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Nkemngo FN, W G Raissa L, Nebangwa DN, Nkeng AM, Kengne A, Mugenzi LMJ, Fotso-Toguem YG, Wondji MJ, Shey RA, Nguiffo-Nguete D, Fru-Cho J, Ndo C, Njiokou F, Webster JP, Wanji S, Wondji CS. Epidemiology of malaria, schistosomiasis, and geohelminthiasis amongst children 3-15 years of age during the dry season in Northern Cameroon. PLoS One 2023; 18:e0288560. [PMID: 37523402 PMCID: PMC10389741 DOI: 10.1371/journal.pone.0288560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 06/29/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases frequently geographically overlap, most studies focus on mono-infection and general prevalence surveys without molecular analysis. The current study investigated the epidemiological determinants of malaria, schistosomiasis, and geohelminthiasis transmission among children in the North Region of Cameroon. METHODOLOGY School and pre-school children aged 3-15 year-of-age were enrolled from three communities in March 2021 using a community cross-sectional design. Capillary-blood samples were obtained, and each was examined for malaria parasites using rapid-diagnostic-test (RDT), microscopy, and PCR while hemoglobin level was measured using a hemoglobinometer. Stool samples were analyzed for Schistosoma mansoni, S. guineensis, and soil-transmitted-helminthiasis (STH) infections using the Kato Katz method, and urine samples were assessed for the presence of S. haematobium eggs (including hybrids) using the standard urine filtration technique. RESULT A malaria prevalence of 56% (277/495) was recorded by PCR as opposed to 31.5% (156/495) by microscopy and 37.8% (186/495) by RDT. Similarly, schistosomiasis was observed at prevalence levels of up to 13.3% (66/495) overall [S. haematobium (8.7%); S. mansoni (3.8%); mixed Sh/Sm (0.6%); mixed Sh/Sm/Sg (0.2%). Both infections were higher in males and the 3-9 year-of-age groups. A high frequency of PCR reported P. falciparum mono-infection of 81.9% (227/277) and mixed P. falciparum/P. malariae infection of 17.3% (48/277) was observed. Malaria-helminths co-infections were observed at 13.1% (65/495) with marked variation between P. falciparum/S. haematobium (50.8%, 33/65); P. falciparum/S. mansoni (16.9%, 11/65) and P. falciparum/Ascaris (9.2%, 6/65) (χ2 = 17.5, p = 0.00003). Anemia prevalence was 32.9% (163/495), categorically associated with P. falciparum (45.8%, 104/227), Pf/Sh (11.5%, 26/227), and Pf/Sm (3.9%, 9/227) polyparasitism. CONCLUSION Polyparasitism with malaria and helminth infections is common in school-aged children despite periodic long-lasting insecticide-treated nets (LLINs) distribution and regular school-based praziquantel (for schistosomiasis) and albendazole (for STH) campaigns. Co-existence of Plasmodium parasites and helminths infections notably Schistosoma species among children may concurrently lead to an increase in Plasmodium infection with an enhanced risk of anemia, highlighting the necessity of an integrated approach for disease control interventions.
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Affiliation(s)
- Francis N Nkemngo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Lymen W G Raissa
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Derrick N Nebangwa
- Faculty of Life Science and Medicine, King's College London, New Hunt's House, London, United Kingdom
| | - Asongha M Nkeng
- Centre for Infection Biology and Translational Research (CIBiT), Forzi Institute, Buea, Cameroon
- Department of Sociology & Anthropology, Faculty of Social and Management Sciences, University of Buea, Buea, Cameroon
| | - Alvine Kengne
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Robert A Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | | | - Jerome Fru-Cho
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Cyrille Ndo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Parasitology and Ecology Laboratory, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Joanne P Webster
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Herts, United Kingdom
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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Mugenzi LMJ, A. Tekoh T, S. Ibrahim S, Muhammad A, Kouamo M, Wondji MJ, Irving H, Hearn J, Wondji CS. The duplicated P450s CYP6P9a/b drive carbamates and pyrethroids cross-resistance in the major African malaria vector Anopheles funestus. PLoS Genet 2023; 19:e1010678. [PMID: 36972302 PMCID: PMC10089315 DOI: 10.1371/journal.pgen.1010678] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 04/11/2023] [Accepted: 02/23/2023] [Indexed: 03/29/2023] Open
Abstract
Cross-resistance to insecticides in multiple resistant malaria vectors is hampering resistance management. Understanding its underlying molecular basis is critical to implementation of suitable insecticide-based interventions. Here, we established that the tandemly duplicated cytochrome P450s, CYP6P9a/b are driving carbamate and pyrethroid cross-resistance in Southern African populations of the major malaria vector Anopheles funestus. Transcriptome sequencing revealed that cytochrome P450s are the most over-expressed genes in bendiocarb and permethrin-resistant An. funestus. The CYP6P9a and CYP6P9b genes are overexpressed in resistant An. funestus from Southern Africa (Malawi) versus susceptible An. funestus (Fold change (FC) is 53.4 and 17 respectively), while the CYP6P4a and CYP6P4b genes are overexpressed in resistant An. funestus in Ghana, West Africa, (FC is 41.1 and 17.2 respectively). Other up-regulated genes in resistant An. funestus include several additional cytochrome P450s (e.g. CYP9J5, CYP6P2, CYP6P5), glutathione-S transferases, ATP-binding cassette transporters, digestive enzymes, microRNA and transcription factors (FC<7). Targeted enrichment sequencing strongly linked a known major pyrethroid resistance locus (rp1) to carbamate resistance centering around CYP6P9a/b. In bendiocarb resistant An. funestus, this locus exhibits a reduced nucleotide diversity, significant p-values when comparing allele frequencies, and the most non-synonymous substitutions. Recombinant enzyme metabolism assays showed that both CYP6P9a/b metabolize carbamates. Transgenic expression of CYP6P9a/b in Drosophila melanogaster revealed that flies expressing both genes were significantly more resistant to carbamates than controls. Furthermore, a strong correlation was observed between carbamate resistance and CYP6P9a genotypes with homozygote resistant An. funestus (CYP6P9a and the 6.5kb enhancer structural variant) exhibiting a greater ability to withstand bendiocarb/propoxur exposure than homozygote CYP6P9a_susceptible (e.g Odds ratio = 20.8, P<0.0001 for bendiocarb) and heterozygotes (OR = 9.7, P<0.0001). Double homozygote resistant genotype (RR/RR) were even more able to survive than any other genotype combination showing an additive effect. This study highlights the risk that pyrethroid resistance escalation poses to the efficacy of other classes of insecticides. Available metabolic resistance DNA-based diagnostic assays should be used by control programs to monitor cross-resistance between insecticides before implementing new interventions.
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Affiliation(s)
- Leon M. J. Mugenzi
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Theofelix A. Tekoh
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry and Molecular Biology, Faculty of Science University of Buea, Buea, Cameroon
| | - Sulaiman S. Ibrahim
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Department of Biochemistry, Bayero University, Kano, Nigeria
| | - Abdullahi Muhammad
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Mersimine Kouamo
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Murielle J. Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College, An Lòchran, 10 Inverness Campus, Inverness, Scotland, United Kingdom
| | - Charles S. Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Mugenzi LMJ, Akosah-Brempong G, Tchouakui M, Menze BD, Tekoh TA, Tchoupo M, Nkemngo FN, Wondji MJ, Nwaefuna EK, Osae M, Wondji CS. Escalating pyrethroid resistance in two major malaria vectors Anopheles funestus and Anopheles gambiae (s.l.) in Atatam, Southern Ghana. BMC Infect Dis 2022; 22:799. [PMID: 36284278 PMCID: PMC9597992 DOI: 10.1186/s12879-022-07795-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/15/2022] [Indexed: 11/10/2022] Open
Abstract
Background Aggravation of insecticide resistance in malaria vectors is threatening the efforts to control malaria by reducing the efficacy of insecticide-based interventions hence needs to be closely monitored. This study investigated the intensity of insecticide resistance of two major malaria vectors An. funestus sensu stricto (s.s.) and An. gambiae sensu lato (s.l.) collected in southern Ghana and assessed the bio-efficacy of several long-lasting insecticidal nets (LLINs) against these mosquito populations. Methods The insecticide susceptibility profiles of Anopheles funestus s.s. and Anopheles gambiae s.l. populations from Obuasi region (Atatam), southern Ghana were characterized and the bio-efficacy of some LLINs was assessed to determine the impact of insecticide resistance on the effectiveness of these tools. Furthermore, molecular markers associated with insecticide resistance in both species were characterized in the F0 and F1 populations using PCR and qPCR methods. Results Anopheles funestus s.s. was the predominant species and was resistant to pyrethroids, organochlorine and carbamate insecticides, but fully susceptible to organophosphates. An. gambiae s.l. was resistant to all four insecticide classes. High intensity of resistance to 5 × and 10 × the discriminating concentration (DC) of pyrethroids was observed in both species inducing a considerable loss of efficacy of long-lasting insecticidal nets (LLINs). Temporal expression analysis revealed a massive 12-fold increase in expression of the CYP6P4a cytochrome P450 gene in An. funestus s.s., initially from a fold change of 41 (2014) to 500 (2021). For both species, the expression of candidate genes did not vary according to discriminating doses. An. gambiae s.l. exhibited high frequencies of target-site resistance including Vgsc-1014F (90%) and Ace-1 (50%) while these mutations were absent in An. funestus s.s. Conclusions The multiple and high intensity of resistance observed in both malaria vectors highlights the need to implement resistance management strategies and the introduction of new insecticide chemistries. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07795-4.
