
- Xiaowen Fei
- grid.443397.e0000 0004 0368 7493Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Xiaodan Huang
- grid.443397.e0000 0004 0368 7493Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Zhijie Li
- grid.443397.e0000 0004 0368 7493Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Xinghan Li
- grid.509158.0Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science and Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China
| | - Changhao He
- grid.443397.e0000 0004 0368 7493Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Sha Xiao
- grid.443397.e0000 0004 0368 7493Department of Biochemistry and Molecular Biology, Hainan Medical University, Haikou, China
| | - Yajun Li
- grid.509158.0Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science and Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China ,Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou, China
| | - Xiuxia Zhang
- grid.509158.0Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science and Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China ,Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou, China
| | - Xiaodong Deng
- grid.509158.0Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science and Key Laboratory of Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute for Tropical Agricultural Resources, Haikou, China ,Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-Resources, Haikou, China ,grid.453499.60000 0000 9835 1415Zhanjiang Experimental Station, CATAS, Zhanjiang, China
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10
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Meier CJ, Rouhier MF, Hillyer JF. Chemical Control of Mosquitoes and the Pesticide Treadmill: A Case for Photosensitive Insecticides as Larvicides. INSECTS 2022; 13:1093. [PMID: 36555003 PMCID: PMC9783766 DOI: 10.3390/insects13121093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Insecticides reduce the spread of mosquito-borne disease. Over the past century, mosquito control has mostly relied on neurotoxic chemicals-such as pyrethroids, neonicotinoids, chlorinated hydrocarbons, carbamates and organophosphates-that target adults. However, their persistent use has selected for insecticide resistance. This has led to the application of progressively higher amounts of insecticides-known as the pesticide treadmill-and negative consequences for ecosystems. Comparatively less attention has been paid to larvae, even though larval death eliminates a mosquito's potential to transmit disease and reproduce. Larvae have been targeted by source reduction, biological control, growth regulators and neurotoxins, but hurdles remain. Here, we review methods of mosquito control and argue that photoactive molecules that target larvae-called photosensitive insecticides or PSIs-are an environmentally friendly addition to our mosquitocidal arsenal. PSIs are ingested by larvae and produce reactive oxygen species (ROS) when activated by light. ROS then damage macromolecules resulting in larval death. PSIs are degraded by light, eliminating environmental accumulation. Moreover, PSIs only harm small translucent organisms, and their broad mechanism of action that relies on oxidative damage means that resistance is less likely to evolve. Therefore, PSIs are a promising alternative for controlling mosquitoes in an environmentally sustainable manner.
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Affiliation(s)
- Cole J. Meier
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | | | - Julián F. Hillyer
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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11
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Poulin B, Lefebvre G, Hilaire S, Després L. Long-term persistence and recycling of Bacillus thuringiensis israelensis spores in wetlands sprayed for mosquito control. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 243:114004. [PMID: 36007317 DOI: 10.1016/j.ecoenv.2022.114004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) is the main larvicide used to control mosquitoes worldwide. Although there is accumulating evidence of Bti having environmental effects on non-target fauna, relatively few field studies have documented the fate of Bti spores in the environment. Spore density was quantified over a 6-yr period (2012-2017) in Mediterranean marshes sprayed with Vectobac 12AS (32 ITU/ha) since 2006 to reduce the nuisance caused by Aedes caspius. Bti spores were naturally found in all habitat types. Spore density expressed as colony-forming units per gram of soil (CFU g-1) increased significantly at treated sites by a factor of 22 to 500 times relative to control sites, with mean values of 7730 CFU g-1 in halophilous scrubs, 38,000 in reed beds, 49,000 in bulrush beds and 50 000 in rush beds. Spore density varied little in the first months after the spraying season (April-October), but increased sharply in spring, just before the annual launch of mosquito control. Considering that Bti is an insect pathogen that cannot proliferate without a suitable insect host, this unexpected recrudescence in spring could be related to the warming of water that triggers activity and development of benthic organisms such as chironomids, which may contribute to Bti proliferation by ingesting accumulated spores at the surface of sediments. While spore density tends to decrease over time, presumably during the summer period as a result of increased UV exposure, three to four years were necessary for spore density to return to normal levels after mosquito-control interruption. This study is important because it demonstrates that environmental effects of mosquito-control using Bti can far exceed the short period of Bti efficacy against lentic mosquitoes. Considering that Bti is a microbial agent, these long-term effects should be addressed at multiple levels of ecosystem organization from a one-health perspective.
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Affiliation(s)
- Brigitte Poulin
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Gaëtan Lefebvre
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Samuel Hilaire
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Laurence Després
- Univ. Grenoble-Alpes, Univ. Savoie Mont Blanc, CNRS, Laboratoire d'Ecologie Alpine, 38000 Grenoble, France.
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12
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Andreazza F, Oliveira EE, Martins GF. Implications of Sublethal Insecticide Exposure and the Development of Resistance on Mosquito Physiology, Behavior, and Pathogen Transmission. INSECTS 2021; 12:insects12100917. [PMID: 34680686 PMCID: PMC8539869 DOI: 10.3390/insects12100917] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/03/2021] [Accepted: 10/04/2021] [Indexed: 12/31/2022]
Abstract
Simple Summary Mosquitoes are one of the greatest threats to human lives; they transmit a wide range of pathogens, including viruses that cause lethal diseases. Mosquitoes are found in both aquatic (as larvae or pupae) and terrestrial (as adults) environments during their complex life cycle. For decades, insecticides have been systematically used on mosquitoes with the aim to reduce their population. Little is known about how the stress resulting from the exposure of mosquitoes to insecticides impacts the tri-partite relationship between the mosquitoes, their vertebrate hosts, and the pathogens they transmit. In this work, we review existing experimental evidence to obtain a broad picture on the potential effects of the (sub)lethal exposure of hematophagous mosquitoes to different insecticides. We have focused on studies that have advanced our understanding of their physiological and behavioral responses (including the mechanisms behind insecticide resistance) and the spread of pathogens by these vectors—understudied but critically important issues for epidemiology. Studying these exposure-related effects is of paramount importance for predicting how they respond to insecticide exposure and whether this exposure makes them more or less likely to transmit pathogens. Abstract For many decades, insecticides have been used to control mosquito populations in their larval and adult stages. Although changes in the population genetics, physiology, and behavior of mosquitoes exposed to lethal and sublethal doses of insecticides are expected, the relationships between these changes and their abilities to transmit pathogens remain unclear. Thus, we conducted a comprehensive review on the sublethal effects of insecticides and their contributions to insecticide resistance in mosquitoes, with the main focus on pyrethroids. We discuss the direct and acute effects of sublethal concentrations on individuals and populations, the changes in population genetics caused by the selection for resistance after insecticide exposure, and the major mechanisms underlying such resistance. Sublethal exposures negatively impact the individual’s performance by affecting their physiology and behavior and leaving them at a disadvantage when compared to unexposed organisms. How these sublethal effects could change mosquito population sizes and diversity so that pathogen transmission risks can be affected is less clear. Furthermore, despite the beneficial and acute aspects of lethality, exposure to higher insecticide concentrations clearly impacts the population genetics by selecting resistant individuals, which may bring further and complex interactions for mosquitoes, vertebrate hosts, and pathogens. Finally, we raise several hypotheses concerning how the here revised impacts of insecticides on mosquitoes could interplay with vector-mediated pathogens’ transmission.
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Affiliation(s)
- Felipe Andreazza
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (F.A.); (E.E.O.)
| | - Eugênio E. Oliveira
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil; (F.A.); (E.E.O.)
| | - Gustavo Ferreira Martins
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil
- Correspondence:
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13
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Carvalho KDS, Guedes DRD, Crespo MM, de Melo-Santos MAV, Silva-Filha MHNL. Aedes aegypti continuously exposed to Bacillus thuringiensis svar. israelensis does not exhibit changes in life traits but displays increased susceptibility for Zika virus. Parasit Vectors 2021; 14:379. [PMID: 34321098 PMCID: PMC8317411 DOI: 10.1186/s13071-021-04880-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/16/2021] [Indexed: 11/20/2022] Open
Abstract
Background Aedes aegypti can transmit arboviruses worldwide, and Bacillus thuringiensis svar. israelensis (Bti)-based larvicides represent an effective tool for controlling this species. The safety of Bti and lack of resistance have been widely reported; however, little is known regarding the impact of the extensive use of these larvicides on the life traits of mosquitoes. Therefore, this study investigated biological parameters, including susceptibility to arbovirus, of an Ae. aegypti strain (RecBti) subjected to 29 generations of exposure to Bti compared with the RecL reference strain. Methods The biological parameters of individuals reared under controlled conditions were compared. Also, the viral susceptibility of females not exposed to Bti during their larval stage was analysed by oral infection and followed until 14 or 21 days post-infection (dpi). Results RecBti individuals did not display alterations in the traits that were assessed (fecundity, fertility, pupal weight, developmental time, emergence rate, sex ratio and haematophagic capacity) compared to RecL individuals. Females from both strains were susceptible to dengue serotype 2 (DENV-2) and Zika virus (ZIKV). However, RecBti females showed significantly higher rates of ZIKV infection compared with RecL females at 7 (90% versus 68%, Chi-square: χ2 = 7.27, df = 1, P = 0.006) and 14 dpi (100% versus 87%, Chi-square: χ2 = 7.69, df = 1, P = 0.005) and for dissemination at 7 dpi (83.3% versus 36%, Fisher’s exact test: P < 0.0001, OR = 0.11, 95% CI 0.03–0.32). Quantification of DENV-2 and ZIKV viral particles produced statistically similar results for females from both strains. Conclusions Prolonged exposure of Ae. aegypti larvae to Bti did not alter most of the evaluated biological parameters, except that RecBti females exhibited a higher vector susceptibility for ZIKV. This finding is related to a background of Bti exposure for several generations but not to a previous exposure of the tested females during the larval stage. This study highlights mosquito responses that could be associated with the chronic exposure to Bti in addition to the primary larvicidal effect elicited by this control agent. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04880-6.
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Affiliation(s)
| | | | - Mônica Maria Crespo
- Department of Entomology, Instituto Aggeu Magalhães-Fiocruz, Recife, Pernambuco, Brazil
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14
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Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance. Toxins (Basel) 2021; 13:toxins13080523. [PMID: 34437394 PMCID: PMC8402332 DOI: 10.3390/toxins13080523] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022] Open
Abstract
Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.
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15
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Weeks ENI, Kroll KJ, Johnson TS, Colquhoun T, Cuda JP, Denslow ND, Stevens BR. Novel effective mosquito larvicide DL-methionine: Lack of toxicity to non-target aquatic organisms. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 213:112013. [PMID: 33601173 DOI: 10.1016/j.ecoenv.2021.112013] [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: 11/19/2020] [Revised: 01/18/2021] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
Mosquito larvicides are an effective tool for reducing numbers of adult females that bite and potentially spread pathogenic organisms. Methionine, an essential amino acid in humans, has been previously demonstrated to be a highly effective larvicide against four (4) mosquito species in three (3) genera, Anopheles, Culex and Aedes. The aim of the present study was to determine the potential impact on non-target aquatic organisms of methionine applied as a mosquito larvicide. DL-methionine concentrations ranging from 0.06% to 1.00% were used; wherein the highest concentration of 1.00% would result in 100% mortality within 48 h in mosquitoes. Acute toxicity assays were conducted in accordance with the US Environmental Protection Agency (US EPA) guidelines for the water flea (Daphnia magna Straus; Cladocera: Daphniidae) and the fathead minnow (Pimephales promelas Rafinesque; Cypriniformes: Cyprinidae). Water fleas and fish were placed directly into the solutions in glass containers and tanks for 48-hours and 96-hours, respectively. When applied within the above-mentioned range of effective mosquito larvicide concentrations, DL-methionine meets US EPA criteria as a "practically non-toxic" pesticide for both species. These results suggest that methionine is a viable alternative to current mosquito larvicide options, which are typically classified as moderately to highly toxic and may be a valuable addition to a mosquito integrated pest management program.
