云南及河南省部分地区中华按蚊对溴氰菊酯抗性及kdr突变频率调查

Investigation on the resistance of Anopheles sinensis to deltamethrin and its association with the kdr genotypes in Yunnan province and parts of Henan province

目的了解云南及河南省部分地区中华按蚊对溴氰菊酯杀虫剂的抗药性状况及该抗性与击倒抗性基因型的关联性。方法2010年7-8月采集云南省勐腊和元阳县,河南省桐柏、淮滨县以及永城市中华按蚊样本,F1代成蚊用接触筒内成蚊药膜滤纸接触法,按照WHO区分剂量,调查5个地区中华按蚊对溴氰菊酯的抗药性状况,并以PCR产物直接测序法抽取部分样本对kdr相关钠离子通道1014位点的基因型进行检测。结果5个地区中华按蚊溴氰菊酯区分剂量死亡率均<98%,其中淮滨县、永城市、桐柏和元阳县中华按蚊的死亡率均<80%,为抗性群体;勐腊县中华按蚊为初步抗性群体。PCR产物测序结果显示,河南省淮滨县、永城市和桐柏县中华按蚊样本中均发现kdr位点突变,云南省元阳和勐腊县中华按蚊样本中未发现kdr位点突变。结论河南省永城市和桐柏县的溴氰菊酯抗性与kdr位点突变相关;淮滨县中华按蚊kdr突变率高,但未发现其与溴氰菊酯抗性的关联。

Objective To investigate resistance of Anopheles sinensis to deltamethrin and its association with the kdr gene mutation in Yunnan province and parts of Henan province.Methods The An.sinensis samples were collected from Yuanyang and Mengla of Yunnan province and Tongbai,Huaibin and Yongcheng of Henan province in July and August of 2010.The standard WHO deltamethrin resistance bioassay was used to evaluate the resistance of the insects to deltamethrin by the knockdown rate and the mortality of them,and the genotype at the site 1014 Leu-Phe mutation in the kdr associated sodium channel gene was detected by polymerase chain reaction and sequencing.Results The results showed that the mortalities of An.sinensis in all the 5 regions were all lower than 98%,with death rate of less than 80% in Huaibin,Yongcheng,Tongbai and Yuanyang,where the populations were resistant.Also,elementary resistance was seen in Mengla county where the mortality was between 80%-97%.The kdr mutation was found through sequence analysis of the PCR products in the Huaibin,Yongcheng and Tongbai populations with no kdr mutation observed in the Mengla and Yuanyang populations.Conclusion There is a correlation between kdr mutation and the deltamethrin resistant phenotype in the Yongcheng and Tongbai populations,but no such a correlation has been found in the Huaibin,Mengla and Yuanyang populations.