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Affiliation(s)
- Leon M. J. Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Gabriel Akosah-Brempong
- grid.8652.90000 0004 1937 1485African Regional Postgraduate Program in Insect Science, University of Ghana, Legon, Accra, Ghana ,grid.512980.7Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, Accra, Ghana
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Benjamin D. Menze
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Theofelix A. Tekoh
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Francis N. Nkemngo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Murielle J. Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon ,grid.48004.380000 0004 1936 9764Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Ekene K. Nwaefuna
- grid.512980.7Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, Accra, Ghana
| | - Michael Osae
- grid.512980.7Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, Accra, Ghana
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon ,grid.48004.380000 0004 1936 9764Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
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Menze BD, Tchouakui M, Mugenzi LMJ, Tchapga W, Tchoupo M, Wondji MJ, Chiumia M, Mzilahowa T, Wondji CS. Marked aggravation of pyrethroid resistance in major malaria vectors in Malawi between 2014 and 2021 is partly linked with increased expression of P450 alleles. BMC Infect Dis 2022; 22:660. [PMID: 35907831 PMCID: PMC9338535 DOI: 10.1186/s12879-022-07596-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/27/2022] [Indexed: 11/10/2022] Open
Abstract
Background Increased intensity of pyrethroid resistance is threatening the effectiveness of insecticide-based interventions to control malaria in Africa. Assessing the extent of this aggravation and its impact on the efficacy of these tools is vital to ensure the continued control of major vectors. Here we took advantage of 2009 and 2014 data from Malawi to establish the extent of the resistance escalation in 2021 and assessed its impact on various bed nets performance. Methods Indoor blood-fed and wild female Anopheles (An) mosquitoes were collected with an electric aspirator in Chikwawa. Cocktail and SINE PCR were used to identify sibling species belonging to An. funestus group and An. gambiae complex. The susceptibility profile to the four classes of insecticides was assessed using the WHO tubes bioassays. Data were saved in an Excel file. Analysis was done using Vassarstats and figures by Graph Pad. Results In this study, a high level of resistance was observed with pyrethroids (permethrin, deltamethrin and alpha-cypermethrin with mortality rate at 5x discriminating concentration (DC) < 50% and Mortality rate at 10x DC < 70%). A high level of resistance was also observed to carbamate (bendiocarb) with mortality rate at 5x DC < 25%). Aggravation of resistance was also noticed between 2009 and 2021. For pyrethroids, the mortality rate for permethrin reduced from 47.2% in 2009 to 13% in 2014 and 6.7% in 2021. For deltamethrin, the mortality rate reduced from 42.3% in 2009 to 1.75% in 2014 and 5.2% in 2021. For Bendiocarb, the mortality rate reduced from 60% in 2009 to 30.1% in 2014 and 12.2% in 2021. The high resistance observed is consistent with a drastic loss of pyrethroid-only bed nets efficacy although Piperonyl butoxide (PBO)-based nets remain effective. The resistance pattern observed was linked with high up-regulation of the P450 genes CYP6P9a, CYP6P9b and CYP6M7 in An. funestus s.s. mosquitoes surviving exposure to deltamethrin at 1x, 5x and 10x DC. A significant association was observed between the 6.5 kb structural variant and resistance escalation with homozygote resistant (SV+/SV+) more likely to survive exposure to 5x and 10x (OR = 4.1; P < 0.001) deltamethrin than heterozygotes. However, a significant proportion of mosquitoes survived the synergist assays with PBO suggesting that other mechanisms than P450s are present. Conclusions This resistance aggravation in An. funestus s.s. Malawian population highlights an urgent need to deploy novel control tools not relying on pyrethroids to improve the effectiveness of vector control. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07596-9.
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Affiliation(s)
- Benjamin D Menze
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon.
| | - Magellan Tchouakui
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Leon M J Mugenzi
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Williams Tchapga
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Micareme Tchoupo
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Murielle J Wondji
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon.,Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Martin Chiumia
- Malaria Alert Centre (MAC), Kamuzu University of Health Sciences (KUHeS), Blantyre, Malawi
| | - Themba Mzilahowa
- Malaria Alert Centre (MAC), Kamuzu University of Health Sciences (KUHeS), Blantyre, Malawi
| | - Charles S Wondji
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon. .,Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Menze BD, Mugenzi LMJ, Tchouakui M, Wondji MJ, Tchoupo M, Wondji CS. Experimental Hut Trials Reveal That CYP6P9a/b P450 Alleles Are Reducing the Efficacy of Pyrethroid-Only Olyset Net against the Malaria Vector Anopheles funestus but PBO-Based Olyset Plus Net Remains Effective. Pathogens 2022; 11:pathogens11060638. [PMID: 35745492 PMCID: PMC9228255 DOI: 10.3390/pathogens11060638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/12/2022] [Accepted: 05/19/2022] [Indexed: 02/04/2023] Open
Abstract
Malaria remains a major public health concern in Africa. Metabolic resistance in major malaria vectors such as An. funestus is jeopardizing the effectiveness of long-lasting insecticidal nets (LLINs) to control malaria. Here, we used experimental hut trials (EHTs) to investigate the impact of cytochrome P450-based resistance on the efficacy of PBO-based net (Olyset Plus) compared to a permethrin-only net (Olyset), revealing a greater loss of efficacy for the latter. EHT performed with progenies of F5 crossing between the An. funestus pyrethroid-resistant strain FUMOZ and the pyrethroid-susceptible strain FANG revealed that PBO-based nets (Olyset Plus) induced a significantly higher mortality rate (99.1%) than pyrethroid-only nets (Olyset) (56.7%) (p < 0.0001). The blood-feeding rate was higher in Olyset compared to Olyset Plus (11.6% vs. 5.6%; p = 0.013). Genotyping the CYP6P9a/b and the intergenic 6.5 kb structural variant (SV) resistance alleles showed that, for both nets, homozygote-resistant mosquitoes have a greater ability to blood-feed than the susceptible mosquitoes. Homozygote-resistant genotypes significantly survived more with Olyset after cone assays (e.g., CYP6P9a OR = 34.6; p < 0.0001) than homozygote-susceptible mosquitoes. A similar but lower correlation was seen with Olyset Plus (OR = 6.4; p < 0.001). Genotyping EHT samples confirmed that CYP6P9a/b and 6.5 kb_SV homozygote-resistant mosquitoes survive and blood-feed significantly better than homozygote-susceptible mosquitoes when exposed to Olyset. Our findings highlight the negative impact of P450-based resistance on pyrethroid-only nets, further supporting that PBO nets, such as Olyset Plus, are a better solution in areas of P450-mediated resistance to pyrethroids.