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Affiliation(s)
- Emma N I Weeks
- Entomology and Nematology Department, University of Florida, Gainesville, FL 32611, USA.
| | - Kevin J Kroll
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Timothy S Johnson
- The Department of Environmental Horticulture, UF/IFAS Plant Innovation Center, University of Florida, Gainesville, FL 32611, USA
| | - Thomas Colquhoun
- The Department of Environmental Horticulture, UF/IFAS Plant Innovation Center, University of Florida, Gainesville, FL 32611, USA
| | - James P Cuda
- Entomology and Nematology Department, University of Florida, Gainesville, FL 32611, USA
| | - Nancy D Denslow
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Bruce R Stevens
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL 32610, USA
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16
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Burtis JC, Poggi JD, McMillan JR, Crans SC, Campbell SR, Isenberg A, Pulver J, Casey P, White K, Zondag C, Badger JR, Berger R, Betz J, Giordano S, Kawalkowski M, Petersen JL, Williams G, Andreadis TG, Armstrong PM, Harrington LC. NEVBD Pesticide Resistance Monitoring Network: Establishing a Centralized Network to Increase Regional Capacity for Pesticide Resistance Detection and Monitoring. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:787-797. [PMID: 33128057 DOI: 10.1093/jme/tjaa236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Pesticide resistance in arthropod vectors of disease agents is a growing issue globally. Despite the importance of resistance monitoring to inform mosquito control programs, no regional monitoring programs exist in the United States. The Northeastern Regional Center for Excellence in Vector-Borne Diseases (NEVBD) is a consortium of researchers and public health practitioners with a primary goal of supporting regional vector control activities. NEVBD initiated a pesticide resistance monitoring program to detect resistant mosquito populations throughout the northeastern United States. A regionwide survey was distributed to vector control agencies to determine needs and refine program development and in response, a specimen submission system was established, allowing agencies to submit Culex pipiens (L.) (Diptera:Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) for pesticide resistance testing. NEVBD also established larvicide resistance diagnostics for Bacillus thuringiensis israelensis (Bti) and methoprene. Additional diagnostics were developed for Cx. pipiens resistance to Lysinibacillus sphaericus. We received 58 survey responses, representing at least one agency from each of the 13 northeastern U.S. states. Results indicated that larvicides were deployed more frequently than adulticides, but rarely paired with resistance monitoring. Over 18,000 mosquitoes were tested from six states. Widespread low-level (1 × LC-99) methoprene resistance was detected in Cx. pipiens, but not in Ae. albopictus. No resistance to Bti or L. sphaericus was detected. Resistance to pyrethroids was detected in many locations for both species. Our results highlight the need for increased pesticide resistance testing in the United States and we provide guidance for building a centralized pesticide resistance testing program.
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Affiliation(s)
- James C Burtis
- Department of Entomology, Cornell University, Ithaca, NY
| | - Joseph D Poggi
- Department of Entomology, Cornell University, Ithaca, NY
| | | | - Scott C Crans
- NJDEP Office of Mosquito Control Coordination, Trenton, NJ
| | | | - Amy Isenberg
- Rockland County Department of Health, Pomona, NY
| | | | - Patti Casey
- Vermont Agency of Agriculture, Food & Markets, Montpelier, VT
| | | | - Craig Zondag
- Lemon Fair Insect Control District, Weybridge, VT
| | - John R Badger
- Delaware Division of Fish and Wildlife, Mosquito Control Section, Milford, DE
| | - Russell Berger
- Morris County Division of Mosquito Control, Morristown, NJ
| | - John Betz
- Department of Public Works, Cumberland County Mosquito Control, Bridgeton, NJ 08302
| | | | | | - John L Petersen
- Center for Vector Biology, Rutgers University, New Brunswick, NJ
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Combining DL-Methionine and Bacillus thuringiensis Subspecies israelensis: Prospects for a Mosquito Larvicide. INSECTS 2020; 11:insects11120880. [PMID: 33322550 PMCID: PMC7764334 DOI: 10.3390/insects11120880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/25/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022]
Abstract
Simple Summary With the increasing threat that mosquito borne diseases pose to public health, the demand for environmentally sustainable pesticides has been increasing in recent years. Pesticides that target the larval stage (i.e., larvicides) are particularly useful for controlling mosquito populations as they strike at the source. Currently, Bacillus thuringiensis subspecies israelensis (BTI) is a commonly used mosquito larvicide but some studies show signs of resistance development. DL-methionine is an essential amino acid that has mosquito larvicidal capabilities, while also having minimal negative effects on non-target organisms in laboratory experiments. In this study, our objective was to evaluate the effect of these two larvicides individually and together at reducing mosquito survival. We found that while DL-methionine was more toxic to Anopheles quadrimaculatus than Aedes aegypti, the opposite was true for BTI. Additionally, when the combination was tested against An. quadrimaculatus larvae at higher concentrations the active ingredients were complementary and the effect was equal to both ingredients alone. However, the active ingredients were antagonistic when tested against Ae. aegypti larvae. These findings are important as they show the potential for DL-methionine and the combination of DL-methionine with BTI to be used as a larvicide against Anopheles mosquitoes, which are responsible for transmitting malaria. Abstract Mosquito larvicides can reduce mosquito populations at the source, potentially decreasing biting rates and pathogen transmission. However, there is a growing need for mosquito larvicides that are environmentally sustainable. Bacillus thuringiensis subspecies israelensis (BTI) is a naturally occurring bacterium commonly used as a larvicide to manage mosquito populations. Methionine is an essential amino acid that has demonstrated toxic properties against larval mosquitoes in laboratory experiments, while having minimal effects on non-target organisms. The goal of this study was to evaluate the potential for a novel combination larvicide by testing for compatibility between these two active ingredients. We began by determining the lethal concentration values (LCs) of BTI and DL-methionine against Anopheles quadrimaculatus Say and Aedes aegypti Linnaeus (Diptera: Culicidae) larvae. These bioassays were conducted in glass jars and mortality was observed 48 h post-treatment. We found that while DL-methionine was more toxic to An. quadrimaculatus than Ae. aegypti, the opposite was true for BTI. Then, we used these LCs to conduct bioassays with a combination of BTI and DL-methionine to determine the relationship between the two active ingredients when used against An. quadrimaculatus and Ae. aegypti larvae. The findings of this study demonstrate that BTI and DL-methionine have the potential to be complementary due to their additive properties at higher concentrations and effect levels when tested against An. quadrimaculatus. However, an antagonistic relationship was detected at the concentrations tested with Ae. aegypti. These results are encouraging and imply that a DL-methionine or BTI/DL-methionine combination larvicide could be used in management of Anopheles species.
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18
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Gimnig JE, Ombok M, Bayoh N, Mathias D, Ochomo E, Jany W, Walker ED. Efficacy of extended release formulations of Natular™ (spinosad) against larvae and adults of Anopheles mosquitoes in western Kenya. Malar J 2020; 19:436. [PMID: 33243237 PMCID: PMC7691113 DOI: 10.1186/s12936-020-03507-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Larval source management is recommended as a supplementary vector control measure for the prevention of malaria. Among the concerns related to larviciding is the feasibility of implementation in tropical areas with large numbers of habitats and the need for frequent application. Formulated products of spinosad that are designed to be effective for several weeks may mitigate some of these concerns. METHODS In a semi-field study, three formulations of spinosad (emulsifiable concentrate, extended release granules and tablet formulations) were tested in naturalistic habitats in comparison to an untreated control. Cohorts of third instar Anopheles gambiae (Diptera: Culicidae) were introduced into the habitats in screened cages every week up to four weeks after application and monitored for survivorship over three days. A small-scale field trial was then conducted in two villages. Two of the spinosad formulations were applied in one village over the course of 18 months. Immature mosquito populations were monitored with standard dippers in sentinel sites and adult populations were monitored by pyrethrum spray catches. RESULTS In the semi-field study, the efficacy of the emulsifiable concentrate of spinosad waned 1 week after treatment. Mortality in habitats treated with the extended release granular formulation of spinosad was initially high but declined gradually over 4 weeks while mortality in habitats treated with the dispersable tablet formulation was low immediately after treatment but rose to 100% through four weeks. In the field study, immature and adult Anopheles mosquito populations were significantly lower in the intervention village compared to the control village during the larviciding period. Numbers of collected mosquitoes were lower in the intervention village compared to the control village during the post-intervention period but the difference was not statistically significant. CONCLUSIONS The extended release granular formulation and the dispersible tablet formulations of spinosad are effective against larval Anopheles mosquitoes for up to four weeks and may be an effective tool as part of larval source management programmes for reducing adult mosquito density and malaria transmission.
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Affiliation(s)
- John E Gimnig
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, GA, USA.
| | - Maurice Ombok
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Nabie Bayoh
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
- PMI VectorLink Project, Abt Associates, Lusaka, Zambia
| | - Derrick Mathias
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, GA, USA
- Florida Medical Entomological Laboratory, University of Florida, Vero Beach, FL, USA
| | - Eric Ochomo
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | | | - Edward D Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
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19
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Brühl CA, Després L, Frör O, Patil CD, Poulin B, Tetreau G, Allgeier S. Environmental and socioeconomic effects of mosquito control in Europe using the biocide Bacillus thuringiensis subsp. israelensis (Bti). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 724:137800. [PMID: 32249002 DOI: 10.1016/j.scitotenv.2020.137800] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/06/2020] [Accepted: 03/06/2020] [Indexed: 06/11/2023]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) has been used in mosquito control programs to reduce nuisance in Europe for decades and is generally considered an environmentally-safe, effective and target-specific biocide. However, the use of Bti is not uncontroversial. Target mosquitoes and affected midges represent an important food source for many aquatic and terrestrial predators and reduction of their populations is likely to result in food-web effects at higher trophic levels. In the context of global biodiversity loss, this appears particularly critical since treated wetlands are often representing conservation areas. In this review, we address the current large-scale use of Bti for mosquito nuisance control in Europe, provide a description of its regulation followed by an overview of the available evidence on the parameters that are essential to evaluate Bti use in mosquito control. Bti accumulation and toxin persistence could result in a chronic expose of mosquito populations ultimately affecting their susceptibility, although observed increase in resistance to Bti in mosquito populations is low due to the four toxins involved. A careful independent monitoring of mosquito susceptibility, using sensitive bioassays, is mandatory to detect resistance development timely. Direct Bti effects were documented for non-target chironomids and other invertebrate groups and are discussed for amphibians. Field studies revealed contrasting results on possible impacts on chironomid abundances. Indirect, food-web effects were rarely studied in the environment. Depending on study design and duration, Bti effects on higher trophic levels were demonstrated or not. Further long-term field studies are needed, especially with observations of bird declines in Bti-treated wetland areas. Socio-economic relevance of mosquito control requires considering nuisance, vector-borne diseases and environmental effects jointly. Existing studies indicate that a majority of the population is concerned regarding potential environmental effects of Bti mosquito control and that they are willing to pay for alternative, more environment-friendly techniques.
