中华按蚊对菊酯类杀虫剂的抗性及kdr突变

Pyrethroid resistance and kdr mutations in Anopheles sinensis

目的了解江苏省洪泽湖地区疟疾媒介中华按蚊对菊酯类杀虫剂的抗性状况及钠离子通道部分位点突变情况。方法 2012-2013年8-9月,沿洪泽湖周边采集淮安、洪泽、泗洪、盱眙、泗阳等地区中华按蚊成蚊样本,圆球法检测击倒中时间(KT50)。多重PCR法检测钠离子通道1014位点kdr基因突变情况。结果 5个地区采集的按蚊均为中华按蚊,中华按蚊成蚊对氯菊酯、高效氯氰菊酯、溴氰菊酯3种杀虫剂的平均KT50分别为16.92、16.53、22.98 min,抗性倍数为4.61、5.45和4.60,均为抗性种群。部分kdr基因发生突变,存在L1014C和L1014F两种突变类型,7种基因型(TTG/TTG,TTG/TTT,TTG/TTC,TTG/TTG,TTT/TTT,TTT/TTC,TGT/TGT)主要突变类型为TTT(或TTC),突变频率为72%~87%,其次为TGT突变12%~21%,敏感的TTG较少。结论该地区中华按蚊对3种菊酯类杀虫剂产生一定的抗性,钠离子通道kdr基因L1014位点出现高频率的突变,突变类型主要为TTT和TGT,提示该地区中华按蚊成蚊防治需根据抗性监测结果加强抗性治理。

Objective To understand the pyrethroid insecticides resistance level and mutations in the para type sodium channel gene that confers kdr in Anopheles sinensis from malaria endemic areas along the Hongze Lake in Jiangsu Province. Methods An. sinensis adult mosquitoes were collected in primarily milk cowsheds and pigsties of countryside Jiangsu Province from August to September in 2012- 2013. The insecticide resistance bioassays were performed on adult mosquitoes by using the pesticide impregnated mesh Wire-Balls assay. Multiple-PCR method was used to distinguish the mosquito species and genotyping the kdr mutations. Results All the mosquitoes collected in the five counties were An. sinensis. The average KT50 s of the three pyrethroid insecticides were 16. 92 min to permethrin,16. 53 min to beta cypermethrin and 22. 98 min to deltamethrin in the five population respectively. The R / S values were 4. 61,5. 45,4. 60 which suggested that the five populations were resistant to the insecticides. There were two kinds of substitutions( L1014 C and L1014f) and seven genotypes( TTG / TTG,TTG / TTT,TTG / TTC,TTG / TTG,TTT / TTT,TTT / TTC,TGT / TGT) in the para sodium channel based on the multiple-PCR method. The mutation frequencies of 1014 F and 1014 C were 72%- 87% and 12%- 21% respectively. Conclusion The mosquito population from the five regions around the Hongze Lake all develope resistance to the tested insecticides. High genotyping frequencies of kdr mutations exist in the five populations. Resistance management should be introduced in these regions.