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Affiliation(s)
- Benjamin D. Menze
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK;
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
- Correspondence: (B.D.M.); (C.S.W.)
| | - Leon M. J. Mugenzi
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
| | - Magellan Tchouakui
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
| | - Murielle J. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK;
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
| | - Micareme Tchoupo
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
| | - Charles S. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK;
- Medical Entomology Department, Centre for Research in Infectious Diseases (CRID), Yaoundé 13591, Cameroon; (L.M.J.M.); (M.T.); (M.T.)
- Correspondence: (B.D.M.); (C.S.W.)
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Nkemngo FN, Mugenzi LMJ, Tchouakui M, Nguiffo-Nguete D, Wondji MJ, Mbakam B, Tchoupo M, Ndo C, Wanji S, Wondji CS. Xeno-monitoring of molecular drivers of artemisinin and partner drug resistance in P. falciparum populations in malaria vectors across Cameroon. Gene 2022; 821:146339. [PMID: 35183684 PMCID: PMC8942117 DOI: 10.1016/j.gene.2022.146339] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 01/29/2023]
Abstract
High Plasmodium infection rate in the major Anopheles vectors across Cameroon. Emerging signal of the R575I polymorphism in the k13 propeller domain backbone. Dominance of the N86F184mdr1 variants in natural P. falciparum populations. Low k13 and mdr1 genetic diversity in P. falciparum-infected mosquitoes.
Background Monitoring of drug resistance in Plasmodium populations is crucial for malaria control. This has primarily been performed in humans and rarely in mosquitoes where parasites genetic recombination occurs. Here, we characterized the Plasmodium spp populations in wild Anopheles vectors by analyzing the genetic diversity of the P. falciparum kelch13 and mdr1 gene fragments implicated in artemisinin and partner drug resistance across Cameroon in three major malaria vectors. Methods Anopheles mosquitoes were collected across nine localities in Cameroon and dissected into the head/thorax (H/T) and abdomen (Abd) after species identification. A TaqMan assay was performed to detect Plasmodium infection. Fragments of the Kelch 13 and mdr1 genes were amplified in P. falciparum positive samples and directly sequenced to assess their drug resistance polymorphisms and genetic diversity profile. Results The study revealed a high Plasmodium infection rate in the major Anopheles vectors across Cameroon. Notably, An. funestus vector recorded the highest sporozoite (8.0%) and oocyst (14.4%) infection rates. A high P. falciparum sporozoite rate (80.08%) alongside epidemiological signatures of significant P. malariae (15.9%) circulation were recorded in these vectors. Low genetic diversity with six (A578S, R575I, G450R, L663L, G453D, N458D) and eight (H53H, V62L, V77E, N86Y, G102G, L132I, H143H, Y184F) point mutations were observed in the k13 and mdr1 backbones respectively. Remarkably, the R575I (4.4%) k13 and Y184F (64.2%) mdr1 mutations were the predominant variants in the P. falciparum populations. Conclusion The emerging signal of the R575I polymorphism in the Pfk13 propeller backbone entails the regular surveillance of molecular markers to inform evidence-based policy decisions. Moreover, the high frequency of the 86N184F allele highlights concerns on the plausible decline in efficacy of artemisinin-combination therapies (ACTs); further implying that parasite genotyping from mosquitoes can provide a more relevant scale for quantifying resistance epidemiology in the field.
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Affiliation(s)
- Francis N Nkemngo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon; Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Daniel Nguiffo-Nguete
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
| | - Bertrand Mbakam
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Cyrille Ndo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon; Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon.
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon; Research Foundation in Tropical Diseases and Environment, Buea, Cameroon.
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon; Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom.
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8
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Tchouakui M, Mugenzi LMJ, Wondji MJ, Tchoupo M, Njiokou F, Wondji CS. A 6.5kb Intergenic Structural Variation Exacerbates the Fitness Cost of P450-Based Metabolic Resistance in the Major African Malaria Vector Anopheles funestus. Genes (Basel) 2022; 13:genes13040626. [PMID: 35456432 PMCID: PMC9025909 DOI: 10.3390/genes13040626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/18/2022] [Accepted: 03/25/2022] [Indexed: 11/16/2022] Open
Abstract
Metabolic-based resistance to insecticides limit the control of medically important pests, and it is extremely detrimental in the ongoing struggle to control disease vectors. Elucidating the fitness cost of metabolic resistance in major malaria vectors is vital for successful resistance management. We established the fitness cost of the 6.5kb structural variant (6.5kb-sv) between the duplicated CYP6P9a/b P450s using the hybrid strain generated from the crossing between two An. funestus laboratory strains. Furthermore, we assessed the cumulative impact of this marker with the duplicated P450 genes. We established that individuals that were homozygote for the resistant structural variant (SV) presented reduced fecundity and slow development relative to those that were homozygote for the susceptible SV. Furthermore, we observed that 6.5kb act additively with CYP6P9a and CYP6P9b to exacerbate the reduced fecundity and the increased development time of resistant mosquitoes since double/triple homozygote susceptible (SS/SS/SS) significantly laid more eggs and developed faster than other genotypes. Moreover, a restoration of susceptibility was noted over 10 generations in the insecticide-free environment with an increased proportion of susceptible individuals. This study highlights the negative impact of multiple P450-based resistance on the key physiological traits of malaria vectors. Such high fitness costs suggest that in the absence of selection pressure, the resistant individuals will be outcompeted in the field. Therefore, this should encourage future strategies based on the rotation of insecticides to reduce selection pressure and to slow the spread of pyrethroid resistance.
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Affiliation(s)
- Magellan Tchouakui
- Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon; (L.M.J.M.); (M.J.W.); (M.T.)
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon;
- Correspondence: (M.T.); (C.S.W.)
| | - Leon M. J. Mugenzi
- Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon; (L.M.J.M.); (M.J.W.); (M.T.)
- Department of Biochemistry and Molecular Biology, Faculty of Science University of Buea, Buea P.O. Box 63, Cameroon
| | - Murielle J. Wondji
- Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon; (L.M.J.M.); (M.J.W.); (M.T.)
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon; (L.M.J.M.); (M.J.W.); (M.T.)
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon;
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon; (L.M.J.M.); (M.J.W.); (M.T.)
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Correspondence: (M.T.); (C.S.W.)
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9
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Wondji CS, Hearn J, Irving H, Wondji MJ, Weedall G. RNAseq-based gene expression profiling of the Anopheles funestus pyrethroid-resistant strain FUMOZ highlights the predominant role of the duplicated CYP6P9a/b cytochrome P450s. G3 (Bethesda) 2022; 12:jkab352. [PMID: 34718535 PMCID: PMC8727960 DOI: 10.1093/g3journal/jkab352] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/10/2021] [Indexed: 12/04/2022]
Abstract
Insecticide-based interventions, notably long-lasting insecticidal nets, against mosquito vectors of malaria are currently threatened by pyrethroid resistance. Here, we contrasted RNAseq-based gene expression profiling of laboratory-resistant (FUMOZ) and susceptible (FANG) strains of the major malaria vector Anopheles funestus. Cytochrome P450 genes were the predominant over-expressed detoxification genes in FUMOZ, with high expression of the duplicated CYP6P9a (fold-change of 82.23 vs FANG) and CYP6P9b (FC 11.15). Other over-expressed P450s belonged to the same cluster of P450s corresponding to the resistance to pyrethroid 1 (rp1) quantitative trait loci (QTL) on chromosome 2R. Several Epsilon class glutathione S-transferases were also over-expressed in FUMOZ, as was the ATP-binding cassette transporter AFUN019220 (ABCA) which also exhibited between-strain alternative splicing events at exon 7. Significant differences in single-nucleotide polymorphism frequencies between strains occurred in resistance QTLs rp1 (CYP6P9a/b and CYP6AA1), rp2 on chromosome 2L (CYP6Z1, CYP6M7, and CYP6Z3), and rp3 on chromosome 3R (CYP9J5, CYP9J4, and CYP9J3). Differences were also detected in CYP4G17 and CYP4G16 genes on the X chromosome, both of which are associated with cuticular resistance in Anopheles gambiae. A close analysis of nonsynonymous diversity at the CYP6P9a/b loci revealed a drastic loss of diversity in FUMOZ with only a single polymorphism and 2 haplotypes vs 18 substitutions and 8 haplotypes in FANG. By contrast, a lowly expressed cytochrome P450 (CYP4C36) did not exhibit diversity differences between strains. We also detected the known pyrethroid resistance conferring amino acid change N384S in CYP6P9b. This study further elucidates the molecular bases of resistance in An. funestus, informing strategies to better manage widespread resistance across Africa.
