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Chen CY, Oliver SV. The effect of larval exposure to acids and detergents on the life history of the major malaria vector Anopheles arabiensis Patton (Diptera: Culicidae). PEST MANAGEMENT SCIENCE 2024. [PMID: 38801202 DOI: 10.1002/ps.8189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024]
Abstract
BACKGROUND Anopheles arabiensis, a highly adaptable member of the Anopheles gambiae complex, poses a challenge for control efforts due to its outdoor biting and resting behaviour. Consequently, indoor insecticide-based control methods are ineffective against An. arabiensis. Furthermore, An. arabiensis are adapting to breeding in polluted waters, and may be contributing to residual malaria and malaria in urban areas. There have been some advances in understanding the effect of rural pollutants on Anopheles mosquitoes, but the effect of urban pollutants is poorly understood. Thus, in this study, the effect of acidic pollutants [nitric acid (HNO3) and hydrochloric acid (HCl)] and alkaline pollutants (phosphate-free and phosphate-containing detergent) on two laboratory-reared An. arabiensis strains - an insecticide susceptible strain (SENN) and an insecticide-resistant strain selected from SENN (SENN-DDT) - were determined. RESULTS The median lethal concentration (LC50) and larval exposure on larval development, adult longevity and insecticide tolerance were evaluated. Nitric acid and phosphate-containing detergent were found to be more toxic than HCl and phosphate-free detergent in terms of LC50 values. Detergent exposure (both phosphate-containing and phosphate-free) increased adult longevity of both strains. Nitric acid reduced larval development time in both SENN and SENN-DDT, whereas HCl reduced larval development time in SENN only. By contrast, both phosphate-containing and phosphate-free detergents increased larval development time of both strains. Furthermore, HNO3 and phosphate-containing detergent increased insecticide tolerance the most. CONCLUSION The two An. arabiensis strains responded to urban pollutants differently. Thus, this study provides insight into the adaptation of An. arabiensis to acidic and alkaline urban pollutants. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Chia-Yu Chen
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg, South Africa
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shüné V Oliver
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg, South Africa
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Fotso-Toguem Y, Tene-Fossog B, Mugenzi LMJ, Wondji MJ, Njiokou F, Ranson H, Wondji CS. Genetic Diversity of Cytochrome P450s CYP6M2 and CYP6P4 Associated with Pyrethroid Resistance in the Major Malaria Vectors Anopheles coluzzii and Anopheles gambiae from Yaoundé, Cameroon. Genes (Basel) 2022; 14:52. [PMID: 36672793 PMCID: PMC9858699 DOI: 10.3390/genes14010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Assessing the genetic diversity of metabolic resistance genes, such as cytochrome P450s, helps to understand the dynamics and evolution of resistance in the field. Here, we analyzed the polymorphisms of CYP6M2 and CYP6P4, associated with pyrethroid resistance in Anopheles coluzzii and Anopheles gambiae, to detect potential resistance markers. Field-caught resistant mosquitos and susceptible lab strains were crossed, and F4 was exposed to permethrin for 15 min and 90 min to discriminate highly susceptible (HS) and highly resistant (HR) mosquitos, respectively. Significant permethrin mortality reduction was observed after pre-exposure to PBO, suggesting the gene involvement of P450s. qPCR analysis revealed significant overexpression of CYP6M2 (FC = 19.57 [95% CI 13.96-25.18] for An. coluzzii; 10.16 [7.86-12.46] for An. gambiae) and CYP6P4 (FC = 6.73 [6.15-7.30] An. coluzzii; 23.62 [26.48-20.76] An. gambiae). Full-gene and ≈1 kb upstream were sequenced. For CYP6M2, the upstream region shows low diversity in HR and HS (overall Hd = 0.49, π = 0.018), whereas the full-gene shows allelic-variation but without evidence of ongoing selection. CYP6P4 upstream region showed a lower diversity in HR (Hd = 0.48) than HS (Hd = 0.86) of An. gambiae. These results highlighted that CYP6P4-associated resistance is potentially driven by modification in upstream region. However, further work is needed to determine the real causative variants that will help design rapid detection tools.
