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Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum

BACKGROUND: The control of most vectors of malaria is threatened by the spread of insecticide resistance. One factor that has been hitherto largely overlooked is the potential effects of insecticide resistance on the ability of mosquitoes to transmit malaria: are insecticide-resistant mosquitoes as...

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Autores principales: Vézilier, Julien, Nicot, Antoine, Gandon, Sylvain, Rivero, Ana
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3313086/
https://www.ncbi.nlm.nih.gov/pubmed/21194433
http://dx.doi.org/10.1186/1475-2875-9-379
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author Vézilier, Julien
Nicot, Antoine
Gandon, Sylvain
Rivero, Ana
author_facet Vézilier, Julien
Nicot, Antoine
Gandon, Sylvain
Rivero, Ana
author_sort Vézilier, Julien
collection PubMed
description BACKGROUND: The control of most vectors of malaria is threatened by the spread of insecticide resistance. One factor that has been hitherto largely overlooked is the potential effects of insecticide resistance on the ability of mosquitoes to transmit malaria: are insecticide-resistant mosquitoes as good vectors of Plasmodium as susceptible ones? The drastic physiological changes that accompany the evolution of insecticide resistance may indeed alter the ability of vectors to transmit diseases, a possibility that, if confirmed, could have major epidemiological consequences. METHODS: Using a novel experimental system consisting of the avian malaria parasite (Plasmodium relictum) and its natural vector (the mosquito Culex pipiens), two of the most common mechanisms of insecticide resistance (esterase overproduction and acetylcholinesterase modification) were investigated for their effect on mosquito infection rate and parasite burden. For this purpose two types of experiments were carried out using (i) insecticide-resistant and susceptible laboratory isogenic lines of Cx. pipiens and (ii) wild Cx. pipiens collected from a population where insecticide resistant and susceptible mosquitoes coexist in sympatry. RESULTS: The isogenic line and wild-caught mosquito experiments were highly consistent in showing no effect of either esterase overproduction or of acetylcholinesterase modification on either the infection rate or on the oocyst burden of mosquitoes. The only determinant of these traits was blood meal size, which was similar across the different insecticide resistant categories in both experiments. CONCLUSIONS: Insecticide resistance was found to have no effect on Plasmodium development within the mosquito. This is the first time this question has been addressed using a natural mosquito-Plasmodium combination, while taking care to standardize the genetic background against which the insecticide resistance genes operate. Infection rate and oocyst burden are but two of the factors that determine the vectorial capacity of mosquitoes. Other key determinants of parasite transmission, such as mosquito longevity and behaviour, or the parasite's incubation time, need to be investigated before concluding on whether insecticide resistance influences the ability of mosquitoes to transmit malaria.
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spelling pubmed-33130862012-03-28 Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum Vézilier, Julien Nicot, Antoine Gandon, Sylvain Rivero, Ana Malar J Research BACKGROUND: The control of most vectors of malaria is threatened by the spread of insecticide resistance. One factor that has been hitherto largely overlooked is the potential effects of insecticide resistance on the ability of mosquitoes to transmit malaria: are insecticide-resistant mosquitoes as good vectors of Plasmodium as susceptible ones? The drastic physiological changes that accompany the evolution of insecticide resistance may indeed alter the ability of vectors to transmit diseases, a possibility that, if confirmed, could have major epidemiological consequences. METHODS: Using a novel experimental system consisting of the avian malaria parasite (Plasmodium relictum) and its natural vector (the mosquito Culex pipiens), two of the most common mechanisms of insecticide resistance (esterase overproduction and acetylcholinesterase modification) were investigated for their effect on mosquito infection rate and parasite burden. For this purpose two types of experiments were carried out using (i) insecticide-resistant and susceptible laboratory isogenic lines of Cx. pipiens and (ii) wild Cx. pipiens collected from a population where insecticide resistant and susceptible mosquitoes coexist in sympatry. RESULTS: The isogenic line and wild-caught mosquito experiments were highly consistent in showing no effect of either esterase overproduction or of acetylcholinesterase modification on either the infection rate or on the oocyst burden of mosquitoes. The only determinant of these traits was blood meal size, which was similar across the different insecticide resistant categories in both experiments. CONCLUSIONS: Insecticide resistance was found to have no effect on Plasmodium development within the mosquito. This is the first time this question has been addressed using a natural mosquito-Plasmodium combination, while taking care to standardize the genetic background against which the insecticide resistance genes operate. Infection rate and oocyst burden are but two of the factors that determine the vectorial capacity of mosquitoes. Other key determinants of parasite transmission, such as mosquito longevity and behaviour, or the parasite's incubation time, need to be investigated before concluding on whether insecticide resistance influences the ability of mosquitoes to transmit malaria. BioMed Central 2010-12-31 /pmc/articles/PMC3313086/ /pubmed/21194433 http://dx.doi.org/10.1186/1475-2875-9-379 Text en Copyright ©2010 Vézilier et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (<url>http://creativecommons.org/licenses/by/2.0</url>), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Vézilier, Julien
Nicot, Antoine
Gandon, Sylvain
Rivero, Ana
Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title_full Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title_fullStr Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title_full_unstemmed Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title_short Insecticide resistance and malaria transmission: infection rate and oocyst burden in Culex pipiens mosquitoes infected with Plasmodium relictum
title_sort insecticide resistance and malaria transmission: infection rate and oocyst burden in culex pipiens mosquitoes infected with plasmodium relictum
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3313086/
https://www.ncbi.nlm.nih.gov/pubmed/21194433
http://dx.doi.org/10.1186/1475-2875-9-379
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