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Affiliation(s)
- Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, P.O. Box 1359, Cameroon
- Entomology Unit, International Institute of Tropical Agriculture (IITA), Yaoundé, P.O. Box 2008, Cameroon
| | - Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Murielle J Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), Yaoundé, P.O. Box 1359, Cameroon
| | - Gareth Weedall
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 3AF, UK
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10
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Wamba ANR, Ibrahim SS, Kusimo MO, Muhammad A, Mugenzi LMJ, Irving H, Wondji MJ, Hearn J, Bigoga JD, Wondji CS. The cytochrome P450 CYP325A is a major driver of pyrethroid resistance in the major malaria vector Anopheles funestus in Central Africa. Insect Biochem Mol Biol 2021; 138:103647. [PMID: 34530119 DOI: 10.1016/j.ibmb.2021.103647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/20/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
The overexpression and overactivity of key cytochrome P450s (CYP450) genes are major drivers of metabolic resistance to insecticides in African malaria vectors such as Anopheles funestus s.s. Previous RNAseq-based transcription analyses revealed elevated expression of CYP325A specific to Central African populations but its role in conferring resistance has not previously been demonstrated. In this study, RT-qPCR consistently confirmed that CYP325A is highly over-expressed in pyrethroid-resistant An. funestus from Cameroon, compared with a control strain and insecticide-unexposed mosquitoes. A synergist bioassay with PBO significantly recovered susceptibility for permethrin and deltamethrin indicating P450-based metabolic resistance. Analyses of the coding sequence of CYP325A Africa-wide detected high-levels of polymorphism, but with no predominant alleles selected by pyrethroid resistance. Geographical amino acid changes were detected notably in Cameroon. In silico homology modelling and molecular docking simulations predicted that CYP325A binds and metabolises type I and type II pyrethroids. Heterologous expression of recombinant CYP325A and metabolic assays confirmed that the most-common Cameroonian haplotype metabolises both type I and type II pyrethroids with depletion rate twice that the of the DR Congo haplotype. Analysis of the 1 kb putative promoter of CYP325A revealed reduced diversity in resistant mosquitoes compared to susceptible ones, suggesting a potential selective sweep in this region. The establishment of CYP325A as a pyrethroid resistance metabolising gene further explains pyrethroid resistance in Central African populations of An. funestus. Our work will facilitate future efforts to detect the causative resistance markers in the promoter region of CYP325A to design field applicable DNA-based diagnostic tools.
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Affiliation(s)
- Amelie N R Wamba
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Faculty of Science, Department of Biochemistry, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
| | - Sulaiman S Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK; Department of Biochemistry, Bayero University, PMB, 3011, Kano, Nigeria.
| | - Michael O Kusimo
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon.
| | - Abdullahi Muhammad
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK; Centre for Biotechnology Research, Bayero University, Kano, PMB, 3011, Kano Nigeria.
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK.
| | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK.
| | - Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK.
| | - Jude D Bigoga
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK; Laboratory for Vector Biology and Control, National Reference Unit for Vector Control, The Biotechnology Centre, Nkolbisson - University of Yaoundé I, P.O. Box 3851, Messa, Yaoundé, Cameroon.
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK.
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11
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Tchouakui M, Mugenzi LMJ, Wondji MJ, Tchoupo M, Njiokou F, Wondji CS. Combined over-expression of two cytochrome P450 genes exacerbates the fitness cost of pyrethroid resistance in the major African malaria vector Anopheles funestus. Pestic Biochem Physiol 2021; 173:104772. [PMID: 33771251 PMCID: PMC8024743 DOI: 10.1016/j.pestbp.2021.104772] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/26/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Metabolic resistance driven by multiple P450 genes is worsening insecticide resistance in malaria vectors. However, it remains unclear whether such multiple over-expression imposes an additive fitness cost in the vectors. Here, we showed that two highly over-expressed P450 genes (CYP6P9a and CYP6P9b) combine to impose additive fitness costs in pyrethroid-resistant Anopheles funestus. Genotyping of the CYP6P9b resistance allele in hybrid mosquitoes from a pyrethroid-resistant FUMOZ-R and the susceptible FANG strains revealed that this gene imposes a fitness cost in resistant mosquitoes similar to CYP6P9a. Homozygote susceptible CYP6P9b_S (SS) significantly lay more eggs than the resistant (OR = 2.2, P = 0.04) and with greater hatching rate (p < 0.04). Homozygote resistant larvae CYP6P9b_R (RR) developed significantly slower than homozygote susceptible from L1-L4 (χ2 = 7.2; P = 0.007) with a late pupation observed for RR compared to both heterozygotes and homozygotes susceptible (χ2 = 11.17; P = 0.0008). No difference was observed between genotypes for adult longevity with no change in allele frequency and gene expression across the lifespan. Furthermore, we established that CYP6P9b combines with CYP6P9a to additively exacerbate the fitness cost of pyrethroid resistance with a greater reduction in fecundity/fertility and increased developmental time of double homozygote resistant mosquitoes. Moreover, an increased proportion of double homozygote susceptible individuals was noted over 10 generations in the insecticide-free environment (χ2 = 6.3; P = 0.01) suggesting a reversal to susceptibility in the absence of selection. Such greater fitness cost imposed by multiple P450 genes shows that resistance management strategy based on rotation could help slow the spread of resistance.
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Affiliation(s)
- Magellan Tchouakui
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, P.O. Box 812, University of Yaoundé 1, Yaoundé, Cameroon.
| | - Leon M J Mugenzi
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
| | - Murielle J Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA Liverpool, UK.
| | - Micareme Tchoupo
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, P.O. Box 812, University of Yaoundé 1, Yaoundé, Cameroon
| | - Charles S Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon; Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA Liverpool, UK.
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12
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Gueye OK, Tchouakui M, Dia AK, Faye MB, Ahmed AA, Wondji MJ, Nguiffo DN, J. Mugenzi LM, Tripet F, Konaté L, Diabate A, Dia I, Gaye O, Faye O, Niang EHA, S. Wondji C. Insecticide Resistance Profiling of Anopheles coluzzii and Anopheles gambiae Populations in the Southern Senegal: Role of Target Sites and Metabolic Resistance Mechanisms. Genes (Basel) 2020; 11:E1403. [PMID: 33255805 PMCID: PMC7760107 DOI: 10.3390/genes11121403] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/05/2020] [Accepted: 11/20/2020] [Indexed: 12/22/2022] Open
Abstract
The emergence and spread of insecticide resistance among the main malaria vectors is threatening the effectiveness of vector control interventions in Senegal. The main drivers of this resistance in the Anopheles gambiae complex (e.g., An. gambiae and Anopheles coluzzii) remains poorly characterized in Senegal. Here we characterized the main target site and metabolic resistances mechanisms among the An. gambiae and An. coluzzii populations from their sympatric and allopatric or predominance area in Senegal. Larvae and pupae of An. gambiae s.l. were collected, reared to adulthood, and then used for insecticides susceptibility and synergist assays using the WHO (World Health Organisation) test kits for adult mosquitoes. The TaqMan method was used for the molecular characterization of the main target site insecticide resistance mechanisms (Vgsc-1014F, Vgsc-1014S, N1575Y and G119S). A RT-qPCR (Reverse Transcriptase-quantitative Polymerase Chaine Reaction) was performed to estimate the level of genes expression belonging to the CYP450 (Cytochrome P450) family. Plasmodium infection rate was investigated using TaqMan method. High levels of resistance to pyrethroids and DDT and full susceptibility to organophosphates and carbamates where observed in all three sites, excepted a probable resistance to bendiocarb in Kedougou. The L1014F, L1014S, and N1575Y mutations were found in both species. Pre-exposure to the PBO (Piperonyl butoxide) synergist induced a partial recovery of susceptibility to permethrin and full recovery to deltamethrin. Subsequent analysis of the level of genes expression, revealed that the CYP6Z1 and CYP6Z2 genes were over-expressed in wild-resistant mosquitoes compared to the reference susceptible strain (Kisumu), suggesting that both the metabolic resistance and target site mutation involving kdr mutations are likely implicated in this pyrethroid resistance. The presence of both target-site and metabolic resistance mechanisms in highly pyrethroid-resistant populations of An. gambiae s.l. from Senegal threatens the effectiveness and the sustainability of the pyrethroid-based tools and interventions currently deployed in the country. The Kdr-west mutation is widely widespread in An. coluzzii sympatric population. PBO or Duo nets and IRS (Indoor Residual Spraying) with organophosphates could be used as an alternative measure to sustain malaria control in the study area.