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Affiliation(s)
- Carsten A Brühl
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, D-76829 Landau, Germany.
| | - Laurence Després
- Université Grenoble Alpes, CNRS, Laboratoire d'Ecologie Alpine, F-38000 Grenoble, France
| | - Oliver Frör
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, D-76829 Landau, Germany
| | - Chandrashekhar D Patil
- Centre of Island Research and Environmental Observatory, PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, F-66860 Perpignan, France
| | - Brigitte Poulin
- Tour du Valat, Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, F-13200 Arles, France
| | | | - Stefanie Allgeier
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, D-76829 Landau, Germany
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20
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Biological Control of Aedes albopictus: Obtained from the New Bacterial Candidates with Insecticidal Activity. INSECTS 2020; 11:insects11070403. [PMID: 32610661 PMCID: PMC7412510 DOI: 10.3390/insects11070403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 11/17/2022]
Abstract
Vector-borne deadly pathogens cause more than 700,000 deaths annually. They are transmitted by several vectors, among which the mosquito is the most important. Chemical compounds often have devastating side effects, leading to the abandonment of the majority of them. Biological control has been performed by using formulations of Bacillus sphaericus and Bacillus thuringiensis, but their intensive use has led to the emergence of resistance. Currently, the development of new alternative molecules is urgently needed, in order to use them in mosaics or in rotation with already known insecticides for the control of vectors, especially mosquitoes. Here, we attempted to identify bacterial species with potential anti-mosquito actions. Among bacterial strains isolated from dry sandy soil from Senegal, eleven strains from the Bacillales and Actinomycetales orders were chosen for the entomopathogenic activity experiments. Then, we tested their secondary metabolites, which were obtained from the supernatant fraction, and their cell wall and cytoplasmic compounds, which were found in the pellet fraction, in Aedes albopictus larvae, and compared the larval mortality rate with that obtained by using a commercial product. A total of 4/11 (36.36%) of the isolated species exhibited insecticidal activity. B. nealsonii, which is not a well-known bacterium, had the highest larvicidal effect with 70% of the larval mortality, which is highlighted for the first time. The Streptomyces species we isolated seem to be potential new species, and 3/5 (60%) of them exhibited insecticidal activity. Our study reports provide potential candidates for the identification of active molecules to be developed for strengthening the biological control of infectious diseases agents transmitted by mosquitoes.
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21
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Valtierra-de-Luis D, Villanueva M, Lai L, Williams T, Caballero P. Potential of Cry10Aa and Cyt2Ba, Two Minority δ-endotoxins Produced by Bacillus thuringiensis ser. israelensis, for the Control of Aedes aegypti Larvae. Toxins (Basel) 2020; 12:toxins12060355. [PMID: 32485828 PMCID: PMC7354544 DOI: 10.3390/toxins12060355] [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: 04/17/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 11/16/2022] Open
Abstract
Bacillus thuringiensis ser. israelensis (Bti) has been widely used as microbial larvicide for the control of many species of mosquitoes and blackflies. The larvicidal activity of Bti resides in Cry and Cyt δ-endotoxins present in the parasporal crystal of this pathogen. The insecticidal activity of the crystal is higher than the activities of the individual toxins, which is likely due to synergistic interactions among the crystal component proteins, particularly those involving Cyt1Aa. In the present study, Cry10Aa and Cyt2Ba were cloned from the commercial larvicide VectoBac-12AS® and expressed in the acrystalliferous Bt strain BMB171 under the cyt1Aa strong promoter of the pSTAB vector. The LC50 values for Aedes aegypti second instar larvae estimated at 24 hpi for these two recombinant proteins (Cry10Aa and Cyt2Ba) were 299.62 and 279.37 ng/mL, respectively. Remarkable synergistic mosquitocidal activity was observed between Cry10Aa and Cyt2Ba (synergistic potentiation of 68.6-fold) when spore + crystal preparations, comprising a mixture of both recombinant strains in equal relative concentrations, were ingested by A. aegypti larvae. This synergistic activity is among the most powerful described so far with Bt toxins and is comparable to that reported for Cyt1A when interacting with Cry4Aa, Cry4Ba or Cry11Aa. Synergistic mosquitocidal activity was also observed between the recombinant proteins Cyt2Ba and Cry4Aa, but in this case, the synergistic potentiation was 4.6-fold. In conclusion, although Cry10Aa and Cyt2Ba are rarely detectable or appear as minor components in the crystals of Bti strains, they represent toxicity factors with a high potential for the control of mosquito populations.
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Affiliation(s)
- Daniel Valtierra-de-Luis
- Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, 31006 Pamplona, Spain; (D.V.-d.-L.); (M.V.); (L.L.)
| | - Maite Villanueva
- Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, 31006 Pamplona, Spain; (D.V.-d.-L.); (M.V.); (L.L.)
- Bioinsectis SL, Avda Pamplona 123, 31192 Mutilva, Spain
| | - Liliana Lai
- Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, 31006 Pamplona, Spain; (D.V.-d.-L.); (M.V.); (L.L.)
| | | | - Primitivo Caballero
- Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra, 31006 Pamplona, Spain; (D.V.-d.-L.); (M.V.); (L.L.)
- Bioinsectis SL, Avda Pamplona 123, 31192 Mutilva, Spain
- Institute for Multidisciplinary Applied Biology Research (IMAB), Universidad Pública de Navarra, 31006 Mutilva, Spain
- Correspondence:
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22
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Dahmana H, Mediannikov O. Mosquito-Borne Diseases Emergence/Resurgence and How to Effectively Control It Biologically. Pathogens 2020; 9:E310. [PMID: 32340230 PMCID: PMC7238209 DOI: 10.3390/pathogens9040310] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/28/2022] Open
Abstract
Deadly pathogens and parasites are transmitted by vectors and the mosquito is considered the most threatening vector in public health, transmitting these pathogens to humans and animals. We are currently witnessing the emergence/resurgence in new regions/populations of the most important mosquito-borne diseases, such as arboviruses and malaria. This resurgence may be the consequence of numerous complex parameters, but the major cause remains the mismanagement of insecticide use and the emergence of resistance. Biological control programmes have rendered promising results but several highly effective techniques, such as genetic manipulation, remain insufficiently considered as a control mechanism. Currently, new strategies based on attractive toxic sugar baits and new agents, such as Wolbachia and Asaia, are being intensively studied for potential use as alternatives to chemicals. Research into new insecticides, Insect Growth Regulators, and repellent compounds is pressing, and the improvement of biological strategies may provide key solutions to prevent outbreaks, decrease the danger to at-risk populations, and mitigate resistance.
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Affiliation(s)
- Handi Dahmana
- Aix Marseille Univ, IRD, AP-HM, MEPHI, 13005 Marseille, France;
- IHU-Méditerranée Infection, 13005 Marseille, France
| | - Oleg Mediannikov
- Aix Marseille Univ, IRD, AP-HM, MEPHI, 13005 Marseille, France;
- IHU-Méditerranée Infection, 13005 Marseille, France
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23
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Functional Bacillus thuringiensis Cyt1Aa Is Necessary To Synergize Lysinibacillus sphaericus Binary Toxin (Bin) against Bin-Resistant and -Refractory Mosquito Species. Appl Environ Microbiol 2020; 86:AEM.02770-19. [PMID: 32005737 DOI: 10.1128/aem.02770-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
The binary (Bin) toxin from Lysinibacillus sphaericus is effective to mosquito larvae, but its utilization is threatened by the development of insect resistance. Bin toxin is composed of the BinB subunit required for binding to midgut receptors and the BinA subunit that causes toxicity after cell internalization, mediated by BinB. Culex quinquefasciatus resistance to this toxin is caused by mutations that prevent expression of Bin toxin receptors in the midgut. Previously, it was shown that the Cyt1Aa toxin from Bacillus thuringiensis subsp. israelensis restores Bin toxicity to Bin-resistant C. quinquefasciatus and to Aedes aegypti larvae, which are naturally devoid of functional Bin receptors. Our goal was to elucidate the mechanism involved in Cyt1Aa synergism with Bin in such larvae. In vivo assays showed that the mixture of Bin toxin, or its BinA subunit, with Cyt1Aa was effective to kill resistant larvae. However, no specific binding interaction between Cyt1Aa and the Bin toxin, or its subunits, was observed. The synergy between Cyt1Aa and Bin toxins is dependent on functional Cyt1Aa, as demonstrated by using the nontoxic Cyt1AaV122E mutant toxin affected in oligomerization and membrane insertion, which was unable to synergize Bin toxicity in resistant larvae. The synergism correlated with the internalization of Bin or BinA into anterior and medium midgut epithelial cells, which occurred only in larvae treated with wild-type Cyt1Aa toxin. This toxin is able to overcome failures in the binding step involving BinB receptor by allowing the internalization of Bin toxin, or its BinA subunit, into the midgut cells.IMPORTANCE One promising management strategy for mosquito control is the utilization of a mixture of L. sphaericus and B. thuringiensis subsp. israelensis insecticidal toxins. From this set, Bin and Cyt1Aa toxins synergize and display toxicity to resistant C. quinquefasciatus and to A. aegypti larvae, whose midgut cells lack Bin toxin receptors. Our data set provides evidence that functional Cyt1Aa is essential for internalization of Bin or its BinA subunit into such cells, but binding interaction between Bin and Cyt1Aa is not observed. Thus, this mechanism contrasts with that for the synergy between Cyt1Aa and the B. thuringiensis subsp. israelensis Cry toxins, where active Cyt1Aa is not necessary but a specific binding between Cry and Cyt1Aa is required. Our study established the initial molecular basis of the synergy between Bin and Cyt1Aa, and these findings enlarge our knowledge of their mode of action, which could help to develop improved strategies to cope with insect resistance.
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Francis S, Crawford J, McKenzie S, Campbell T, Wright D, Hamilton T, Huntley-Jones S, Spence S, Belemvire A, Alavi K, Gutierrez CT. Comparative toxicity of larvicides and growth inhibitors on Aedes aegypti from select areas in Jamaica. ROYAL SOCIETY OPEN SCIENCE 2020; 7:192041. [PMID: 32269812 PMCID: PMC7137934 DOI: 10.1098/rsos.192041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/24/2020] [Indexed: 06/11/2023]
Abstract
Insecticide resistance has become problematic in tropical and subtropical regions, where Aedes mosquitoes and Aedes-borne arboviral diseases thrive. With the recent occurrence of chikungunya and the Zika virus in Jamaica, the Ministry of Health and Wellness, Jamaica, partnered with the United States Agency for International Development to implement multiple intervention activities to reduce the Aedes aegypti populations in seven parishes across the island and to assess the susceptibility of collected samples to various concentrations of temephos, Bacillus thuringiensis subsp. israelensis, (Bti), diflubenzuron and methoprene. Of the insecticides tested, only temephos has been used in routine larviciding activities in the island. The results showed that only temephos at concentrations 0.625 ppm and Bti at concentrations 6-8 ppm were effective at causing 98-100% mortality of local Ae. aegypti at 24 h exposure. Surprisingly, the growth inhibitors diflubenzuron and methoprene had minimal effect at preventing adult emergence in Ae. aegypti larvae in the populations tested. The results demonstrate the need for insecticide resistance testing as a routine part of vector control monitoring activies in order to determine useful tools that may be incorporated to reduce the abundance of Ae. aegypti.