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Affiliation(s)
- Yvan Fotso-Toguem
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
| | - Billy Tene-Fossog
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
| | - Leon M. J. Mugenzi
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
| | - Murielle J. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
| | - Flobert Njiokou
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
| | - Charles S. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
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Nkahe DL, Kopya E, Djiappi-Tchamen B, Toussile W, Sonhafouo-Chiana N, Kekeunou S, Mimpfoundi R, Awono-Ambene P, Wondji CS, Antonio-Nkondjio C. Fitness cost of insecticide resistance on the life-traits of a Anopheles coluzzii population from the city of Yaoundé, Cameroon. Wellcome Open Res 2020; 5:171. [PMID: 33029560 PMCID: PMC7525343 DOI: 10.12688/wellcomeopenres.16039.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2020] [Indexed: 12/21/2022] Open
Abstract
Background: Pyrethroid resistance is rapidly expanding in
An. gambiae s.l. populations across Sub-Saharan Africa. Yet there is still not enough information on the fitness cost of insecticide resistance . In the present study, the fitness cost of insecticide resistance on
Anopheles coluzzii population from the city of Yaoundé was investigated.
Methods: A resistant
An. coluzzii colony was established from field collected mosquitoes resistant to both DDT and pyrethroid and selected for 12 generations with deltamethrin 0.05%. The Ngousso laboratory susceptible strain was used as control. A total of 100 females of each strain were blood fed and allowed for individual eggs laying, and then different life traits parameters such as fecundity, fertility, larval development time, emergence rate and longevity were measured. The TaqMan assay was used to screen for the presence of the L1014F and L1014S
kdr mutations. Results: Field collected mosquitoes from the F0 generation had a mortality rate of 2.05% for DDT, 34.16% for permethrin and 50.23% for deltamethrin. The mortality rate of the F12 generation was 30.48% for deltamethrin, 1.25% for permethrin and 0% for DDT. The number of eggs laid per female was lower in the resistant colony compared to the susceptible (p <0.0001). Insecticide resistant larvae were found with a significantly long larval development time (10.61±0.33 days) compare to susceptible (7.57±0.35 days). The number of emerging females was significantly high in the susceptible group compared to the resistant . The adults lifespan was also significantly high for susceptible (21.73±1.19 days) compared to resistant (14.63±0.68 days). Only the L1014F-
kdr allele was detected in resistant population.. Conclusion: The study suggests that pyrethroid resistance is likely associated with a high fitness cost on
An.coluzzii populations. The addition of new tools targeting specifically larval stages could improve malaria vectors control and insecticide resistance management.
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Affiliation(s)
- Diane Leslie Nkahe
- Malaria Research Laboratory, OCEAC, Yaoundé, Centre, PO Box 288, Cameroon.,Department of Animal Biology, University of Yaoundé 1, Yaoundé, Cameroon
| | - Edmond Kopya
- Malaria Research Laboratory, OCEAC, Yaoundé, Centre, PO Box 288, Cameroon.,Department of Animal Biology, University of Yaoundé 1, Yaoundé, Cameroon
| | - Borel Djiappi-Tchamen
- Malaria Research Laboratory, OCEAC, Yaoundé, Centre, PO Box 288, Cameroon.,Department of Animal Biology, University of Dschang, Dschang, Cameroon
| | | | - Nadege Sonhafouo-Chiana
- Malaria Research Laboratory, OCEAC, Yaoundé, Centre, PO Box 288, Cameroon.,Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Sevilor Kekeunou
- Department of Animal Biology, University of Yaoundé 1, Yaoundé, Cameroon
| | - Remy Mimpfoundi
- Department of Animal Biology, University of Yaoundé 1, Yaoundé, Cameroon
| | | | | | - Christophe Antonio-Nkondjio