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Affiliation(s)
- Oumou. K. Gueye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Abdoulaye K. Dia
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Mouhamed B. Faye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Amblat A. Ahmed
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Murielle J. Wondji
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Daniel N. Nguiffo
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Leon. M. J. Mugenzi
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme ST5 5BG, UK;
| | - Lassana Konaté
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Abdoulaye Diabate
- Centre Muraz/Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso BP 545, Burkina Faso;
| | - Ibrahima Dia
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, Dakar BP 220, Senegal;
| | - Oumar Gaye
- Service de Parasitologie-Mycologie, Faculté de Médecine, Pharmacie et d’Odontologie, Université Cheikh Anta Diop, Dakar BP 5005, Senegal;
| | - Ousmane Faye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - El Hadji A. Niang
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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13
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Djuicy DD, Hearn J, Tchouakui M, Wondji MJ, Irving H, Okumu FO, Wondji CS. CYP6P9-Driven Signatures of Selective Sweep of Metabolic Resistance to Pyrethroids in the Malaria Vector Anopheles funestus Reveal Contemporary Barriers to Gene Flow. Genes (Basel) 2020; 11:E1314. [PMID: 33167550 PMCID: PMC7694540 DOI: 10.3390/genes11111314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/24/2020] [Accepted: 10/31/2020] [Indexed: 11/16/2022] Open
Abstract
Pyrethroid resistance in major malaria vectors such as Anopheles funestus threatens malaria control efforts in Africa. Cytochrome P450-mediated metabolic resistance is best understood for CYP6P9 genes in southern Africa in An. funestus. However, we do not know if this resistance mechanism is spreading across Africa and how it relates to broader patterns of gene flow across the continent. Nucleotide diversity of the CYP6P9a gene and the diversity pattern of five gene fragments spanning a region of 120 kb around the CYP6P9a gene were surveyed in mosquitoes from southern, eastern and central Africa. These analyses revealed that a Cyp6P9a resistance-associated allele has swept through southern and eastern Africa and is now fixed in these regions. A similar diversity profile was observed when analysing genomic regions located 34 kb upstream to 86 kb downstream of the CYP6P9a locus, concordant with a selective sweep throughout the rp1 locus. We identify reduced gene flow between southern/eastern Africa and central Africa, which we hypothesise is due to the Great Rift Valley. These potential barriers to gene flow are likely to prevent or slow the spread of CYP6P9-based resistance mechanism to other parts of Africa and would to be considered in future vector control interventions such as gene drive.
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Affiliation(s)
- Delia Doreen Djuicy
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591 Yaoundé, Cameroon; (M.T.); (M.J.W.)
| | - Jack Hearn
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (H.I.)
| | - Magellan Tchouakui
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591 Yaoundé, Cameroon; (M.T.); (M.J.W.)
| | - Murielle J. Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591 Yaoundé, Cameroon; (M.T.); (M.J.W.)
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (H.I.)
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (H.I.)
| | - Fredros O. Okumu
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, PO Box 53 Ifakara 67501, Tanzania;
| | - Charles S. Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591 Yaoundé, Cameroon; (M.T.); (M.J.W.)
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (J.H.); (H.I.)
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14
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Nkemngo FN, Mugenzi LMJ, Terence E, Niang A, Wondji MJ, Tchoupo M, Nguete ND, Tchapga W, Irving H, Ntabi JDM, Agonhossou R, Boussougou-Sambe TS, Akoton RB, Koukouikila-Koussounda F, Pinilla YT, Ntoumi F, Djogbenou LS, Ghogomu SM, Ndo C, Adegnika AA, Borrmann S, Wondji CS. Multiple insecticide resistance and Plasmodium infection in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon. Wellcome Open Res 2020; 5:146. [PMID: 33204845 PMCID: PMC7667521 DOI: 10.12688/wellcomeopenres.15818.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms. Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a locality situated 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adults. Bioassays were performed to assess resistance profile to the four insecticides classes. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated. Results: Anopheles funestus s.s. was the most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having similar sporozoite rate. Both species exhibited high levels of resistance to the pyrethroids, permethrin and deltamethrin (<40% mortality). An. gambiae s.s. was resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively . Furthermore, the high pyrethroid/DDT resistances in An. gambiae corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b. Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the significant Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.
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Affiliation(s)
- Francis N. Nkemngo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, South West, 237, Cameroon
| | - Leon M. J. Mugenzi
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Ebai Terence
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Abdoulaye Niang
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Murielle J. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Micareme Tchoupo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Nguiffo D. Nguete
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Williams Tchapga
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jacques D. M. Ntabi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Romuald Agonhossou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Terence S. Boussougou-Sambe
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Romaric B. Akoton
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Felix Koukouikila-Koussounda
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Yudi T. Pinilla
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Luc S. Djogbenou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Stephen M. Ghogomu
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Cyrille Ndo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Ayola A. Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- Eberhard Karls Universität Tübingen,, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Charles S. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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15
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Mugenzi LMJ, Menze BD, Tchouakui M, Wondji MJ, Irving H, Tchoupo M, Hearn J, Weedall GD, Riveron JM, Cho-Ngwa F, Wondji CS. A 6.5-kb intergenic structural variation enhances P450-mediated resistance to pyrethroids in malaria vectors lowering bed net efficacy. Mol Ecol 2020; 29:4395-4411. [PMID: 32974960 DOI: 10.1111/mec.15645] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 09/01/2020] [Indexed: 01/21/2023]
Abstract
Elucidating the complex evolutionary armory that mosquitoes deploy against insecticides is crucial to maintain the effectiveness of insecticide-based interventions. Here, we deciphered the role of a 6.5-kb structural variation (SV) in driving cytochrome P450-mediated pyrethroid resistance in the malaria vector, Anopheles funestus. Whole-genome pooled sequencing detected an intergenic 6.5-kb SV between duplicated CYP6P9a/b P450s in pyrethroid-resistant mosquitoes through a translocation event. Promoter analysis revealed a 17.5-fold higher activity (p < .0001) for the SV- carrying fragment than the SV- free one. Quantitative real-time PCR expression profiling of CYP6P9a/b for each SV genotype supported its role as an enhancer because SV+/SV+ homozygote mosquitoes had a significantly greater expression for both genes than heterozygotes SV+/SV- (1.7- to 2-fold) and homozygotes SV-/SV- (4-to 5-fold). Designing a PCR assay revealed a strong association between this SV and pyrethroid resistance (SV+/SV+ vs. SV-/SV-; odds ratio [OR] = 2,079.4, p < .001). The 6.5-kb SV is present at high frequency in southern Africa (80%-100%) but absent in East/Central/West Africa. Experimental hut trials revealed that homozygote SV mosquitoes had a significantly greater chance to survive exposure to pyrethroid-treated nets (OR 27.7; p < .0001) and to blood feed than susceptible mosquitoes. Furthermore, mosquitoes homozygote-resistant at the three loci (SV+/CYP6P9a_R/CYP6P9b_R) exhibited a higher resistance level, leading to a far superior ability to survive exposure to nets than those homozygotes susceptible at the three loci, revealing a strong additive effect. This study highlights the important role of structural variations in the development of insecticide resistance in malaria vectors and their detrimental impact on the effectiveness of pyrethroid-based nets.
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Affiliation(s)
- Leon M J Mugenzi
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Benjamin D Menze
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Murielle J Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Gareth D Weedall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,School of Natural Sciences and Psychology, Liverpool, John Moores University, Liverpool, UK
| | - Jacob M Riveron
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Fidelis Cho-Ngwa
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
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16
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Tchouakui M, Riveron Miranda J, Mugenzi LMJ, Djonabaye D, Wondji MJ, Tchoupo M, Tchapga W, Njiokou F, Wondji CS. Correction: Cytochrome P450 metabolic resistance (CYP6P9a) to pyrethroids imposes a fitness cost in the major African malaria vector Anopheles funestus. Heredity (Edinb) 2020; 125:371. [PMID: 32879464 PMCID: PMC7554042 DOI: 10.1038/s41437-020-00360-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon. .,Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon.
| | - Jacob Riveron Miranda
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Doumani Djonabaye
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Pharmacology and Toxicology Laboratory, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Williams Tchapga
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon. .,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK.