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Affiliation(s)
- Sheena Francis
- Natural Products Institute, University of the West Indies, Mona, Jamaica
- Abt Associates, 70 Half-Way Tree Road, Kingston, Jamaica
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | - Jervis Crawford
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | - Sashell McKenzie
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | - Towanna Campbell
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | - Danisha Wright
- Natural Products Institute, University of the West Indies, Mona, Jamaica
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | - Trevann Hamilton
- Zika AIRS Project Jamaica, 70 Half-Way Tree Road, Kingston, Jamaica
| | | | - Simone Spence
- Health Promotions and Protection, Ministry of Health and Wellness, Kingston, Jamaica
| | - Allison Belemvire
- United States Agency for International Development (USAID), Bureau for Global Health, Office of Infectious Disease, Malaria Division, Arlington, TX, USA
| | - Kristen Alavi
- United States Agency for International Development (USAID), Washington, DC, USA
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25
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Noskov YA, Polenogova OV, Yaroslavtseva ON, Belevich OE, Yurchenko YA, Chertkova EA, Kryukova NA, Kryukov VY, Glupov VV. Combined effect of the entomopathogenic fungus Metarhizium robertsii and avermectins on the survival and immune response of Aedes aegypti larvae. PeerJ 2019; 7:e7931. [PMID: 31667017 PMCID: PMC6816395 DOI: 10.7717/peerj.7931] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 09/23/2019] [Indexed: 12/18/2022] Open
Abstract
Combination of insect pathogenic fungi and microbial metabolites is a prospective method for mosquito control. The effect of the entomopathogenic fungus Metarhizium robertsii J.F. Bischoff, S.A. Rehner & Humber and avermectins on the survival and physiological parameters of Aedes aegypti (Linnaeus, 1762) larvae (dopamine concentration, glutathione S-transferase (GST), nonspecific esterases (EST), acid proteases, lysozyme-like, phenoloxidase (PO) activities) was studied. It is shown that the combination of these agents leads to a synergistic effect on mosquito mortality. Colonization of Ae. aegypti larvae by hyphal bodies following water inoculation with conidia is shown for the first time. The larvae affected by fungi are characterized by a decrease in PO and dopamine levels. In the initial stages of toxicosis and/or fungal infection (12 h posttreatment), increases in the activity of insect detoxifying enzymes (GST and EST) and acid proteases are observed after monotreatments, and these increases are suppressed after combined treatment with the fungus and avermectins. Lysozyme-like activity is also most strongly suppressed under combined treatment with the fungus and avermectins in the early stages posttreatment (12 h). Forty-eight hours posttreatment, we observe increases in GST, EST, acid proteases, and lysozyme-like activities under the influence of the fungus and/or avermectins. The larvae affected by avermectins accumulate lower levels of conidia than avermectin-free larvae. On the other hand, a burst of bacterial CFUs is observed under treatment with both the fungus and avermectins. We suggest that disturbance of the responses of the immune and detoxifying systems under the combined treatment and the development of opportunistic bacteria may be among the causes of the synergistic effect.
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Affiliation(s)
- Yuriy A Noskov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia.,Tomsk State University, Tomsk, Russia
| | - Olga V Polenogova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Olga N Yaroslavtseva
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Olga E Belevich
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Yuriy A Yurchenko
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Ekaterina A Chertkova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Natalya A Kryukova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Vadim Yu Kryukov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Viktor V Glupov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
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26
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Derua YA, Kahindi SC, Mosha FW, Kweka EJ, Atieli HE, Zhou G, Lee MC, Githeko AK, Yan G. Susceptibility of Anopheles gambiae complex mosquitoes to microbial larvicides in diverse ecological settings in western Kenya. MEDICAL AND VETERINARY ENTOMOLOGY 2019; 33:220-227. [PMID: 30628101 PMCID: PMC6995353 DOI: 10.1111/mve.12353] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/20/2018] [Accepted: 11/01/2018] [Indexed: 05/26/2023]
Abstract
The microbial larvicides Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) (Bacillales: Bacillaceae) are well known for their efficacy and safety in mosquito control. In order to assess their potential value in future mosquito control strategies in western Kenya, the current study tested the susceptibility of five populations of Anopheles gambiae complex mosquitoes (Diptera: Culicidae), collected from five diverse ecological sites in this area, to Bti and Bs under laboratory conditions. In each population, bioassays were conducted with eight concentrations of larvicide (Bti/Bs) in four replicates and were repeated on three separate days. Larval mortality was recorded at 24 h or 48 h after the application of larvicide and subjected to probit analysis. A total of 2400 An. gambiae complex larvae from each population were tested for their susceptibility to Bti and Bs. The mean (± standard error of the mean, SEM) lethal concentration values of Bti required to achieve 50% and 95% larval mortality (LC50 and LC95 ) across the five populations were 0.062 (± 0.005) mg/L and 0.797 (± 0.087) mg/L, respectively. Corresponding mean (± SEM) values for Bs were 0.058 (± 0.005) mg/L and 0.451 (± 0.053) mg/L, respectively. Statistical analysis indicated that the five populations of An. gambiae complex mosquitoes tested were fully susceptible to Bti and Bs, and there was no significant variation in susceptibility among the tested populations.
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Affiliation(s)
- Y A Derua
- Department of Parasitology and Entomology, Kilimanjaro Christian Medical University College, Tumaini University Makumira, Moshi, Tanzania
- Department of Research Programmes, National Institute for Medical Research, Amani Research Centre, Tanga, Tanzania
| | - S C Kahindi
- Department of Zoology, School of Pure and Applied Sciences, Pwani University, Kilifi, Kenya
| | - F W Mosha
- Department of Parasitology and Entomology, Kilimanjaro Christian Medical University College, Tumaini University Makumira, Moshi, Tanzania
| | - E J Kweka
- Division of Livestock and Human Diseases Vector Control, Tropical Pesticides Research Institute, Arusha, Tanzania
- Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - H E Atieli
- Department of Public Health, Maseno University, Kisumu, Kenya
| | - G Zhou
- Programme in Public Health, College of Health Sciences, University of California Irvine, Irvine, CA, U.S.A
| | - M-C Lee
- Programme in Public Health, College of Health Sciences, University of California Irvine, Irvine, CA, U.S.A
| | - A K Githeko
- Climate and Human Health Research Unit, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - G Yan
- Programme in Public Health, College of Health Sciences, University of California Irvine, Irvine, CA, U.S.A
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Abstract
Zika virus infection and dengue and chikungunya fevers are emerging viral diseases that have become public health threats. Their aetiologic agents are transmitted by the bite of genus Aedes mosquitoes. Without effective therapies or vaccines, vector control is the main strategy for preventing the spread of these diseases. Increased insecticide resistance calls for biorational actions focused on control of the target vector population. The chitin required for larval survival structures is a good target for biorational control. Chitin synthases A and B (CHS) are enzymes in the chitin synthesis pathway. Double-stranded RNA (dsRNA)-mediated gene silencing (RNAi) achieves specific knockdown of target proteins. Our goal in this work, a new proposed RNAi-based bioinsecticide, was developed as a potential strategy for mosquito population control. DsRNA molecules that target five different regions in the CHSA and B transcript sequences were produced in vitro and in vivo through expression in E. coli HT115 and tested by direct addition to larval breeding water. Mature and immature larvae treated with dsRNA targeting CHS catalytic sites showed significantly decreased viability associated with a reduction in CHS transcript levels. The few larval and adult survivors displayed an altered morphology and chitin content. In association with diflubenzuron, this bioinsecticide exhibited insecticidal adjuvant properties.
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28
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Sato R, Adegawa S, Li X, Tanaka S, Endo H. Function and Role of ATP-Binding Cassette Transporters as Receptors for 3D-Cry Toxins. Toxins (Basel) 2019; 11:E124. [PMID: 30791434 PMCID: PMC6409751 DOI: 10.3390/toxins11020124] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/13/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022] Open
Abstract
When ABC transporter family C2 (ABCC2) and ABC transporter family B1 (ABCB1) were heterologously expressed in non-susceptible cultured cells, the cells swelled in response to Cry1A and Cry3 toxins, respectively. Consistent with the notion that 3D-Cry toxins form cation-permeable pores, Bombyx mori ABCC2 (BmABCC2) facilitated cation-permeable pore formation by Cry1A when expressed in Xenopus oocytes. Furthermore, BmABCC2 had a high binding affinity (KD) to Cry1Aa of 3.1 × 10-10 M. These findings suggest that ABC transporters, including ABCC2 and ABCB1, are functional receptors for 3D-Cry toxins. In addition, the Cry2 toxins most distant from Cry1A toxins on the phylogenetic tree used ABC transporter A2 as a receptor. These data suggest that 3D-Cry toxins use ABC transporters as receptors. In terms of inducing cell swelling, ABCC2 has greater activity than cadherin-like receptor. The pore opening of ABC transporters was hypothesized to be linked to their receptor function, but this was repudiated by experiments using mutants deficient in export activity. The synergistic relationship between ABCC2 and cadherin-like receptor explains their ability to cause resistance in one species of insect.