- Malaria Research Laboratory, OCEAC, Yaoundé, Centre, PO Box 288, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Hunt CM, Collins CM, Benedict MQ. Measuring and reducing biofilm in mosquito rearing containers. Parasit Vectors 2020; 13:439. [PMID: 32878628 PMCID: PMC7466484 DOI: 10.1186/s13071-020-04315-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/24/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Mosquito rearing containers contain organic-rich water that nourishes numerous bacteria, some of which are capable of forming biofilms. Biofilm is broadly an extracellular polymeric matrix (EPS) in which living bacteria occur, and the accumulation of biofilm is possible during routine stock-keeping as most of these containers are re-used. Whether biofilm has an effect on the mosquito rearing is not a question that has been investigated, nor have measures to reduce biofilm in this context been systematically studied. METHODS We measured biofilm accumulation in standard rearing containers by staining with crystal violet and determining the OD using a spectrophotometer. We also treated rearing containers with 0.1% sodium hypochlorite to determine its effectiveness in reducing biofilm abundance. Lastly, we performed an analysis of the relationship between the occurrence of biofilm and the likelihood of microbial blooms that were associated with larval death during trials of larval diets. RESULTS We observed that soaking rearing containers overnight in 0.1% sodium hypochlorite greatly reduced biofilm, but we observed no relationship between the use of containers that had not been treated with bleach and subsequent microbial blooms. CONCLUSIONS Larva rearing leaves detectable biofilm. While we were unable to correlate microbial blooms with the presence of biofilm, as a precaution, we recommend that plastic containers that are re-used be treated with 0.1% sodium hypochlorite occasionally.
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Affiliation(s)
- Catherine M. Hunt
- Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, NE, Atlanta, GA 30329-4027 USA
| | - C. Matilda Collins
- Centre for Environmental Policy, Imperial College London, 16-18 Princes Gardens, London, SW7 1NE UK
| | - Mark Q. Benedict
- Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, NE, Atlanta, GA 30329-4027 USA
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Nkahe DL, Kopya E, Djiappi-Tchamen B, Toussile W, Sonhafouo-Chiana N, Kekeunou S, Mimpfoundi R, Awono-Ambene P, Wondji CS, Antonio-Nkondjio C. Fitness cost of insecticide resistance on the life-traits of a Anopheles coluzzii population from the city of Yaoundé, Cameroon. Wellcome Open Res 2020; 5:171. [DOI: 10.12688/wellcomeopenres.16039.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Pyrethroid resistance is rapidly expanding in An. gambiae s.l. populations across Sub-Saharan Africa. Yet there is still not enough information on the fitness cost of insecticide resistance . In the present study, the fitness cost of insecticide resistance on Anopheles coluzzii population from the city of Yaoundé was investigated. Methods: A resistant An. coluzzii colony was established from field collected mosquitoes resistant to both DDT and pyrethroid and selected for 12 generations with deltamethrin 0.05%. The Ngousso laboratory susceptible strain was used as control. A total of 100 females of each strain were blood fed and allowed for individual eggs laying, and then different life traits parameters such as fecundity, fertility, larval development time, emergence rate and longevity were measured. The TaqMan assay was used to screen for the presence of the L1014F and L1014S kdr mutations. Results: Field collected mosquitoes from the F0 generation had a mortality rate of 2.05% for DDT, 34.16% for permethrin and 50.23% for deltamethrin. The mortality rate of the F12 generation was 30.48% for deltamethrin, 1.25% for permethrin and 0% for DDT. The number of eggs laid per female was lower in the resistant colony compared to the susceptible (p <0.0001). Insecticide resistant larvae were found with a significantly long larval development time (10.61±0.33 days) compare to susceptible (7.57±0.35 days). The number of emerging females was significantly high in the susceptible group compared to the resistant . The adults lifespan was also significantly high for susceptible (21.73±1.19 days) compared to resistant (14.63±0.68 days). Only the L1014F-kdr allele was detected in resistant population.. Conclusion: The study suggests that pyrethroid resistance is likely associated with a high fitness cost on An.coluzzii populations. The addition of new tools targeting specifically larval stages could improve malaria vectors control and insecticide resistance management.
