中华按蚊溴氰菊酯处理后存活与死亡群体击倒抗性突变型差异比较

Comparison of knockdown resistance mutations between survival and death populations of Anopheles sinensis after deltamethrin resistance test

目的探讨溴氰菊酯抗性中华按蚊群体不同抗性突变类型对蚊虫抗性的影响。方法对2011及2012年合肥市6个调查点中华按蚊采用WHO接触筒法进行溴氰菊酯敏感性测试,留存抗性测试后存活与死亡中华按蚊标本,两种群体各随机选取80只标本,实验室提取基因组进行钠离子通道蛋白扩增并双向测序,两群体间突变类型比较采用SPSS软件进行χ2检验。结果测序发现两种群体均存在2种突变类型,即由TTG向TTT及TGT突变。对测序图进行比对发现存在4种突变组合,即TTG(T)杂合、TTT纯合、TG(T)G(T)杂合和TG(T)T杂合。对两种群体TTG、TTT及TGT 3种单倍型构成进行比较,χ2=17.571,P<0.01,存活群体TGT单倍型构成(36.9%)高于死亡群体(19.4%)。结论 TGT抗性突变类型对溴氰菊酯抗性的效应高于TTT突变。

Objective To investigate the effect of knockdown resistance mutations on the dehamethrin resistance of Anopheles sinensis. Methods The dehamethrin resistance of An. sinensis was determined by WHO cones test at six investigation sites in Hefei, China, from 2011 to 2012. Eighty An. sinensis specimens were randomly selected from each of the survival and death populations after the resistance test. DNA was extracted as templates for PCR amplification, and the IIS5-S6 transmembrane segments of voltage- gated sodium channel （VGSC） gene were cloned and sequenced. Chi- square test was used to compare mutation types between the two populations with SPSS software. Results Sequence analysis revealed two types of mutations （TTG to TIT and TTG to TGT） in both groups, with four combinations, i.e., heterozygous mutations TTG（T）, TG（T）G（T）, and TG（T） T and homozygous mutation （TTT）. TGT mutation accounted for 36.9% of the survival population, higher than that of the death population （19.4%） （χ^2= 17.571, P〈0.01）, according to the comparison of mutation types （TTG, TTT, and TGT） between the two populatons. Conclusion TGT mutation is more associated with deltamethrin resistance than TTT mutation.