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Affiliation(s)
- Ryoichi Sato
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Satomi Adegawa
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Xiaoyi Li
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Shiho Tanaka
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Haruka Endo
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
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29
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Carvalho KDS, Crespo MM, Araújo AP, da Silva RS, de Melo-Santos MAV, de Oliveira CMF, Silva-Filha MHNL. Long-term exposure of Aedes aegypti to Bacillus thuringiensis svar. israelensis did not involve altered susceptibility to this microbial larvicide or to other control agents. Parasit Vectors 2018; 11:673. [PMID: 30594214 PMCID: PMC6311009 DOI: 10.1186/s13071-018-3246-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/29/2018] [Indexed: 01/13/2023] Open
Abstract
Background Bacillus thuringiensis svar. israelensis (Bti) is an effective and safe biolarvicide to control Aedes aegypti. Its mode of action based on four protoxins disfavors resistance; however, control in endemic areas that display high mosquito infestation throughout the year requires continuous larvicide applications, which imposes a strong selection pressure. Therefore, this study aimed to investigate the effects of an intensive Bti exposure on an Ae. aegypti strain (RecBti), regarding its susceptibility to Bti and two of its protoxins tested individually, to other control agents temephos and diflubenzuron, and its profile of detoxifying enzymes. Methods The RecBti strain was established using a large egg sample (10,000) from Recife city (Brazil) and more than 290,000 larvae were subjected to Bti throughout 30 generations. Larvae susceptibility to larvicides and the activity of detoxifying enzymes were determined by bioassays and catalytic assays, respectively. The Rockefeller strain was the reference used for these evaluations. Results Bti exposure yielded an average of 74% mortality at each generation. Larvae assessed in seven time points throughout the 30 generations were susceptible to Bti crystal (resistance ratio RR ≤ 2.8) and to its individual toxins Cry11Aa and Cry4Ba (RR ≤ 4.1). Early signs of altered susceptibility to Cry11Aa were detected in the last evaluations, suggesting that this toxin was a marker of the selection pressure imposed. RecBti larvae were also susceptible (RR ≤ 1.6) to the other control agents, temephos and diflubenzuron. The activity of the detoxifying enzymes α- and β-esterases, glutathione-S-transferases and mixed-function oxidases was classified as unaltered in larvae from two generations (F19 and F25), except for a β-esterases increase in F25. Conclusions Prolonged exposure of Ae. aegypti larvae to Bti did not evolve into resistance to the crystal, and no cross-resistance with temephos and diflubenzuron were recorded, which supports their sustainable use with Bti for integrated control practices. The unaltered activity of most detoxifying enzymes suggests that they might not play a major role in the metabolism of Bti toxins, therefore resistance by this mechanism is unlikely to occur. This study also highlights the need to establish suitable criteria to classify the status of larval susceptibility/resistance. Electronic supplementary material The online version of this article (10.1186/s13071-018-3246-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Mônica Maria Crespo
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife, PE, 50740-465, Brazil
| | - Ana Paula Araújo
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife, PE, 50740-465, Brazil
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Larval Exposure to the Bacterial Insecticide Bti Enhances Dengue Virus Susceptibility of Adult Aedes aegypti Mosquitoes. INSECTS 2018; 9:insects9040193. [PMID: 30558130 PMCID: PMC6316598 DOI: 10.3390/insects9040193] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/07/2018] [Accepted: 12/12/2018] [Indexed: 02/06/2023]
Abstract
Understanding the interactions between pathogens sharing the same host can be complicated for holometabolous animals when larval and adult stages are exposed to distinct pathogens. In medically important insect vectors, the effect of pathogen exposure at the larval stage may influence susceptibility to human pathogens at the adult stage. We addressed this hypothesis in the mosquito Aedes aegypti, a major vector of arthropod-borne viruses (arboviruses), such as the dengue virus (DENV) and the chikungunya virus (CHIKV). We experimentally assessed the consequences of sub-lethal exposure to the bacterial pathogen Bacillus thuringiensis subsp. israelensis (Bti), during larval development, on arbovirus susceptibility at the adult stage in three Ae. aegypti strains that differ in their genetic resistance to Bti. We found that larval exposure to Bti significantly increased DENV susceptibility, but not CHIKV susceptibility, in the Bti-resistant strains. However, there was no major difference in the baseline arbovirus susceptibility between the Bti-resistant strains and their Bti-susceptible parental strain. Although the generality of our results remains to be tested with additional arbovirus strains, this study supports the idea that the outcome of an infection by a pathogen depends on other pathogens sharing the same host even when they do not affect the same life stage of the host. Our findings may also have implications for Bti as a mosquito biocontrol agent, indicating that the sub-optimal Bti efficacy may have counter-productive effects by increasing vector competence, at least for some combinations of arbovirus and mosquito strains.
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Derua YA, Kahindi SC, Mosha FW, Kweka EJ, Atieli HE, Wang X, Zhou G, Lee M, Githeko AK, Yan G. Microbial larvicides for mosquito control: Impact of long lasting formulations of Bacillus thuringiensis var. israelensis and Bacillus sphaericus on non-target organisms in western Kenya highlands. Ecol Evol 2018; 8:7563-7573. [PMID: 30151171 PMCID: PMC6106196 DOI: 10.1002/ece3.4250] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 04/11/2018] [Accepted: 05/18/2018] [Indexed: 11/14/2022] Open
Abstract
The microbial larvicides Bacillus thuringiensis var. israelensis and Bacillus sphaericus have been used extensively for mosquito control and have been found to be effective and safe to non-target organisms cohabiting with mosquito larvae. Recently developed long lasting microbial larvicides (LLML), although evading the previous challenge of short duration of activity, increase the risk of persistence of toxins in the treated larval habitats. This study monitored the impact of LLML FourStar® and LL3 on non-target organisms cohabiting with mosquito larvae in an operational study to control malaria vectors in western Kenya highlands. A total of 300 larval habitats were selected in three highland villages. The habitats were first monitored for 5 weeks to collect baseline data on non-target organisms cohabiting with mosquito larvae and then randomized into two treatment arms (respective FourStar® and LL3) and one control arm. Non-target organisms were sampled weekly for 5 months after treatment to assess the impact of LLML intervention. Before treatment, the mean density of all non-target organisms combined in the control, LL3 and FourStar® treated habitats was 1.42, 1.39 and 1.49 individuals per habitat per sampling occasion, respectively. Following treatment, this density remained fairly unchanged for 21 weeks at which time it was 1.82, 2.11, and 2.05 for the respective control, LL3 and FourStar® treated habitats. Statistical analysis revealed that LL3 and FourStar® did not significantly alter abundance, richness or diversity of the 11 taxa studied, when comparing the intervention and control larval habitats. However, both FourStar® and LL3 significantly reduced the density of malaria vectors. In conclusion, one round of label rate application of FourStar® or LL3 in natural larval habitats did not alter richness, abundance or diversity of the monitored aquatic non-target organisms cohabiting with mosquito larvae to an ecologically significant level.
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Affiliation(s)
- Yahya A. Derua
- Kilimanjaro Christian Medical University CollegeTumaini University MakumiraMoshiTanzania
- National Institute for Medical ResearchAmani Research CentreTangaTanzania
| | - Samuel C. Kahindi
- Department of ZoologySchool of Pure and Applied SciencesPwani UniversityKilifiKenya
| | - Franklin W. Mosha
- Kilimanjaro Christian Medical University CollegeTumaini University MakumiraMoshiTanzania
| | - Eliningaya J. Kweka
- Division of Livestock and Human Diseases Vector ControlTropical Pesticides Research InstituteArushaTanzania
- Department of Medical Parasitology and EntomologyCatholic University of Health and Allied SciencesMwanzaTanzania
| | | | - Xiaoming Wang
- Program in Public HealthCollege of Health SciencesUniversity of CaliforniaIrvineCalifornia
| | - Guofa Zhou
- Program in Public HealthCollege of Health SciencesUniversity of CaliforniaIrvineCalifornia
| | - Ming‐Chieh Lee
- Program in Public HealthCollege of Health SciencesUniversity of CaliforniaIrvineCalifornia
| | - Andrew K. Githeko
- Climate and Human Health Research UnitCentre for Global Health ResearchKenya Medical Research InstituteKisumuKenya
| | - Guiyun Yan
- Program in Public HealthCollege of Health SciencesUniversity of CaliforniaIrvineCalifornia
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Bacterial microbiota of Aedes aegypti mosquito larvae is altered by intoxication with Bacillus thuringiensis israelensis. Parasit Vectors 2018; 11:121. [PMID: 29499735 PMCID: PMC5834902 DOI: 10.1186/s13071-018-2741-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 02/23/2018] [Indexed: 12/11/2022] Open
Abstract
Background Insect microbiota is a dynamic microbial community that can actively participate in defense against pathogens. Bacillus thuringiensis (Bt) is a natural entomopathogen widely used as a bioinsecticide for pest control. Although Bt’s mode of action has been extensively studied, whether the presence of microbiota is mandatory for Bt to effectively kill the insect is still under debate. An association between a higher tolerance and a modified microbiota was already evidenced but a critical point remained to be solved: is the modified microbiota a cause or a consequence of a higher tolerance to Bt? Methods In this study we focused on the mosquito species Aedes aegypti, as no work has been performed on Diptera on this topic to date, and on B. thuringiensis israelensis (Bti), which is used worldwide for mosquito control. To avoid using antibiotics to cure bacterial microbiota, mosquito larvae were exposed to an hourly increasing dose of Bti during 25 hours to separate the most susceptible larvae dying quickly from more tolerant individuals, with longer survival. Results Denaturing gradient gel electrophoresis (DGGE) fingerprinting revealed that mosquito larval bacterial microbiota was strongly affected by Bti infection after only a few hours of exposure. Bacterial microbiota from the most tolerant larvae showed the lowest diversity but the highest inter-individual differences. The proportion of Bti in the host tissue was reduced in the most tolerant larvae as compared to the most susceptible ones, suggesting an active control of Bti infection by the host. Conclusions Here we show that a modified microbiota is associated with a higher tolerance of mosquitoes to Bti, but that it is rather a consequence of Bti infection than the cause of the higher tolerance. This study paves the way to future investigations aiming at unraveling the role of host immunity, inter-species bacterial competition and kinetics of host colonization by Bti that could be at the basis of the phenotype observed in this study. Electronic supplementary material The online version of this article (10.1186/s13071-018-2741-8) contains supplementary material, which is available to authorized users.
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Thammasittirong A, Prigyai K, Thammasittirong SNR. Mosquitocidal potential of silver nanoparticles synthesized using local isolates of Bacillus thuringiensis subsp. israelensis and their synergistic effect with a commercial strain of B. thuringiensis subsp. israelensis. Acta Trop 2017; 176:91-97. [PMID: 28754251 DOI: 10.1016/j.actatropica.2017.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/13/2017] [Accepted: 07/19/2017] [Indexed: 11/26/2022]
Abstract
Control of larval stages of Aedes aegypti is considered an effective approach for preventing outbreaks of dengue fever. In this work, silver nanoparticles (Ag NPs) were synthesized using the supernatant and insecticidal proteins from local isolates of Bacillus thuringiensis subsp. israelensis (Bti). Mosquitocidal activity assays against A. aegypti larvae revealed that the highest toxicity was obtained from the Ag NPs synthesized using supernatant of Bti K55 and the inclusion proteins of Bti K46 with a lethal concentration 50 (LC50) of 0.001 and 0.008μg/mL, respectively. The synthesized nanoparticles were characterized using UV-vis absorption spectrophotometry, scanning electron microscopy (SEM), SEM coupled with energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier-transform infrared spectroscopy. The synergistic studies revealed that the Ag NPs synthesized using supernatant of Bti K55 were synergized with commercial Bti cells with a synergistic factor (SF) of 3.3 and 10.0 for LC50 and LC90, respectively. In addition, the Ag NPs synthesized using inclusion proteins of Bti K46 were synergized with commercial Bti cells with a SF of 1.6 and 4.2 for LC50 and LC90, respectively. This study provided the first report of the synergistic effect between Bti and Ag NPs. Such a combination could represent an effective approach for the control of the dengue vector and possibly reducing the likelihood of increased insect resistance to chemical control.