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Nchoutpouen E, Talipouo A, Djiappi-Tchamen B, Djamouko-Djonkam L, Kopya E, Ngadjeu CS, Doumbe-Belisse P, Awono-Ambene P, Kekeunou S, Wondji CS, Antonio-Nkondjio C. Culex species diversity, susceptibility to insecticides and role as potential vector of Lymphatic filariasis in the city of Yaoundé, Cameroon. PLoS Negl Trop Dis 2019; 13:e0007229. [PMID: 30943198 PMCID: PMC6464241 DOI: 10.1371/journal.pntd.0007229] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 04/15/2019] [Accepted: 02/10/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Culex species are widespread across Cameroon and responsible for high burden of nuisance in most urban settings. However, despite their high nuisance, they remain less studied compared to anophelines. The present study aimed to assess Culex species distribution, susceptibility to insecticide, bionomics and role in Lymphatic Filariasis (LF) transmission in the city of Yaoundé. METHODS Mosquito collections were conducted from March to December 2017 using Centre for Disease Control light traps (CDC-LT), human landing catches (HLC) and larval collections. Mosquitoes were identified using morphological identification keys. Mosquitoes from the Culex pipiens complex were further identified using Polymerase Chain Reaction (PCR) to assess the presence of sibling species. Bioassays were conducted with 2-5 day-old unfed females to assess mosquito susceptibility to DDT, permethrin, deltamethrin and bendiocarb following WHO guidelines. Dead, control and surviving mosquitoes from bioassays were screened by PCR to detect the presence of knockdown resistance (kdr) alleles. Pools of mosquitoes were examined by PCR to detect the presence of Wuchereria bancrofti. RESULTS A total of 197,956 mosquitoes belonging to thirteen species were collected. The density of mosquito collected varied according to the collection methods, districts and seasons. Culex quinquefasciatus emerged as the most abundant and the only species of the Culex pipiens complex in Yaoundé. Culex species were found breeding in different types of breeding sites including polluted and unpolluted sites. All Culex species including Cx antennatus, Cx duttoni, Cx perfuscus and Cx tigripes were found to be highly resistant to permethrin, deltamethrin and DDT. Culex quinquefasciatus was also found to be resistant to bendiocarb. A high frequency of the West Africa kdr allele was recorded in resistant Cx. quinquefasciatus. Out of the 247 pooled samples of 25 Culex spp. examined for the presence of Wuchereria bancrofti, none was found infected. CONCLUSION The study confirms the high adaptation of Culex species particularly Culex quinquefasciatus to the urban environment and no implication of this species in the transmission of LF in Yaoundé Cameroon. Culex species predominance in urban settings highlight potential transmission risk of West Nile and rift valley fever in Yaoundé.
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Affiliation(s)
- Elysee Nchoutpouen
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Abdou Talipouo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Borel Djiappi-Tchamen
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Landre Djamouko-Djonkam
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Edmond Kopya
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Carmene Sandra Ngadjeu
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Patricia Doumbe-Belisse
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | | | - Charles Sinclair Wondji
- Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, United Kingdom
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contreles Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, United Kingdom
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Matiya DJ, Philbert AB, Kidima W, Matowo JJ. Dynamics and monitoring of insecticide resistance in malaria vectors across mainland Tanzania from 1997 to 2017: a systematic review. Malar J 2019; 18:102. [PMID: 30914051 PMCID: PMC6434877 DOI: 10.1186/s12936-019-2738-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/20/2019] [Indexed: 11/22/2022] Open
Abstract
Background Malaria still claims substantial lives of individuals in Tanzania. Insecticide-treated nets (ITNs) and indoor residual spray (IRS) are used as major malaria vector control tools. These tools are facing great challenges from the rapid escalating insecticide resistance in malaria vector populations. This review presents the information on the dynamics and monitoring of insecticide resistance in malaria vectors in mainland Tanzania since 1997. The information is important to policy-makers and other vector control stakeholders to reflect and formulate new resistance management plans in the country. Methods Reviewed articles on susceptibility and mechanisms of resistance in malaria vectors to insecticides across mainland Tanzania