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Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria

Anopheles gambiae, An. coluzzii and An. arabiensis are the three major vectors of malaria in Nigeria. These mosquitoes have developed resistance to different insecticides. Insecticides resistance intensity assay was recently introduced to provide insight into the potential operational significance o...

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Autores principales: Awolola, Taiwo Samson, Adeogun, Adedapo, Olakiigbe, Abiodun K., Oyeniyi, Tolulope, Olukosi, Yetunde Adeola, Okoh, Hilary, Arowolo, Tolulope, Akila, Joel, Oduola, Adedayo, Amajoh, Chioma N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281219/
https://www.ncbi.nlm.nih.gov/pubmed/30517090
http://dx.doi.org/10.1371/journal.pone.0205230
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author Awolola, Taiwo Samson
Adeogun, Adedapo
Olakiigbe, Abiodun K.
Oyeniyi, Tolulope
Olukosi, Yetunde Adeola
Okoh, Hilary
Arowolo, Tolulope
Akila, Joel
Oduola, Adedayo
Amajoh, Chioma N.
author_facet Awolola, Taiwo Samson
Adeogun, Adedapo
Olakiigbe, Abiodun K.
Oyeniyi, Tolulope
Olukosi, Yetunde Adeola
Okoh, Hilary
Arowolo, Tolulope
Akila, Joel
Oduola, Adedayo
Amajoh, Chioma N.
author_sort Awolola, Taiwo Samson
collection PubMed
description Anopheles gambiae, An. coluzzii and An. arabiensis are the three major vectors of malaria in Nigeria. These mosquitoes have developed resistance to different insecticides. Insecticides resistance intensity assay was recently introduced to provide insight into the potential operational significance of insecticide resistance. Here, we present data on pyrethroids resistance intensity and resistance mechanisms from six vector surveillance sites (Lagos, Ogun, Edo, Anambra, Kwara and Niger) in Nigeria. Adult Anopheles reared from larval collections were tested using WHO insecticides susceptibility protocol with 1x concentration of permethrin and deltamethrin followed with intensity assays with 5x and 10x concentrations of both insecticides. Synergistic and biochemical assays were carried out and underlying resistance mechanisms determined following standard protocols. Anopheles gambiae constituted >50% samples tested in five sites. Permethrin and deltamethrin resistance was observed at all the sites. The Kdt50 varied from 15 minutes (CI = 13.6–17.2) in deltamethrin to 42.1 minutes (CI = 39.4–44.1) in permethrin. For both insecticides, Kdt95 was >30 minutes with 25% to 87% post exposure mortality at the different sites. The West Africa knock down resistance (kdr-w) mechanism was found at each site. Resistant An. gambiae from Lagos, Ogun and Niger synergized prior to permethrin or deltamethrin exposure showed significant mortality (89–100%) compared to unsynergized mosquitoes (Lagos, p = 0.031; Ogun, p = 0.025; Niger, p = 0.018). Biochemical analyses revealed significant increased levels of P450 enzymes in resistant Anopheles gambiae from Lagos (p = 0.038); Ogun (p = 0.042) and Niger (p = 0.028) in addition to GST in Lagos (p = 0.028) and Ogun (p = 0.033). Overall, the results revealed high pyrethroid resistance associated with increased activities of metabolic enzymes (P450 + GST) in An. gambiae and An. coluzzii from Lagos and Ogun. The presence of kdr + P450 conferred moderate resistance whereas low resistance was the case where kdr was the sole resistance mechanism. Findings thus suggests that elevated levels of cytochrome P450 enzymes together with GST were responsible for high or severe pyrethroid resistance.
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spelling pubmed-62812192018-12-20 Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria Awolola, Taiwo Samson Adeogun, Adedapo Olakiigbe, Abiodun K. Oyeniyi, Tolulope Olukosi, Yetunde Adeola Okoh, Hilary Arowolo, Tolulope Akila, Joel Oduola, Adedayo Amajoh, Chioma N. PLoS One Research Article Anopheles gambiae, An. coluzzii and An. arabiensis are the three major vectors of malaria in Nigeria. These mosquitoes have developed resistance to different insecticides. Insecticides resistance intensity assay was recently introduced to provide insight into the potential operational significance of insecticide resistance. Here, we present data on pyrethroids resistance intensity and resistance mechanisms from six vector surveillance sites (Lagos, Ogun, Edo, Anambra, Kwara and Niger) in Nigeria. Adult Anopheles reared from larval collections were tested using WHO insecticides susceptibility protocol with 1x concentration of permethrin and deltamethrin followed with intensity assays with 5x and 10x concentrations of both insecticides. Synergistic and biochemical assays were carried out and underlying resistance mechanisms determined following standard protocols. Anopheles gambiae constituted >50% samples tested in five sites. Permethrin and deltamethrin resistance was observed at all the sites. The Kdt50 varied from 15 minutes (CI = 13.6–17.2) in deltamethrin to 42.1 minutes (CI = 39.4–44.1) in permethrin. For both insecticides, Kdt95 was >30 minutes with 25% to 87% post exposure mortality at the different sites. The West Africa knock down resistance (kdr-w) mechanism was found at each site. Resistant An. gambiae from Lagos, Ogun and Niger synergized prior to permethrin or deltamethrin exposure showed significant mortality (89–100%) compared to unsynergized mosquitoes (Lagos, p = 0.031; Ogun, p = 0.025; Niger, p = 0.018). Biochemical analyses revealed significant increased levels of P450 enzymes in resistant Anopheles gambiae from Lagos (p = 0.038); Ogun (p = 0.042) and Niger (p = 0.028) in addition to GST in Lagos (p = 0.028) and Ogun (p = 0.033). Overall, the results revealed high pyrethroid resistance associated with increased activities of metabolic enzymes (P450 + GST) in An. gambiae and An. coluzzii from Lagos and Ogun. The presence of kdr + P450 conferred moderate resistance whereas low resistance was the case where kdr was the sole resistance mechanism. Findings thus suggests that elevated levels of cytochrome P450 enzymes together with GST were responsible for high or severe pyrethroid resistance. Public Library of Science 2018-12-05 /pmc/articles/PMC6281219/ /pubmed/30517090 http://dx.doi.org/10.1371/journal.pone.0205230 Text en © 2018 Awolola et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Awolola, Taiwo Samson
Adeogun, Adedapo
Olakiigbe, Abiodun K.
Oyeniyi, Tolulope
Olukosi, Yetunde Adeola
Okoh, Hilary
Arowolo, Tolulope
Akila, Joel
Oduola, Adedayo
Amajoh, Chioma N.
Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title_full Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title_fullStr Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title_full_unstemmed Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title_short Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria
title_sort pyrethroids resistance intensity and resistance mechanisms in anopheles gambiae from malaria vector surveillance sites in nigeria
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281219/
https://www.ncbi.nlm.nih.gov/pubmed/30517090
http://dx.doi.org/10.1371/journal.pone.0205230
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