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Mbatchou VC, Tchouassi DP, Dickson RA, Annan K, Mensah AY, Amponsah IK, Jacob JW, Cheseto X, Habtemariam S, Torto B. Mosquito larvicidal activity of Cassia tora seed extract and its key anthraquinones aurantio-obtusin and obtusin. Parasit Vectors 2017; 10:562. [PMID: 29126433 PMCID: PMC5681828 DOI: 10.1186/s13071-017-2512-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/31/2017] [Indexed: 12/22/2022] Open
Abstract
Background The edible and medicinal leguminous plant Cassia tora L. (Fabaceae) is known to possess insecticidal properties against a wide range of plant-feeding insects. However, the bioactivity of extracts of this plant and their constituents against vectors of medical importance has been largely unexplored. We investigated the mosquito larvicidal activity of the seed extract and its major anthraquinones against larvae of the African malaria vector Anopheles gambiae (s.s.). Methods Third-fourth instar larval mortality was observed after 24, 48, 72 and 96 h of exposure to varying doses of the extracts, and two anthraquinones isolates identified using liquid chromatography- quadrupole time of flight mass spectrometry (LC-QtoF-MS). The mosquito larval mortality was evaluated relative to the natural insecticide azadirachtin. Results Fractionation of the crude extract decreased mosquito larvicidal activity, however, larvicidal activity increased with increasing dose of the treatment and exposure time. The known anthraquinones aurantio-obtusin and obtusin were identified as key larvicidal compounds. Aurantio-obtusin and obtusin, exhibited similar toxicity to larvae of A. gambiae (s.s.) with LD50 values of 10 and 10.2 ppm, respectively. However, the two anthraquinones were four- and ~ six-fold less potent than that of the crude seed extract and azadirachtin, which had comparable LD50 values of 2.5 and 1.7 ppm, respectively. Conclusion Both aurantio-obtusin and obtusin showed mosquito larvicidal activity which were comparable to their respective fractions although they were less potent relative to the crude extract and azadirachtin. Further studies need to be conducted on C. tora for its exploitation as a potential eco-friendly tool in mosquito larval source reduction.
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Affiliation(s)
- Valentine C Mbatchou
- Department of Applied Chemistry and Biochemistry, University for Development Studies, Navrongo Campus, Navrongo, Ghana.,Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - David P Tchouassi
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi, Kenya
| | - Rita A Dickson
- Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Kofi Annan
- Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Abraham Y Mensah
- Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Isaac K Amponsah
- Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Julia W Jacob
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi, Kenya
| | - Xavier Cheseto
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi, Kenya
| | - Solomon Habtemariam
- Pharmacognosy Research Laboratories and Herbal Analysis Services UK, University of Greenwich, Chatham-Maritime, Kent, ME4 4TB, UK
| | - Baldwyn Torto
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi, Kenya. .,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.
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Suter T, Crespo MM, de Oliveira MF, de Oliveira TSA, de Melo-Santos MAV, de Oliveira CMF, Ayres CFJ, Barbosa RMR, Araújo AP, Regis LN, Flacio E, Engeler L, Müller P, Silva-Filha MHNL. Insecticide susceptibility of Aedes albopictus and Ae. aegypti from Brazil and the Swiss-Italian border region. Parasit Vectors 2017; 10:431. [PMID: 28927441 PMCID: PMC5606125 DOI: 10.1186/s13071-017-2364-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 09/07/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Aedes aegypti and Ae. albopictus are two highly invasive mosquito species, both vectors of several viruses, including dengue, chikungunya and Zika. While Ae. aegypti is the primary vector in the tropics and sub-tropics, Ae. albopictus is increasingly under the public health watch as it has been implicated in arbovirus-transmission in more temperate regions, including continental Europe. Vector control using insecticides is the pillar of most control programmes; hence development of insecticide resistance is of great concern. As part of a Brazilian-Swiss Joint Research Programme we set out to assess whether there are any signs of existing or incipient insecticide resistance primarily against the larvicide Bacillus thuringiensis svar. israelensis (Bti), but also against currently applied and potentially alternative insecticides in our areas, Recife (Brazil) and the Swiss-Italian border region. METHODS Following World Health Organization guidelines, dose-response curves for a range of insecticides were established for both colonized and field caught Ae. aegypti and Ae. albopictus. The larvicides included Bti, two of its toxins, Cry11Aa and Cry4Ba, Lysinibacillus sphaericus, Vectomax CG®, a formulated combination of Bti and L. sphaericus, and diflubenzuron. In addition to the larvicides, the Swiss-Italian Ae. albopictus populations were also tested against five adulticides (bendiocarb, dichlorodiphenyltrichloroethane, malathion, permethrin and λ-cyhalothrin). RESULTS Showing a similar dose-response, all mosquito populations were fully susceptible to the larvicides tested and, in particular, to Bti which is currently used both in Brazil and Switzerland. In addition, there were no signs of incipient resistance against Bti as larvae were equally susceptible to the individual toxins, Cry11Aa and Cry4Ba. The field-caught Swiss-Italian populations were susceptible to the adulticides tested but DDT mortality rates showed signs of reduced susceptibility. CONCLUSIONS The insecticides currently used for mosquito control in Switzerland and Brazil are still effective against the target populations. The present study provides an important reference as relatively few insecticide susceptibility surveys have been carried out with Ae. albopictus.
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Affiliation(s)
- Tobias Suter
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, PO Box, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
- Avia-GIS, Risschotlei 33, 2980 Zoersel, Belgium
| | - Mônica Maria Crespo
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife 50740-465, Brazil
| | | | | | | | | | | | | | - Ana Paula Araújo
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife 50740-465, Brazil
| | - Lêda Narcisa Regis
- Department of Entomology, Instituto Aggeu Magalhães-FIOCRUZ, Recife 50740-465, Brazil
| | - Eleonora Flacio
- Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland, Bellinzona, Switzerland
| | - Lukas Engeler
- Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland, Bellinzona, Switzerland
| | - Pie Müller
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, PO Box, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
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Moyes CL, Vontas J, Martins AJ, Ng LC, Koou SY, Dusfour I, Raghavendra K, Pinto J, Corbel V, David JP, Weetman D. Contemporary status of insecticide resistance in the major Aedes vectors of arboviruses infecting humans. PLoS Negl Trop Dis 2017; 11:e0005625. [PMID: 28727779 PMCID: PMC5518996 DOI: 10.1371/journal.pntd.0005625] [Citation(s) in RCA: 423] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Both Aedes aegytpi and Ae. albopictus are major vectors of 5 important arboviruses (namely chikungunya virus, dengue virus, Rift Valley fever virus, yellow fever virus, and Zika virus), making these mosquitoes an important factor in the worldwide burden of infectious disease. Vector control using insecticides coupled with larval source reduction is critical to control the transmission of these viruses to humans but is threatened by the emergence of insecticide resistance. Here, we review the available evidence for the geographical distribution of insecticide resistance in these 2 major vectors worldwide and map the data collated for the 4 main classes of neurotoxic insecticide (carbamates, organochlorines, organophosphates, and pyrethroids). Emerging resistance to all 4 of these insecticide classes has been detected in the Americas, Africa, and Asia. Target-site mutations and increased insecticide detoxification have both been linked to resistance in Ae. aegypti and Ae. albopictus but more work is required to further elucidate metabolic mechanisms and develop robust diagnostic assays. Geographical distributions are provided for the mechanisms that have been shown to be important to date. Estimating insecticide resistance in unsampled locations is hampered by a lack of standardisation in the diagnostic tools used and by a lack of data in a number of regions for both resistance phenotypes and genotypes. The need for increased sampling using standard methods is critical to tackle the issue of emerging insecticide resistance threatening human health. Specifically, diagnostic doses and well-characterised susceptible strains are needed for the full range of insecticides used to control Ae. aegypti and Ae. albopictus to standardise measurement of the resistant phenotype, and calibrated diagnostic assays are needed for the major mechanisms of resistance.
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Affiliation(s)
- Catherine L. Moyes
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - John Vontas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
- Department of Crop Science, Pesticide Science Lab, Agricultural University of Athens, Athens, Greece
| | - Ademir J. Martins
- Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Manguinhos, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Helios Block, Singapore
| | - Sin Ying Koou
- Environmental Health Institute, National Environment Agency, Helios Block, Singapore
| | - Isabelle Dusfour
- Unité d'Entomologie Médicale, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Kamaraju Raghavendra
- Insecticides and Insecticide Resistance Lab, National Institute of Malaria Research (ICMR), Delhi, India
| | - João Pinto
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Vincent Corbel
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Montpellier, France
| | - Jean-Philippe David
- Laboratoire d'Ecologie Alpine (LECA), Centre National de la Recherche Scientifique (CNRS), University Grenoble-Alpes (UGA), Grenoble, France
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Cory JS. Evolution of host resistance to insect pathogens. CURRENT OPINION IN INSECT SCIENCE 2017; 21:54-59. [PMID: 28822489 DOI: 10.1016/j.cois.2017.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
Insect pathogens are widely used as a tool for sustainable pest management. Their complex mode of action was thought to make them immune to the evolution of resistance; however, several examples of field-based resistance to the bacterium Bacillus thuringiensis and a granulovirus have been recorded. Here I review the scenarios where resistance has evolved and discuss the likelihood of it occurring in other entomopathogens. I highlight recent research on the factors which might influence the evolution of resistance to insect pathogens, including the role of pathogen diversity, host nutrition and transgenerational effects.
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Affiliation(s)
- Jenny S Cory
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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Vitorino LC, Bessa LA. Technological Microbiology: Development and Applications. Front Microbiol 2017; 8:827. [PMID: 28539920 PMCID: PMC5423913 DOI: 10.3389/fmicb.2017.00827] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/24/2017] [Indexed: 12/22/2022] Open
Abstract
Over thousands of years, modernization could be predicted for the use of microorganisms in the production of foods and beverages. However, the current accelerated pace of new food production is due to the rapid incorporation of biotechnological techniques that allow the rapid identification of new molecules and microorganisms or even the genetic improvement of known species. At no other time in history have microorganisms been so present in areas such as agriculture and medicine, except as recognized villains. Currently, however, beneficial microorganisms such as plant growth promoters and phytopathogen controllers are required by various agricultural crops, and many species are being used as biofactories of important pharmacological molecules. The use of biofactories does not end there: microorganisms have been explored for the synthesis of diverse chemicals, fuel molecules, and industrial polymers, and strains environmentally important due to their biodecomposing or biosorption capacity have gained interest in research laboratories and in industrial activities. We call this new microbiology Technological Microbiology, and we believe that complex techniques, such as heterologous expression and metabolic engineering, can be increasingly incorporated into this applied science, allowing the generation of new and improved products and services.
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Affiliation(s)
- Luciana C. Vitorino
- Laboratory of Agricultural Microbiology, Goiano Federal InstituteGoiás, Brazil
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Grilo ML, Vanstreels RET, Wallace R, García-Párraga D, Braga ÉM, Chitty J, Catão-Dias JL, Madeira de Carvalho LM. Malaria in penguins - current perceptions. Avian Pathol 2017; 45:393-407. [PMID: 27009571 DOI: 10.1080/03079457.2016.1149145] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Avian malaria is a mosquito-borne disease caused by protozoans of the genus Plasmodium, and it is considered one of the most important causes of morbidity and mortality in captive penguins, both in zoological gardens and rehabilitation centres. Penguins are known to be highly susceptible to this disease, and outbreaks have been associated with mortality as high as 50-80% of affected captive populations within a few weeks. The disease has also been reported in wild penguin populations, however, its impacts on the health and fitness of penguins in the wild is not clear. This review provides an overview of the aetiology, life cycle and epidemiology of avian malaria, and provides details on the strategies that can be employed for the diagnostic, treatment and prevention of this disease in captive penguins, discussing possible directions for future research.