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17
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Nkemngo FN, Mugenzi LMJ, Terence E, Niang A, Wondji MJ, Tchoupo M, Nguete ND, Tchapga W, Irving H, Ntabi JDM, Agonhossou R, Boussougou-Sambe TS, Akoton RB, Koukouikila-Koussounda F, Pinilla YT, Ntoumi F, Djogbenou LS, Ghogomu SM, Ndo C, Adegnika AA, Borrmann S, Wondji CS. Elevated Plasmodium sporozoite infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon. Wellcome Open Res 2020; 5:146. [PMID: 33204845 PMCID: PMC7667521 DOI: 10.12688/wellcomeopenres.15818.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2020] [Indexed: 11/13/2023] Open
Abstract
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms. Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a village located 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adult progeny. Bioassays were performed to assess resistance profile to insecticides. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated. Results: Anopheles funestus s.s. was most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having a similar sporozoite rate. Both species exhibited high levels of resistance to pyrethroids (<40% mortality). An. gambiae s.s. was also resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively . Furthermore, the high pyrethroid/DDT resistances in An. gambiae s.s. corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b. Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the high Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.
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Affiliation(s)
- Francis N. Nkemngo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, South West, 237, Cameroon
| | - Leon M. J. Mugenzi
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Ebai Terence
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Abdoulaye Niang
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Murielle J. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Micareme Tchoupo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Nguiffo D. Nguete
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Williams Tchapga
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jacques D. M. Ntabi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Romuald Agonhossou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Terence S. Boussougou-Sambe
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Romaric B. Akoton
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Felix Koukouikila-Koussounda
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Yudi T. Pinilla
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Luc S. Djogbenou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Stephen M. Ghogomu
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Cyrille Ndo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Ayola A. Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- Eberhard Karls Universität Tübingen,, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Charles S. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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18
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Weedall GD, Mugenzi LMJ, Menze BD, Tchouakui M, Ibrahim SS, Amvongo-Adjia N, Irving H, Wondji MJ, Tchoupo M, Djouaka R, Riveron JM, Wondji CS. A cytochrome P450 allele confers pyrethroid resistance on a major African malaria vector, reducing insecticide-treated bednet efficacy. Sci Transl Med 2020; 11:11/484/eaat7386. [PMID: 30894503 DOI: 10.1126/scitranslmed.aat7386] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 10/09/2018] [Indexed: 11/02/2022]
Abstract
Metabolic resistance to insecticides such as pyrethroids in mosquito vectors threatens control of malaria in Africa. Unless it is managed, recent gains in reducing malaria transmission could be lost. To improve monitoring and assess the impact of insecticide resistance on malaria control interventions, we elucidated the molecular basis of pyrethroid resistance in the major African malaria vector, Anopheles funestus We showed that a single cytochrome P450 allele (CYP6P9a_R) in A. funestus reduced the efficacy of insecticide-treated bednets for preventing transmission of malaria in southern Africa. Expression of key insecticide resistance genes was detected in populations of this mosquito vector throughout Africa but varied according to the region. Signatures of selection and adaptive evolutionary traits including structural polymorphisms and cis-regulatory transcription factor binding sites were detected with evidence of selection due to the scale-up of insecticide-treated bednet use. A cis-regulatory polymorphism driving the overexpression of the major resistance gene CYP6P9a allowed us to design a DNA-based assay for cytochrome P450-mediated resistance to pyrethroid insecticides. Using this assay, we tracked the spread of pyrethroid resistance and found that it was almost fixed in mosquitoes from southern Africa but was absent from mosquitoes collected elsewhere in Africa. Furthermore, a field study in experimental huts in Cameroon demonstrated that mosquitoes carrying the resistance CYP6P9a_R allele survived and succeeded in blood feeding more often than did mosquitoes that lacked this allele. Our findings highlight the need to introduce a new generation of insecticide-treated bednets for malaria control that do not rely on pyrethroid insecticides.
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Affiliation(s)
- Gareth D Weedall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.,School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool L3 3AF, U.K
| | - Leon M J Mugenzi
- LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Benjamin D Menze
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.,LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Magellan Tchouakui
- LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Sulaiman S Ibrahim
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.,Department of Biochemistry, Bayero University, PMB 3011, Kano, Nigeria
| | - Nathalie Amvongo-Adjia
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.,Centre for Medical Research, Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 13033, Yaoundé, Cameroon
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Murielle J Wondji
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.,LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Micareme Tchoupo
- LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Rousseau Djouaka
- International Institute of Tropical Agriculture (IITA), Cotonou 08 BP 0932, Benin
| | - Jacob M Riveron
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.,LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Charles S Wondji
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK. .,LSTM Research Unit at the Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
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Tchouakui M, Riveron Miranda J, Mugenzi LMJ, Djonabaye D, Wondji MJ, Tchoupo M, Tchapga W, Njiokou F, Wondji CS. Cytochrome P450 metabolic resistance (CYP6P9a) to pyrethroids imposes a fitness cost in the major African malaria vector Anopheles funestus. Heredity (Edinb) 2020; 124:621-632. [PMID: 32157181 DOI: 10.1038/s41437-020-0304-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/10/2023] Open
Abstract
Metabolic resistance threatens the sustainability of pyrethroid-based malaria control interventions. Elucidating the fitness cost and potential reversal of metabolic resistance is crucial to design suitable resistance management strategies. Here, we deciphered the fitness cost associated with the CYP6P9a (P450-mediated metabolic resistance) in the major African malaria vector Anopheles funestus. Reciprocal crosses were performed between a pyrethroid susceptible (FANG) and resistant (FUMOZ-R) laboratory strains and the hybrid strains showed intermediate resistance. Genotyping the CYP6P9a-R resistance allele in oviposited females revealed that CYP6P9a negatively impacts the fecundity as homozygote susceptible mosquitoes (CYP6P9a-SS) lay more eggs than heterozygote (OR = 2.04: P = 0.01) and homozygote resistant mosquitoes. CYP6P9a also imposes a significant fitness cost on the larval development as homozygote resistant larvae (CYP6P9a-RR) developed significantly slower than heterozygote and homozygote susceptible mosquitoes (χ2 = 11.2; P = 0.0008). This fitness cost was further supported by the late pupation of homozygote resistant than susceptible mosquitoes (OR = 2.50; P < 0.01). However, CYP6P9a does not impact the longevity as no difference was observed in the life span of mosquitoes with different genotypes (χ2 = 1.6; P = 0.9). In this hybrid strain, a significant decrease of the resistant CYP6P9a-RR genotype was observed after ten generations (χ2 = 6.6; P = 0.01) suggesting a reversal of P450-based resistance in the absence of selection. This study shows that the P450-mediated metabolic resistance imposes a high fitness cost in malaria vectors supporting that a resistance management strategy based on rotation could help mitigate the impact of such resistance.
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Affiliation(s)
- Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon. .,Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon.
| | - Jacob Riveron Miranda
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Leon M J Mugenzi
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Doumani Djonabaye
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Pharmacology and Toxicology Laboratory, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Murielle J Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Williams Tchapga
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13501, Yaoundé, Cameroon. .,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK.
