多哥冈比亚按蚊靶标抗性kdr、ace-1基因突变研究

Investigation of target resistance kdr, ace-1 mutations in Anopheles gambiae s.l. in Togo

目的 调查多哥冈比亚按蚊(Anopheles gambiae s.l.)中kdr和ace-1的等位基因突变,为该地区蚊媒传染病防制提供科学依据。方法 蚊虫样本采集自多哥2个疟疾高发地区东莫诺(Est-mono)和阿涅(Anié)的6个村庄。所有蚊虫均用于蚊种鉴定以及kdr和ace-1基因分型。结果 An. coluzzii和An. gambiae是在6个采集地点发现的2个冈比亚按蚊复合组中的近缘物种,其中An. gambiae占主导地位,占比约为96.53%。在所有检测到的蚊虫样品中,冈比亚按蚊复合组在kdr 1014位点具有高频率的突变,其中An. gambiae在奥古库利代(Ogou koulidé)、巴纳(Bana)、阿福莱(Afolé)地区突变频率达到100.0%,凯普西(Kepssi)、伊格博梅吉(Igbomedji)的突变频率为97.5%,科洛科佩(Kolocopé)地区突变频率为91.1%,1014F的等位基因频率为85.5%~100.0%,3个地区的An. coluzzii 1014位点的突变频率均为100.0%,1014F的等位基因频率为90.0%~100.0%,突变纯合度较高。An. gambiae在kdr 1575的突变频率为6.6%~24.3%,1575Y的等位基因频率为3.2%~12.2%,所有检测到的突变类型均为杂合突变,An. coluzzii的1575位点未检测到突变。冈比亚按蚊复合组在ace-1基因的119位点也检测到了突变,其中An. gambiae的突变频率为8.8%~15.0%,119S等位基因频率为4.4%~7.5%,An. coluzzii的突变频率为0~20.0%,119S等位基因频率为0~10.0%,所有检测到的119S突变均为杂合突变。结论 由于本研究中检测到的多哥冈比亚按蚊kdr突变频率很高,疟疾蚊媒可能对拟除虫菊酯类杀虫剂已产生高度抗性,同时可能对有机磷或氨基甲酸酯类杀虫剂也产生一定的抗性。提示当地相关病媒管理部门在今后的疟疾病媒控制及耐药性管理规划中应着重考虑杀虫剂耐药问题,并定期进行监测。

Objective To investigate the allelic mutations of kdr and ace-1 in Anopheles gambiae s.l.,providing a scientific basis for mosquito-borne disease prevention and control in the region.Methods Mosquitoes were collected from six villages in two malaria-prone areas,Est-mono(Ogou koulidé,Kepssi,Igbomedji)and Anié(Kolocopé,Bana,Afolé).All mosquitoes were used for DNA extraction,species identification,and genotyping of kdr and ace-1.Results An.coluzzii and An.gambiae,two closely related species within the An.gambiae complex,were identified across six collection sites,with An.gambiae being predominant,constituting approximately 96.53%of the samples.Among all mosquito samples detected,high-frequency mutations were observed at the kdr 1014 locus in the An.gambiae complex,with mutation frequencies reaching 100.0%in Ogou koulidé,Bana,and Afolé,97.5%in Kepssi and Igbomedji,and 91.1%in Kolocopédistrict.The allelic frequency of 1014F ranged from 85.5%to 100%.Mutation frequency of An.coluzzii 1014 locus in all three regions was 100%,with an allelic frequency of 1014F ranging from 90%to 100%,indicating a high rate of homozygosity.The kdr 1575 mutation frequency in An.gambiae ranged from 6.6%to 24.3%,with the allelic frequency of 1575Y ranging from 3.2%to 12.2%,all detected mutations were heterozygous,and no mutations were detected at the 1575 locus in An.coluzzii.Mutations at the ace-1 G119 locus were also observed in the An.gambiae complex,with mutation frequencies in An.gambiae ranging from 8.8%to 15%and the allelic frequency of 119S from 4.4%to 7.5%.In An.coluzzii,mutation frequencies ranged from 0 to 20.0%,with an allelic frequency of 119S from 0 to 10%,and all detected 119S mutations were heterozygous.Conclusions The high frequencies of the Anopheles gambiae kdr mutation observed suggest that malaria mosquito vectors in Togo may have developed a high level of resistance to pyrethroid insecticides and possibly a moderate resistance to organophosphorus or carbamate insecticides.This indicates that local vector management authorities should prioritize insecticide resistance issues in future malaria vector control and resistance management planning,and conduct regular monitoring.