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Affiliation(s)
- M L Grilo
- a Interdisciplinary Centre of Research in Animal Health (CIISA), Faculdade de Medicina Veterinária , Universidade de Lisboa , Lisboa , Portugal.,b Institute for Terrestrial and Aquatic Wildlife Research , University of Veterinary Medicine Hannover, Foundation , Buesum , Germany
| | - R E T Vanstreels
- c Laboratório de Patologia Comparada de Animais Selvagens, Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia , Universidade de São Paulo , São Paulo , Brazil
| | - R Wallace
- d Milwaukee County Zoo , Milwaukee , WI , USA
| | - D García-Párraga
- e Veterinary Services , Oceanografic Ciudad de las Artes y las Ciencias , Valencia , Spain
| | - É M Braga
- f Departamento de Parasitologia , Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte , Brazil
| | | | - J L Catão-Dias
- c Laboratório de Patologia Comparada de Animais Selvagens, Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia , Universidade de São Paulo , São Paulo , Brazil
| | - L M Madeira de Carvalho
- a Interdisciplinary Centre of Research in Animal Health (CIISA), Faculdade de Medicina Veterinária , Universidade de Lisboa , Lisboa , Portugal
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40
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Novakova E, Woodhams DC, Rodríguez-Ruano SM, Brucker RM, Leff JW, Maharaj A, Amir A, Knight R, Scott J. Mosquito Microbiome Dynamics, a Background for Prevalence and Seasonality of West Nile Virus. Front Microbiol 2017; 8:526. [PMID: 28421042 PMCID: PMC5378795 DOI: 10.3389/fmicb.2017.00526] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 03/13/2017] [Indexed: 11/13/2022] Open
Abstract
Symbiotic microbial communities augment host phenotype, including defense against pathogen carriage and infection. We sampled the microbial communities in 11 adult mosquito host species from six regions in southern Ontario, Canada over 3 years. Of the factors examined, we found that mosquito species was the largest driver of the microbiota, with remarkable phylosymbiosis between host and microbiota. Seasonal shifts of the microbiome were consistently repeated over the 3-year period, while region had little impact. Both host species and seasonal shifts in microbiota were associated with patterns of West Nile virus (WNV) in these mosquitoes. The highest prevalence of WNV, with a seasonal spike each year in August, was in the Culex pipiens/restuans complex, and high WNV prevalence followed a decrease in relative abundance of Wolbachia in this species. Indeed, mean temperature, but not precipitation, was significantly correlated with Wolbachia abundance. This suggests that at higher temperatures Wolbachia abundance is reduced leading to greater susceptibility to WNV in the subsequent generation of C. pipiens/restuans hosts. Different mosquito genera harbored significantly different bacterial communities, and presence or abundance of Wolbachia was primarily associated with these differences. We identified several operational taxonomic units (OTUs) of Wolbachia that drive overall microbial community differentiation among mosquito taxa, locations and timepoints. Distinct Wolbachia OTUs were consistently found to dominate microbiomes of Cx. pipiens/restuans, and of Coquilletidia perturbans. Seasonal fluctuations of several other microbial taxa included Bacillus cereus, Enterococcus, Methylobacterium, Asaia, Pantoea, Acinetobacter johnsonii, Pseudomonas, and Mycoplasma. This suggests that microbiota may explain some of the variation in vector competence previously attributed to local environmental processes, especially because Wolbachia is known to affect carriage of viral pathogens.
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Affiliation(s)
- Eva Novakova
- Faculty of Science, University of South BohemiaCeske Budejovice, Czechia.,Biology Centre of ASCR, Institute of ParasitologyCeske Budejovice, Czechia
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts BostonBoston, MA, USA
| | | | | | - Jonathan W Leff
- Cooperative Institute for Research in Environmental Sciences, University of ColoradoBoulder, CO, USA.,Department of Ecology and Evolutionary Biology, University of ColoradoBoulder, CO, USA
| | | | - Amnon Amir
- Department of Computer Science and Engineering, Center for Microbiome Innovation, University of California San DiegoLa Jolla, CA, USA
| | - Rob Knight
- Department of Computer Science and Engineering, Center for Microbiome Innovation, University of California San DiegoLa Jolla, CA, USA.,Department of Pediatrics, University of California San DiegoLa Jolla, CA, USA
| | - James Scott
- Sporometrics IncToronto, ON, Canada.,Division of Occupational and Environmental Health, Dalla Lana School of Public Health, University of TorontoToronto, ON, Canada
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41
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Guo R, Sun S, Liu B. Difference in leaf water use efficiency/photosynthetic nitrogen use efficiency of Bt-cotton and its conventional peer. Sci Rep 2016; 6:33539. [PMID: 27628897 PMCID: PMC5024321 DOI: 10.1038/srep33539] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 08/30/2016] [Indexed: 11/22/2022] Open
Abstract
This study is to test the effects of Bt gene introduction on the foliar water/nitrogen use efficiency in cotton. We measured leaf stomatal conductance, photosynthetic rate, and transpiration rate under light saturation condition at different stages of a conventional cultivar (zhongmian no. 16) and its counterpart Bt cultivar (zhongmian no. 30) that were cultured on three levels of fertilization, based on which leaf instantaneous water use efficiency was derived. Leaf nitrogen concentration was measured to calculate leaf photosynthetic nitrogen use efficiency, and leaf δ13C was used to characterize long term water use efficiency. Bt cultivar was found to have lower stomatal conductance, net photosynthetic rates and transpiration rates, but higher instantaneous and long time water use efficiency. In addition, foliar nitrogen concentration was found to be higher but net photosynthetic rate was lower in the mature leaves of Bt cultivar, which led to lower photosynthetic nitrogen use efficiency. This might result from the significant decrease of photosynthetic rate due to the decrease of stomatal conductance. In conclusion, our findings show that the introduction of Bt gene should significantly increase foliar water use efficiency but decrease leaf nitrogen use efficiency in cotton under no selective pressure.
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Affiliation(s)
- Ruqing Guo
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China.,School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Shucun Sun
- School of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Biao Liu
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing 210042, China
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42
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Alkhaibari AM, Carolino AT, Yavasoglu SI, Maffeis T, Mattoso TC, Bull JC, Samuels RI, Butt TM. Metarhizium brunneum Blastospore Pathogenesis in Aedes aegypti Larvae: Attack on Several Fronts Accelerates Mortality. PLoS Pathog 2016; 12:e1005715. [PMID: 27389584 PMCID: PMC4936676 DOI: 10.1371/journal.ppat.1005715] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/01/2016] [Indexed: 11/19/2022] Open
Abstract
Aedes aegypti is the vector of a wide range of diseases (e.g. yellow fever, dengue, Chikungunya and Zika) which impact on over half the world's population. Entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana have been found to be highly efficacious in killing mosquito larvae but only now are the underlying mechanisms for pathogenesis being elucidated. Recently it was shown that conidia of M. anisopliae caused stress induced mortality in Ae. aegypti larvae, a different mode of pathogenicity to that normally seen in terrestrial hosts. Blastospores constitute a different form of inoculum produced by this fungus when cultured in liquid media and although blastospores are generally considered to be more virulent than conidia no evidence has been presented to explain why. In our study, using a range of biochemical, molecular and microscopy methods, the infection process of Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores was investigated. It appears that the blastospores, unlike conidia, readily adhere to and penetrate mosquito larval cuticle. The blastospores are readily ingested by the larvae but unlike the conidia are able infect the insect through the gut and rapidly invade the haemocoel. The fact that pathogenicity related genes were upregulated in blastospores exposed to larvae prior to invasion, suggests the fungus was detecting host derived cues. Similarly, immune and defence genes were upregulated in the host prior to infection suggesting mosquitoes were also able to detect pathogen-derived cues. The hydrophilic blastospores produce copious mucilage, which probably facilitates adhesion to the host but do not appear to depend on production of Pr1, a cuticle degrading subtilisin protease, for penetration since protease inhibitors did not significantly alter blastospore virulence. The fact the blastospores have multiple routes of entry (cuticle and gut) may explain why this form of the inoculum killed Ae. aegypti larvae in a relatively short time (12-24hrs), significantly quicker than when larvae were exposed to conidia. This study shows that selecting the appropriate form of inoculum is important for efficacious control of disease vectors such as Ae. aegypti.
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Affiliation(s)
- Abeer M. Alkhaibari
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Aline T. Carolino
- Department of Entomology and Plant Pathology, State University of North Fluminense, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Sare I. Yavasoglu
- Department of Biology, Faculty of Arts & Sciences, Adnan Menderes University, Aydin, Turkey
| | - Thierry Maffeis
- College of Engineering, Swansea University, Swansea, United Kingdom
| | - Thalles C. Mattoso
- Department of Entomology and Plant Pathology, State University of North Fluminense, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - James C. Bull
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Richard I. Samuels
- Department of Entomology and Plant Pathology, State University of North Fluminense, Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Tariq M. Butt
- Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea, United Kingdom
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Stalinski R, Laporte F, Després L, Tetreau G. Alkaline phosphatases are involved in the response ofAedes aegyptilarvae to intoxication withBacillus thuringiensissubsp.israelensis Cry toxins. Environ Microbiol 2016; 18:1022-36. [DOI: 10.1111/1462-2920.13186] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Renaud Stalinski
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Frédéric Laporte
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Laurence Després
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
| | - Guillaume Tetreau
- Laboratoire d'Ecologie Alpine LECA UMR5553; Université Grenoble Alpes; F-38000 Grenoble France
- Laboratoire d'Ecologie Alpine LECA UMR5553; Centre National de la Recherche Scientifique; F-38000 Grenoble France
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Wirth MC, Walton WE, Federici BA. Evolution of Resistance in Culex quinquefasciatus (Say) Selected With a Recombinant Bacillus thuringiensis Strain-Producing Cyt1Aa and Cry11Ba, and the Binary Toxin, Bin, From Lysinibacillus sphaericus. JOURNAL OF MEDICAL ENTOMOLOGY 2015; 52:1028-1035. [PMID: 26336254 PMCID: PMC4668759 DOI: 10.1093/jme/tjv115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/17/2015] [Indexed: 06/05/2023]
Abstract
Fourth instars of Culex quinquefasciatus (Say) (Diptera: Culicidae) were selected with a recombinant bacterial strain synthesizing the mosquitocidal proteins from Lysinibacillus sphaericus (Bin) and Cry11Ba and Cyt1Aa from Bacillus thuringiensis. Selection was initiated in Generation 1 with a concentration of 0.04 μg/ml, which rose to a maximum selection concentration of 8.0 μg/ml in Generation 14, followed by an unexpected, rapid increase in mortality in Generation 15. Subsequently, a selection concentration of 0.8 μg/ml was determined to be survivable. During this same period, resistance rose to nearly 1,000-fold (by Generation 12) and declined to 18.8-fold in Generation 19. Resistance remained low and fluctuated between 5.3 and 7.3 up to Generation 66. The cross-resistance patterns and interactions among the component proteins were analyzed to identify possible causes of this unusual pattern of evolution. Poor activity in the mid-range concentrations and lower-than-expected synergistic interactions were identified as potential sources of the early resistance. These findings should be considered in the development of genetically engineered strains intended to control nuisance and vector mosquitoes.