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20
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Ibrahim SS, Fadel AN, Tchouakui M, Terence E, Wondji MJ, Tchoupo M, Kérah-Hinzoumbé C, Wanji S, Wondji CS. High insecticide resistance in the major malaria vector Anopheles coluzzii in Chad Republic. Infect Dis Poverty 2019; 8:100. [PMID: 31796068 PMCID: PMC6892245 DOI: 10.1186/s40249-019-0605-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 11/01/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Sahel region of Chad Republic is a prime candidate for malaria pre-elimination. To facilitate pre-elimination efforts in this region, two populations of Anopheles coluzzii from Central Chad Republic were characterized, their insecticide resistance profile and the possible molecular mechanisms driving the resistance in the field investigated. METHODS Bloodfed female Anopheles gambiae s.l. resting indoor, were collected at N'djamena and Massakory, Chad in 2018 and characterized for species composition, and infection rate was determined using the TaqMan assay. Susceptibility to various insecticides was assessed using WHO tube bioassays. Cone bioassays were conducted using various long-lasting insecticidal nets (LLINs). Results were analysed using Chi Square test. Knockdown resistance (kdr) and ace-1 markers were investigated by TaqMan genotyping. RESULTS Anopheles coluzzii was the major vector found in N'djamena (100%) and Massakory (~ 94%). No Plasmodium was found in 147 bloodfed F0 An. coluzzii (82 from N'djamena and 65 from Massakory). High intensity pyrethroid resistance was observed with mortalities of < 2% for permethrin, deltamethrin and etofenprox, and with < 50% and < 60% dead following exposure to 10× diagnostic doses of deltamethrin and permethrin, respectively. For both sites, < 10% mortalities were observed with DDT. Synergist bioassays with piperonylbutoxide significantly recovered pyrethroid susceptibility in Massakory populations, implicating CYP450s (mortality = 13.6% for permethrin, χ2 = 22.8, df = 1, P = 0.0006; mortality = 13.0% for deltamethrin, χ2 = 8.8, df = 1, P < 0.00031). Cone-bioassays established complete loss of efficacy of the pyrethroid-based LLINs; and a 100% recovery of susceptibility following exposure to the roof of PermaNet®3.0, containing piperonylbutoxide. Both populations were susceptible to malathion, but high bendiocarb resistance was observed in Massakory population. The absence of ace-1 mutation points to the role of metabolic resistance in the bendiocarb resistance. Both 1014F and 1014S mutations were found in both populations at around 60% and < 20% respectively. Sequencing of intron-1 of the voltage-gated sodium channel revealed a low genetic diversity suggesting reduced polymorphism. CONCLUSIONS Multiple resistance in An. coluzzii populations from Chad highlight challenges associated with deployment of LLINs and indoor residual spraying (IRS) in the Sahel of this country. The pyrethroid-synergists LLINs (e.g. PermaNet®3.0) and organophosphate-based IRS maybe the alternatives for malaria control in this region.
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Affiliation(s)
- Sulaiman S. Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5 QA UK
- Department of Biochemistry, Bayero University, Kano, PMB 3011 Nigeria
| | - Amen N. Fadel
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
- Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
| | - Ebai Terence
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
| | - Murielle J. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5 QA UK
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
| | | | - Samuel Wanji
- Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Charles S. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5 QA UK
- Centre for Research in Infectious Diseases (CRID), LSTM Research Unit, P.O. Box 13591, Yaoundé, Cameroon
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21
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Mugenzi LMJ, Menze BD, Tchouakui M, Wondji MJ, Irving H, Tchoupo M, Hearn J, Weedall GD, Riveron JM, Wondji CS. Cis-regulatory CYP6P9b P450 variants associated with loss of insecticide-treated bed net efficacy against Anopheles funestus. Nat Commun 2019; 10:4652. [PMID: 31604938 PMCID: PMC6789023 DOI: 10.1038/s41467-019-12686-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/21/2019] [Indexed: 11/09/2022] Open
Abstract
Elucidating the genetic basis of metabolic resistance to insecticides in malaria vectors is crucial to prolonging the effectiveness of insecticide-based control tools including long lasting insecticidal nets (LLINs). Here, we show that cis-regulatory variants of the cytochrome P450 gene, CYP6P9b, are associated with pyrethroid resistance in the African malaria vector Anopheles funestus. A DNA-based assay is designed to track this resistance that occurs near fixation in southern Africa but not in West/Central Africa. Applying this assay we demonstrate, using semi-field experimental huts, that CYP6P9b-mediated resistance associates with reduced effectiveness of LLINs. Furthermore, we establish that CYP6P9b combines with another P450, CYP6P9a, to additively exacerbate the reduced efficacy of insecticide-treated nets. Double homozygote resistant mosquitoes (RR/RR) significantly survive exposure to insecticide-treated nets and successfully blood feed more than other genotypes. This study provides tools to track and assess the impact of multi-gene driven metabolic resistance to pyrethroids, helping improve resistance management. Bed nets treated with insecticides have been instrumental in reducing malaria mortality, but insecticide resistance is on the rise. Here, Mugenzi et al. identify genetic variants in the P450 gene CYP6P9b of Anopheles funestus that associate with insecticide resistance and develop a PCR-based diagnostic assay to help identify pyrethroid-resistant strains.
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Affiliation(s)
- Leon M J Mugenzi
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon.,Department of Biochemistry and Molecular Biology, Faculty of Science University of Buea, P.O. Box, 63, Buea, Cameroon
| | - Benjamin D Menze
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon
| | - Murielle J Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon
| | - Jack Hearn
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Gareth D Weedall
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,School of Natural Sciences and Psychology, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
| | - Jacob M Riveron
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. .,Centre for Research in Infectious Diseases (CRID), P.O. Box, 13501, Yaoundé, Cameroon.
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22
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Riveron JM, Huijben S, Tchapga W, Tchouakui M, Wondji MJ, Tchoupo M, Irving H, Cuamba N, Maquina M, Paaijmans K, Wondji CS. Escalation of Pyrethroid Resistance in the Malaria Vector Anopheles funestus Induces a Loss of Efficacy of Piperonyl Butoxide-Based Insecticide-Treated Nets in Mozambique. J Infect Dis 2019; 220:467-475. [PMID: 30923819 PMCID: PMC6603977 DOI: 10.1093/infdis/jiz139] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/26/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Insecticide resistance poses a serious threat to insecticide-based interventions in Africa. There is a fear that resistance escalation could jeopardize malaria control efforts. Monitoring of cases of aggravation of resistance intensity and its impact on the efficacy of control tools is crucial to predict consequences of resistance. METHODS The resistance levels of an Anopheles funestus population from Palmeira, southern Mozambique, were characterized and their impact on the efficacy of various insecticide-treated nets established. RESULTS A dramatic loss of efficacy of all long-lasting insecticidal nets (LLINs), including piperonyl butoxide (PBO)-based nets (Olyset Plus), was observed. This An. funestus population consistently (2016, 2017, and 2018) exhibited a high degree of pyrethroid resistance. Molecular analyses revealed that this resistance escalation was associated with a massive overexpression of the duplicated cytochrome P450 genes CYP6P9a and CYP6P9b, and also the fixation of the resistance CYP6P9a_R allele in this population in 2016 (100%) in contrast to 2002 (5%). However, the low recovery of susceptibility after PBO synergist assay suggests that other resistance mechanisms could be involved. CONCLUSIONS The loss of efficacy of pyrethroid-based LLINs with and without PBO is a concern for the effectiveness of insecticide-based interventions, and action should be taken to prevent the spread of such super-resistance.