were systematically searched from the following databases: PubMed, Google scholar, HINARI and AGORA. The inclusion criteria were articles published between 2000 and 2017, reporting susceptibility of malaria vectors to insecticides, mechanisms of resistance in the mainland Tanzania, involving field collected adult mosquitoes, and mosquitoes raised from the field collected larvae. Exclusion criteria were articles reporting insecticide resistance in larval bio-assays, laboratory strains, and unpublished data. Reviewed information include year of study, malaria vectors, insecticides, and study sites. This information was entered in the excel sheet and analysed. Results A total of 30 articles met the selection criteria. The rapid increase of insecticide resistance in the malaria vectors across the country was reported since year 2006 onwards. Insecticide resistance in Anopheles gambiae sensu lato (s.l.) was detected in at least one compound in each class of all recommended insecticide classes. However, the Anopheles funestus s.l. is highly resistant to pyrethroids and DDT. Knockdown resistance (kdr) mechanism in An. gambiae s.l. is widely studied in the country. Biochemical resistance by detoxification enzymes (P450s, NSE and GSTs) in An. gambiae s.l. was also recorded. Numerous P450s genes associated with metabolic resistance were over transcribed in An. gambiae s.l. collected from agricultural areas. However, no study has reported mechanisms of insecticide resistance in the An. funestus s.l. in the country. Conclusion This review has shown the dynamics and monitoring of insecticide resistance in malaria vector populations across mainland Tanzanian. This highlights the need for devising improved control approaches of the malaria vectors in the country.
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Affiliation(s)
- Deokary Joseph Matiya
- Dar es Salaam University College of Education (DUCE), P.O. Box 2329, Dar es Salaam, Tanzania. .,University of Dar es Salaam (UDSM), P.O. Box 35064, Dar es Salaam, Tanzania.
| | - Anitha B Philbert
- University of Dar es Salaam (UDSM), P.O. Box 35064, Dar es Salaam, Tanzania
| | - Winifrida Kidima
- University of Dar es Salaam (UDSM), P.O. Box 35064, Dar es Salaam, Tanzania
| | - Johnson J Matowo
- Kilimanjaro Christian Medical University College (KCMUCo), P.O. Box 2240, Moshi, Tanzania
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Antonio-Nkondjio C, Sonhafouo-Chiana N, Ngadjeu CS, Doumbe-Belisse P, Talipouo A, Djamouko-Djonkam L, Kopya E, Bamou R, Awono-Ambene P, Wondji CS. Review of the evolution of insecticide resistance in main malaria vectors in Cameroon from 1990 to 2017. Parasit Vectors 2017; 10:472. [PMID: 29017590 PMCID: PMC5635606 DOI: 10.1186/s13071-017-2417-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/01/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Malaria remains a major public health threat in Cameroon and disease prevention is facing strong challenges due to the rapid expansion of insecticide resistance in vector populations. The present review presents an overview of published data on insecticide resistance in the main malaria vectors in Cameroon to assist in the elaboration of future and sustainable resistance management strategies. METHODS A systematic search on mosquito susceptibility to insecticides and insecticide resistance in malaria vectors in Cameroon was conducted using online bibliographic databases including PubMed, Google and Google Scholar. From each peer-reviewed paper, information on the year of the study, mosquito species, susceptibility levels, location, insecticides, data source and resistance mechanisms were extracted and inserted in a Microsoft Excel datasheet. The data collected were then analysed for assessing insecticide resistance evolution. RESULTS Thirty-three scientific publications were selected for the analysis. The rapid evolution of insecticide resistance across the country was reported from 2000 onward. Insecticide resistance was highly prevalent in both An. gambiae (s.l.) and An. funestus. DDT, permethrin, deltamethrin and bendiocarb appeared as the most affected compounds by resistance. From 2000 to 2017 a steady increase in the prevalence of kdr allele frequency was noted in almost all sites in An. gambiae (s.l.), with the L1014F kdr allele being the most prevalent. Several detoxification genes (particularly P450 monooxygenase) were associated with DDT, pyrethroids and bendiocarb resistance. In An. funestus, resistance to DDT and pyrethroids was mainly attributed to the 119F-GSTe2 metabolic resistance marker and over-expression of P450 genes whereas the 296S-RDL mutation was detected in dieldrin-resistant An. funestus. CONCLUSIONS The review provides an update of insecticide resistance status in malaria vector populations in Cameroon and stresses the need for further actions to reinforce malaria control strategies in the coming years.