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Affiliation(s)
- Margaret C Wirth
- Department of Entomology, University of California, Riverside, CA 92521.
| | - William E Walton
- Department of Entomology, University of California, Riverside, CA 92521
| | - Brian A Federici
- Department of Entomology, University of California, Riverside, CA 92521. Interdepartmental Graduate Programs in Microbiology, and Cell, Molecular and Developmental Biology, University of California, Riverside, CA 92521
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45
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Bonin A, Paris M, Frérot H, Bianco E, Tetreau G, Després L. The genetic architecture of a complex trait: Resistance to multiple toxins produced by Bacillus thuringiensis israelensis in the dengue and yellow fever vector, the mosquito Aedes aegypti. INFECTION GENETICS AND EVOLUTION 2015; 35:204-13. [PMID: 26238211 DOI: 10.1016/j.meegid.2015.07.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/24/2015] [Accepted: 07/31/2015] [Indexed: 12/29/2022]
Abstract
The bacterial insecticide Bacillus thuringiensis subsp. israelensis (Bti) is an increasingly popular alternative to chemical insecticides for controlling mosquito populations. Because Bti toxicity relies on the action of four main toxins, resistance to Bti is very likely a complex phenotype involving several genes simultaneously. Dissecting the underlying genetic basis thus requires associating a quantitative measure of resistance to genetic variation at many loci in a segregating population. Here, we undertake this task using the dengue and yellow fever vector, the mosquito Aedes aegypti, as a study model. We conducted QTL (Quantitative Trait Locus) and admixture mapping analyses on two controlled crosses and on an artificial admixed population, respectively, all obtained from resistant and susceptible lab strains. We detected 16 QTL regions, among which four QTLs were revealed by different analysis methods. These four robust QTLs explained altogether 29.2% and 62.2% of the total phenotypic variance in the two QTL crosses, respectively. They also all showed a dominant mode of action. In addition, we found six loci showing statistical association with Bti resistance in the admixed population. Five of the supercontigs highlighted in this study contained candidate genes as suggested by their function, or by prior evidence from expression and/or outlier analyses. These genomic regions are thus good starting points for fine mapping of resistance to Bti or functional analyses aiming at identifying the underlying genes and mutations. Moreover, for the purpose of this work, we built the first Ae. aegypti genetic map based on markers associated with genes expressed in larvae. This genetic map harbors 229 SNP markers mapped across the three chromosomes for a total length of 311.9cM. It brought to light several assembly discrepancies with the reference genome, suggesting a high level of genome plasticity in Ae. aegypti.
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Affiliation(s)
- Aurélie Bonin
- Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP53, 38041 Grenoble, France.
| | - Margot Paris
- Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP53, 38041 Grenoble, France
| | - Hélène Frérot
- Unité Evolution, Ecologie et Paléontologie, UMR-CNRS 8198, Université de Lille 1-Sciences et Technologies, 59655 Villeneuve d'Ascq, France
| | - Erica Bianco
- Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP53, 38041 Grenoble, France
| | - Guillaume Tetreau
- Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP53, 38041 Grenoble, France
| | - Laurence Després
- Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP53, 38041 Grenoble, France
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46
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Das D, Chatterjee S, Dangar TK. Characterization and Mosquitocidal Potential of the Soil Bacteria Aneurinibacillus aneurinilyticus Isolated from Burdwan, West Bengal, India. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s40011-015-0510-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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47
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Tetreau G, Stalinski R, David JP, Després L. Monitoring resistance to Bacillus thuringiensis subsp. israelensis in the field by performing bioassays with each Cry toxin separately. Mem Inst Oswaldo Cruz 2015; 108:894-900. [PMID: 24037105 PMCID: PMC3970644 DOI: 10.1590/0074-0276130155] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 04/10/2013] [Indexed: 02/04/2023] Open
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) is increasingly used worldwide for mosquito control and is the only larvicide used in the French Rhône-Alpes region since decades. The artificial selection of mosquitoes with field-persistent Bti collected in breeding sites from this region led to a moderate level of resistance to Bti, but to relatively high levels of resistance to individual Bti Cry toxins. Based on this observation, we developed a bioassay procedure using each Bti Cry toxin separately to detect cryptic Bti-resistance evolving in field mosquito populations. Although no resistance to Bti was detected in none of the three mosquito species tested (Aedes rusticus, Aedes sticticus and Aedes vexans), an increased tolerance to Cry4Aa (3.5-fold) and Cry11Aa toxins (8-fold) was found in one Ae. sticticus population compared to other populations of the same species, suggesting that resistance to Bti may be arising in this population. This study confirms previous works showing a lack of Bti resistance in field mosquito populations treated for decades with this bioinsecticide. It also provides a first panorama of their susceptibility status to individual Bti Cry toxins. In combination with bioassays with Bti, bioassays with separate Cry toxins allow a more sensitive monitoring of Bti-resistance in the field.
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48
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Després L, Stalinski R, Faucon F, Navratil V, Viari A, Paris M, Tetreau G, Poupardin R, Riaz MA, Bonin A, Reynaud S, David JP. Chemical and biological insecticides select distinct gene expression patterns in Aedes aegypti mosquito. Biol Lett 2014; 10:20140716. [PMID: 25540155 PMCID: PMC4298186 DOI: 10.1098/rsbl.2014.0716] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/26/2014] [Indexed: 12/20/2022] Open
Abstract
Worldwide evolution of mosquito resistance to chemical insecticides represents a major challenge for public health, and the future of vector control largely relies on the development of biological insecticides that can be used in combination with chemicals (integrated management), with the expectation that populations already resistant to chemicals will not become readily resistant to biological insecticides. However, little is known about the metabolic pathways affected by selection with chemical or biological insecticides. Here we show that Aedes aegypti, a laboratory mosquito strain selected with a biological insecticide (Bacillus thuringiensis israelensis, Bti) evolved increased transcription of many genes coding for endopeptidases while most genes coding for detoxification enzymes were under-expressed. By contrast, in strains selected with chemicals, genes encoding detoxification enzymes were mostly over-expressed. In all the resistant strains, genes involved in immune response were under-transcribed, suggesting that basal immunity might be a general adjustment variable to compensate metabolic costs caused by insecticide selection. Bioassays generally showed no evidence for an increased susceptibility of selected strains towards the other insecticide type, and all chemical-resistant strains were as susceptible to Bti as the unselected parent strain, which is a good premise for sustainable integrated management of mosquito populations resistant to chemicals.
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Affiliation(s)
- Laurence Després
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Renaud Stalinski
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Frédéric Faucon
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Vincent Navratil
- Pôle Rhône-Alpes de Bioinformatique, Université de Lyon, Lyon 69000, France
| | - Alain Viari
- INRIA Grenoble Rhône-Alpes, Montbonnot-Saint-Martin 38330, France
| | - Margot Paris
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Guillaume Tetreau
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Rodolphe Poupardin
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Muhammad Asam Riaz
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Aurélie Bonin
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Stéphane Reynaud
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
| | - Jean-Philippe David
- Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France CNRS, Laboratoire d'Ecologie Alpine UMR 5553, BP53, Grenoble 38041, France
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Després L, Stalinski R, Tetreau G, Paris M, Bonin A, Navratil V, Reynaud S, David JP. Gene expression patterns and sequence polymorphisms associated with mosquito resistance to Bacillus thuringiensis israelensis toxins. BMC Genomics 2014; 15:926. [PMID: 25341495 PMCID: PMC4223840 DOI: 10.1186/1471-2164-15-926] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/16/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Despite the intensive use of Bacillus thuringiensis israelensis (Bti) toxins for mosquito control, little is known about the long term effect of exposure to this cocktail of toxins on target mosquito populations. In contrast to the many cases of resistance to Bacillus thuringiensis Cry toxins observed in other insects, there is no evidence so far for Bti resistance evolution in field mosquito populations. High fitness costs measured in a Bti selected mosquito laboratory strain suggest that evolving resistance to Bti is costly. The aim of the present study was to identify transcription level and polymorphism variations associated with resistance to Bti toxins in the dengue vector Aedes aegypti. We used RNA sequencing (RNA-seq) for comparing a laboratory-selected strain showing elevated resistance to Bti toxins and its parental non-selected susceptible strain. As the resistant strain displayed two marked larval development phenotypes (slow and normal), each phenotype was analyzed separately in order to evidence potential links between resistance mechanisms and mosquito life-history traits. RESULTS A total of 12,458 genes were detected of which 844 were differentially transcribed between the resistant and susceptible strains. Polymorphism analysis revealed a total of 68,541 SNPs of which 12,571 SNPs exhibited more than 40% frequency difference between the resistant and susceptible strains, affecting 2,953 genes. Bti resistance is associated with changes in the transcription level of enzymes involved in detoxification and chitin metabolism. Among previously described Bti-toxin receptors, four alkaline phosphatases (ALPs) were differentially transcribed between resistant and susceptible larvae, and non-synonymous changes affected the protein sequence of one cadherin, six aminopeptidases (APNs) and four α-amylases. Other putative Cry receptors located in lipid rafts, such as flotillin and glycoside hydrolases, were under-transcribed and/or contained non-synonymous substitutions. Finally, immunity-related genes showed contrasted transcription and polymorphisms patterns between the two developmental resistant phenotypes, suggesting the existence of trade-offs between Bti-resistance, life-history traits and immunity. CONCLUSIONS The present study is the first to analyze the whole transcriptome of Bti-resistant mosquitoes by RNA-seq, shedding light on the importance of studying both transcription levels and sequence polymorphism variations to get a comprehensive view of insecticide resistance.
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Affiliation(s)
- Laurence Després
- Université Grenoble Alpes, Laboratoire d'Ecologie Alpine UMR5553, Grenoble, France.
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50
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Torres SM, Cruz NLND, Rolim VPDM, Cavalcanti MIDA, Alves LC, Silva Júnior VAD. Cumulative mortality of Aedes aegypti larvae treated with compounds. Rev Saude Publica 2014; 48:445-50. [PMID: 25119939 PMCID: PMC4203074 DOI: 10.1590/s0034-8910.2014048005022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 02/10/2014] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca
alternifolia, carapa guianensis essential oils and fermented
extract of Carica papaya against Aedes
aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each
experimental group using the third larval stage, which were exposed for 24h.
The groups were: positive control with industrial larvicide (BTI) in
concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds
of essential oils and fermented extract, 50.0% concentration (G1); treated
with compounds of essential oils and fermented extract, 25.0% concentration
(G2); treated with compounds of essential oils and fermented extract, 12.5%
concentration (G3); and negative control group using water (NC1) and using
dimethyl (NC2). The larvae were monitored every 60 min using direct
visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure
period, whereas there was 100% mortality in the PC1 and PC2 groups compared
to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in
the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta
indica, Melaleuca alternifolia, Carapa guianensis and fermented
extract of Carica papaya was efficient at all
concentrations. Therefore, it can be used in Aedes aegypti
Liverpool third larvae stage control programs.
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Affiliation(s)
| | | | - Vitor Pereira de Matos Rolim
- Laboratório de Doenças Parasitárias dos Animais Domésticos, Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Recife, PE, Brasil
| | - Maria Inês de Assis Cavalcanti
- Laboratório de Doenças Parasitárias dos Animais Domésticos, Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Recife, PE, Brasil
| | - Leucio Câmara Alves
- Laboratório de Doenças Parasitárias dos Animais Domésticos, Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Recife, PE, Brasil
| | - Valdemiro Amaro da Silva Júnior
- Laboratório de Histologia Animal, Departamento de Morfologia e Fisiologia Animal, Universidade Federal Rural de Pernambuco, Recife, PE, Brasil
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