南宁市2022年白纹伊蚊击倒抗性基因型分布研究

Distribution of knockdown resistance genotypes in Aedes albopictus in Nanning,Guangxi Zhuang Autonomous Region,China,2022

目的检测广西壮族自治区南宁市登革热媒介白纹伊蚊现场种群的击倒抗性基因型及其分布特点,以了解其抗药性水平,为科学防控白纹伊蚊提供依据。方法2022年在南宁市采用勺捕法采集伊蚊幼蚊,送实验室饲养至成虫,经形态学方法鉴定后,将白纹伊蚊用75%乙醇溶液浸泡,于-20℃保存备用。采用磁珠法试剂盒提取单只成蚊DNA,PCR扩增电压门控钠离子通道(VGSC)基因部分片段,测序结果在美国国立生物技术信息中心进行BLAST比对,对确认为白纹伊蚊VGSC基因的序列使用DNAStar 7.1分析其VGSC基因单位点及多位点联合突变情况。结果共检测175只白纹伊蚊,获得350条基因序列,长度约为400 bp,VGSC基因1532位点未发现突变,1016和1534位点均存在突变。1016位点有2种等位基因,分别为野生型1016V(148,78.28%)和突变型1016G(49,21.72%);3种基因型分别为野生型纯合子1016V/V(126,72.00%)、突变型纯合子1016G/G(27,15.43%)和野生/突变型杂合子1016V/G(22,12.57%)。1532位点有1种等位基因,即野生型1532I(175,100%);基因型均为野生型纯合子1532I/I。1534位点有3种等位基因,分别为野生型1534F(51,16.86%)、突变型1534S(116,36.29%)和突变型1534C(135,46.85%);6种基因型分别为野生型纯合子1534F/F(8,4.57%)、野生/突变型杂合子1534F/S(21,12.00%)、野生/突变型杂合子1534F/C(22,12.57%)、突变型杂合子1534S/C(64,36.57%)、突变型纯合子1534S/S(21,12.00%)和突变型纯合子1534C/C(39,22.29%)。结论南宁市VGSC基因突变率较高,应密切关注白纹伊蚊抗药性水平,科学、规范、高效地指导卫生杀虫剂的使用。

Objective To investigate knockdown resistance(kdr)genotypes of Aedes albopictus which is the major vector of dengue in Nanning,so as to understand their insecticide resistance levels and provide evidence for scientific control of Ae.albopictus.Methods Ae.albopictus larvae were collected using the dip method in Nanning and raised to adults in the laboratory.After morphological identification,Ae.albopictus mosquitoes were soaked in 75%ethanol and stored at-20℃.DNA was extracted from individual mosquitoes using the magnetic bead-based method.The partial fragments of the voltage-gated sodium channel(VGSC)gene were amplified by PCR and sequenced for alignment with the Basic Local Alignment Search Tool on the platform of National Center for Biotechnology Information.DNAStar 7.1 was used to analyze single-site and multiple-site mutations in the confirmed VGSC gene of Ae.albopictus mosquitoes.Results A total of 175 Ae.albopictus mosquitoes were examined in 2022,obtaining 350 sequences(about 400 bp in length).Mutations were detected at the 1016 and 1534 loci but not at the 1532 locus of the VGSC gene.At the 1016 locus,there were two alleles(wild-type V[148,78.28%]and mutant G[49,21.72%])and three genotypes(wild-type homozygote V/V[126,72.00%],mutant homozygote G/G[27,15.43%],and wild-type/mutant heterozygote V/G[22,12.57%]).At the 1532 locus,there was one allele(wild-type I[175,100%])and one genotype(wild-type homozygote I/I[175,100%]).At the 1534 locus,there were three alleles(wild-type F[51,16.86%],mutant S[116,36.29%],and mutant C[135,46.85%])and six genotypes(wild-type homozygote F/F[8,4.57%],wild/mutant heterozygotes F/S[21,12.00%]and F/C[22,12.57%],mutant heterozygote S/C[64,36.57%],and mutant homozygotes S/S[21,12.00%]and C/C[39,22.29%]).Conclusion VGSC gene mutations are frequent in Ae.albopictus in Nanning.Attention should be paid to the insecticide resistance levels of Ae.albopictus for scientific,standardized,and efficient use of insecticides.