塞内加尔东南部野外采获的冈比亚按蚊（按蚊复合体）成蚊中存在多个杀虫剂抗性靶标位点。

Multiple insecticide resistance target sites in adult field strains of An. gambiae (s.l.) from southeastern Senegal.

机构信息

Laboratoire d'Écologie Vectorielle et Parasitaire, Université Cheikh Anta Diop de Dakar, Dakar, Senegal.

Institut Pasteur de Dakar, Dakar, Senegal.

出版信息

Parasit Vectors. 2020 Nov 11;13(1):567. doi: 10.1186/s13071-020-04437-z.

DOI:10.1186/s13071-020-04437-z

PMID:33176872

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7661151/

Abstract

BACKGROUND

High coverage of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the cornerstones of vector control strategy in Senegal where insecticide resistance by the target vectors species is a great of concern. This study explores insecticide susceptibility profile and target-site mutations mechanisms within the Anopheles gambiae complex in southeastern Senegal.

METHODS

Larvae of Anopheles spp. were collected in two sites from southeastern Senegal Kedougou and Wassadou/Badi in October and November 2014, and reared until adult emergence. Wild F adult mosquitoes were morphologically identified to species. Susceptibility of 3-5-day-old An. gambiae (s.l.) samples to 11 insecticides belonging to the four insecticide classes was assessed using the WHO insecticide susceptibility bioassays. Tested samples were identified using molecular techniques and insecticide resistance target-site mutations (kdr, ace-1 and rdl) were determined.

RESULTS

A total of 3742 An. gambiae (s.l.) were exposed to insecticides (2439 from Kedougou and 1303 from Wassadou-Badi). Tests with pyrethroid insecticides and DDT showed high level of resistance in both Kedougou and Wassadou/Badi. Resistance to pirimiphos-methyl and malathion was not detected while resistance to bendoicarb and fenitrothion was confirmed in Kedougou. Of the 745 specimens of An. gambiae (s.l.) genotyped, An. gambiae (s.s.) (71.6%) was the predominant species, followed by An. arabiensis (21.7%), An. coluzzii (6.3%) and hybrids (An. gambiae (s.s.)/An. coluzzii; 0.4%). All target site mutations investigated (Vgsc-1014F, Vgsc-1014S, Ace-1 and Rdl) were found at different frequencies in the species of the Anopheles gambiae complex. Vgsc-1014F mutation was more frequent in An. gambiae (s.s.) and An. coluzzii than An. arabiensis. Vgsc-1014S was present in An. gambiae (s.l.) populations in Wassadou but not in Kedougou. Ace-1 and rdl mutations were more frequent in An. gambiae (s.s.) in comparison to An. arabiensis and An. coluzzii.

CONCLUSIONS

Resistance to all the four insecticide classes tested was detected in southeastern Senegal as well as all target site mutations investigated were found. Data will be used by the national Malaria Control Programme.

摘要

背景

在塞内加尔，长效杀虫蚊帐（LLINs）和室内滞留喷洒（IRS）的高覆盖率是病媒控制策略的基石，而目标病媒物种的抗药性是一个重大问题。本研究探讨了塞内加尔东南部冈比亚疟蚊复合体中的杀虫剂敏感性概况和靶标位点突变机制。

方法

2014 年 10 月和 11 月，在塞内加尔东南部的凯杜古和瓦萨杜/巴迪采集了两种地点的按蚊属幼虫，并饲养至成虫出现。野生 F 代成蚊通过形态学鉴定到种。使用世界卫生组织的杀虫剂敏感性生物测定法，对 3-5 龄期的冈比亚按蚊（s.l.）样本进行了对 11 种属于 4 种杀虫剂类别的杀虫剂的敏感性测试。使用分子技术对测试样本进行鉴定，并确定了杀虫剂抗性靶标位点突变（kdr、ace-1 和 rdl）。

结果

共对 3742 只冈比亚按蚊（s.l.）进行了杀虫剂暴露测试（凯杜古 2439 只，瓦萨杜/巴迪 1303 只）。在凯杜古和瓦萨杜/巴迪，测试的拟除虫菊酯类杀虫剂和滴滴涕均显示出高水平的抗性。未发现对吡虫啉和马拉硫磷的抗性，但在凯杜古证实对苯氧威和三唑磷有抗性。在 745 只冈比亚按蚊（s.l.）的基因型中，冈比亚按蚊（s.s.）（71.6%）是主要物种，其次是阿拉伯按蚊（21.7%）、冈比亚按蚊（6.3%）和杂交种（冈比亚按蚊（s.s.）/冈比亚按蚊（coluzzii；0.4%）。在所研究的所有靶标位点突变（Vgsc-1014F、Vgsc-1014S、Ace-1 和 Rdl）在冈比亚按蚊复合体的不同物种中以不同的频率出现。Vgsc-1014F 突变在冈比亚按蚊（s.s.）和冈比亚按蚊（coluzzii）中比在阿拉伯按蚊中更为频繁。Vgsc-1014S 存在于瓦萨杜的按蚊（s.l.）种群中，但在凯杜古没有发现。与阿拉伯按蚊和冈比亚按蚊（coluzzii）相比，Ace-1 和 rdl 突变在冈比亚按蚊（s.s.）中更为频繁。