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Affiliation(s)
- Jacob M Riveron
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), United Kingdom
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Silvie Huijben
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe
- ISGlobal, Barcelona, Spain
| | - Williams Tchapga
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | | | - Murielle J Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), United Kingdom
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Micareme Tchoupo
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Helen Irving
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), United Kingdom
| | | | - Mara Maquina
- Centro de Investigação em Saúde da Manhiça, Mozambique
| | - Krijn Paaijmans
- Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe
- ISGlobal, Barcelona, Spain
- Centro de Investigação em Saúde da Manhiça, Mozambique
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), United Kingdom
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
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23
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Fadel AN, Ibrahim SS, Tchouakui M, Terence E, Wondji MJ, Tchoupo M, Wanji S, Wondji CS. A combination of metabolic resistance and high frequency of the 1014F kdr mutation is driving pyrethroid resistance in Anopheles coluzzii population from Guinea savanna of Cameroon. Parasit Vectors 2019; 12:263. [PMID: 31133042 PMCID: PMC6537440 DOI: 10.1186/s13071-019-3523-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The scale-up in the distribution of long-lasting insecticidal nets (LLINs) and indoor residual spraying has significantly reduced malaria burden and mortality. However, insecticide resistance, among other factors, is responsible for a recent rebound in malaria transmission in 2015-2016, threatening the progress so far made. As a contribution towards understanding patterns of resistance and its mechanism in the field we characterized a population of Anopheles gambiae (s.l.) from Gounougou, a Guinea savanna of north/central Cameroon. RESULTS Indoor collection conducted in September 2017 identified Anopheles coluzzii and Anopheles arabiensis as the unique Anopheles vector species, with abundances of 83 and 17%, respectively. Analysis of infection with TaqMan assays using heads/thoraces of indoor collected females of An. coluzzii revealed a low Plasmodium falciparum parasite rate of 4.7%. Bioassays conducted with female An. coluzzii revealed extreme resistance, with low mortalities of only 3.75 ± 1.25%, 3.03 ± 1.59% and 1.45 ± 1.45%, respectively, for permethrin, deltamethrin and DDT. In contrast, high susceptibility was obtained with the organophosphates and carbamates, with mortalities in the range of 98-100%. Synergist assays with piperonyl butoxide (PBO) recovered some susceptibility with increased mortality for permethrin to 14.88 ± 8.74%, and for deltamethrin to 32.50 ± 10.51% (~27-fold increase compared to mortalities with deltamethrin alone, χ2 = 29, df = 1, P < 0.0001). These correlated with the results of cone bioassays which revealed complete loss of efficacy of Olyset®Net (0% mortality) and PermaNet®2.0 (0% mortality), and the considerable loss of efficacy of Olyset®Plus (mortality of 2 ± 2%), PermaNet®3.0 side panel (mortality of 2 ± 2%) and PermaNet3.0® roof (mortality of 16 ± 5.1%). Time-course bioassays conducted with deltamethrin established a high intensity of resistance, with LT50 of 309.09 (95% CI 253.07-393.71, Fiducial), and a resistance ratio of 93.09 compared with the fully susceptible Ngoussou laboratory colony. TaqMan genotyping revealed a high frequency of the 1014F allele (65.25%) in the An. coluzzii populations. Sequencing of a fragment of the voltage-gated sodium channel identified a single An. arabiensis female harbouring the 1014S kdr mutation. CONCLUSIONS This finding of high pyrethroid and DDT resistance in An. coluzzii from north-central Cameroon is a major obstacle to malaria control using pyrethroid bednets and indoor residual spraying with DDT.
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Affiliation(s)
- Amen N Fadel
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.,Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Sulaiman S Ibrahim
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK. .,Department of Biochemistry, Bayero University, PMB 3011, Kano, Nigeria.
| | - Magellan Tchouakui
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Ebai Terence
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Murielle J Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.,Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
| | - Micareme Tchoupo
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Samuel Wanji
- Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Charles S Wondji
- LSTM Research Unit, Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.,Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool, L3 5QA, UK
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24
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Tchouakui M, Chiang MC, Ndo C, Kuicheu CK, Amvongo-Adjia N, Wondji MJ, Tchoupo M, Kusimo MO, Riveron JM, Wondji CS. A marker of glutathione S-transferase-mediated resistance to insecticides is associated with higher Plasmodium infection in the African malaria vector Anopheles funestus. Sci Rep 2019; 9:5772. [PMID: 30962458 PMCID: PMC6453935 DOI: 10.1038/s41598-019-42015-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 03/13/2019] [Indexed: 01/02/2023] Open
Abstract
Metabolic resistance to insecticides is threatening malaria control in Africa. However, the extent to which it impacts malaria transmission remains unclear. Here, we investigated the association between a marker of glutathione S-transferase mediated metabolic resistance and Plasmodium infection in field population of Anopheles funestus s.s. in comparison to the A296S-RDL target site mutation. The 119F-GSTe2 resistant allele was present in southern (Obout) (56%) and central (Mibellon) (25%) regions of Cameroon whereas the 296S-RDL resistant allele was detected at 98.5% and 15% respectively. The whole mosquito Plasmodium and sporozoite infection rates were 57% and 14.8% respectively in Obout (n = 508) and 19.7% and 5% in Mibellon (n = 360). No association was found between L119F-GSTe2 genotypes and whole mosquito infection status. However, when analyzing oocyst and sporozoite infection rates separately, the resistant homozygote 119F/F genotype was significantly more associated with Plasmodium infection in Obout than both heterozygote (OR = 2.5; P = 0.012) and homozygote susceptible (L/L119) genotypes (OR = 2.10; P = 0.013). In contrast, homozygote RDL susceptible mosquitoes (A/A296) were associated more frequently with Plasmodium infection than other genotypes (OR = 4; P = 0.03). No additive interaction was found between L119F and A296S. Sequencing of the GSTe2 gene showed no association between the polymorphism of this gene and Plasmodium infection. Glutathione S-transferase metabolic resistance is potentially increasing the vectorial capacity of resistant An. funestus mosquitoes. This could result in a possible exacerbation of malaria transmission in areas of high GSTe2-based metabolic resistance to insecticides.
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Affiliation(s)
- Magellan Tchouakui
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon. .,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon. .,Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon.
| | - Mu-Chun Chiang
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Cyrille Ndo
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon.,University of Douala, P.O. Box 2701, Douala, Cameroon
| | - Carine K Kuicheu
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon.,Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Nathalie Amvongo-Adjia
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon.,Centre for Medical Research, Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O. Box 13033, Yaoundé, Cameroon
| | - Murielle J Wondji
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Micareme Tchoupo
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
| | - Michael O Kusimo
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
| | - Jacob M Riveron
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon.,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon.,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK
| | - Charles S Wondji
- Research Unit LSTM/OCEAC, P.O. BOX 288, Yaoundé, Cameroon. .,Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon. .,Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L35QA, Liverpool, UK.
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Menze BD, Wondji MJ, Tchapga W, Tchoupo M, Riveron JM, Wondji CS. Bionomics and insecticides resistance profiling of malaria vectors at a selected site for experimental hut trials in central Cameroon. Malar J 2018; 17:317. [PMID: 30165863 PMCID: PMC6117958 DOI: 10.1186/s12936-018-2467-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 08/27/2018] [Indexed: 01/31/2023] Open
Abstract
Background Malaria vectors are increasingly developing resistance to insecticides across Africa. The impact of such resistance on the continued effectiveness of insecticide-based interventions remains unclear due to poor characterization of vector populations. This study reports the characterization of malaria vectors at Mibellon, a selected site in Cameroon for experimental hut study, including species composition, Plasmodium infection rate, resistance profiles and mechanisms. Methods Indoor resting blood-fed Anopheles mosquitoes were collected from houses at Mibellon in 2017 and forced to lay eggs to generate F1 adult mosquitoes. Insecticides susceptibility bioassays were performed on the F1 adult mosquitoes following the WHO protocol to assess resistance profile to insecticides. The molecular basis of resistance and Plasmodium infection rate were investigated using TaqMan genotyping. Results Anopheles funestus sensu stricto (s.s.) was predominant in Mibellon (80%) followed by Anopheles gambiae s.s. (20%). High levels of resistance to pyrethroids and organochlorides were observed for both species. Moderate resistance was observed against bendiocarb (carbamate) in both species, but relatively higher in An. gambiae s.s. In contrast, full susceptibility was recorded for the organophosphate malathion. The PBO synergist assays with permethrin and deltamethrin revealed a significant recovery of the susceptibility in Anopheles funestus s.s. population (48.8 to 98.1% mortality and 38.3 to 96.5% mortality, respectively). The DDT/pyrethroid 119F-GSTe2 resistant allele (28.1%) and the dieldrin 296S-RDL resistant (9.7%) were detected in An. funestus s.s. The high pyrethroid/DDT resistance in An. gambiae correlated with the high frequency of 1014F knockdown resistance allele (63.9%). The 1014S-kdr allele was detected at low frequency (1.97%). The Plasmodium infection rate was 20% in An. gambiae, whereas An. funestus exhibited an oocyst rate of 15 and 5% for the sporozoite rate. Conclusion These results highlight the increasing spread of insecticide resistance and the challenges that control programmes face to maintain the continued effectiveness of insecticide-based interventions.
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Affiliation(s)
- Benjamin D Menze
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. .,LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
| | - Murielle J Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - William Tchapga
- LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Micareme Tchoupo
- LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Jacob M Riveron
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Charles S Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. .,LSTM Research Unit at the Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon.
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