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Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | | | - C. S. Ngadjeu
- Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | | | - A. Talipouo
- Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | | | - E. Kopya
- Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - R. Bamou
- Faculty of Sciences, University of Dschang, Dschang, Cameroon
| | - P. Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
| | - Charles S. Wondji
- Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
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Antonio-Nkondjio C, Tene Fossog B, Kopya E, Poumachu Y, Menze Djantio B, Ndo C, Tchuinkam T, Awono-Ambene P, Wondji CS. Rapid evolution of pyrethroid resistance prevalence in Anopheles gambiae populations from the cities of Douala and Yaoundé (Cameroon). Malar J 2015; 14:155. [PMID: 25879950 PMCID: PMC4403825 DOI: 10.1186/s12936-015-0675-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/04/2015] [Indexed: 11/15/2022] Open
Abstract
Background The adaptation of malaria vectors to urban areas is becoming a serious challenge for malaria control. The study presents the evolution of pyrethroid resistance in mosquito populations from the cities of Douala and Yaoundé between 2010 and 2013. Methods Susceptibility tests to permethrin and deltamethrin were carried out with two- to four-day old unfed Anopheles gambiae sensu lato adults raised from larvae collected from the field. Mosquitoes resistant to permethrin and deltamethrin and control were screened to detect the presence of the kdr alleles using the TaqMan assays. Mosquitoes belonging to the An. gambiae complex were subjected to PCR assays designed for species and molecular forms identifications. The genomic region containing the upstream of intron-1 of the voltage-gated sodium channel was sequenced and compared between mosquitoes originating from different breeding habitats. Results Anopheles gambiae s.l. specimens collected from the city of Douala were all Anopheles coluzzii. In Yaoundé, both An. gambiae and An. coluzzii were recorded. A rapid decrease of mosquito mortality to permethrin and deltamethrin was recorded between 2010 and 2013 in the two cities. The mortality rate varied from 80.3 to 22.3% and 94.4 to 59.7% for permethrin and deltamethrin, respectively. Both kdr alleles L1014F and L1014S were recorded. The frequency of kdr alleles increased rapidly over the study period, varying from 44 to 88.9% in Yaoundé and from 68 to 81% in Douala. The sequencing of a 1,228 bp region of intro-1 of the voltage-gated sodium channel revealed the presence of five different haplotypes. A high number of these haplotypes were recorded in An. coluzzii samples. No evidence for a recent selective sweep on intron-1 sequence within samples originating from different breeding habitat was detected using Fu’s and Tajima Fs statistics. Conclusion The present study supports rapid evolution of pyrethroid resistance in vector populations from the cities of Douala and Yaoundé and calls for immediate action to fight against the increasing prevalence of pyrethroid-resistant mosquitoes.
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Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Billy Tene Fossog
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Faculty of Sciences, University of Yaoundé I, PO Box 337, Yaoundé, Cameroon.
| | - Edmond Kopya
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Faculty of Sciences, University of Yaoundé I, PO Box 337, Yaoundé, Cameroon.
| | - Yacouba Poumachu
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Malaria Research Unit of the Laboratory of Applied Biology and Ecology (MRU-LABEA), Department of Animal Biology, Faculty of Science of the University of Dschang, PO Box 067, Dschang, Cameroon.
| | - Benjamin Menze Djantio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Cyrille Ndo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon. .,Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. .,Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon.
| | - Timoléon Tchuinkam
- Malaria Research Unit of the Laboratory of Applied Biology and Ecology (MRU-LABEA), Department of Animal Biology, Faculty of Science of the University of Dschang, PO Box 067, Dschang, Cameroon.
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), PO Box 288, Yaoundé, Cameroon.
| | - Charles S Wondji
- Vector Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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