Knockdown resistance mutations (kdr) and insecticide susceptibility to DDT and pyrethroids in Anopheles gambiae from Equatorial Guinea
Knockdown resistance mutations (kdr) and insecticide susceptibility to DDT and pyrethroids in Anopheles gambiae from Equatorial Guinea
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DOI：
10.1111/j.1365-3156.2008.02010.x
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Benito, A.
中科院分区：
文献类型：
--
作者：
Moreno, M.;Vicente, J. L.;Benito, A.
为了确定疟疾媒介冈比亚按蚊s.s.从大陆赤道几内亚;和KDR基因型与敏感性滴滴涕和拟除虫菊酯类杀虫剂在这个vector.METHODS雌蚊收集在两个村庄，Miyobo和Ngonamanga，大陆赤道几内亚。按照世卫组织程序进行了抗生素敏感性试验。应用PCR技术对冈比亚按蚊复合体标本进行种和分子形态鉴定。通过等位基因特异性PCR和直接测序对部分样本进行kdr基因分型。在Ngonamanga中发现了gambiae，而在Miyobo中仅鉴定了S型。在两个村庄的S型样本中均检测到两种kdr突变，其中kdr-e（Leu-1014-Ser）等位基因的频率较高（Miyobo：16%; Ngonamanga：40%）。在3%的M型中也检测到kdr-w（Leu-1014-Phe）突变。所有接受拟除虫菊酯检测的个体均易感。滴滴涕的死亡率为86%。DDT抗性个体kdr基因频率（即kdr-e + kdr-w）为22%，敏感个体kdr基因频率为6%。冈比亚的报告强调了在赤道几内亚对杀虫剂抗药性进行有效监测的重要性。
OBJECTIVES To determine the frequency of knockdown resistance (kdr) mutations in the malaria vector Anopheles gambiae s.s. from continental Equatorial Guinea; and to relate kdr genotypes with susceptibility to DDT and pyrethroid insecticides in this vector.METHODS Female mosquitoes were collected in two villages, Miyobo and Ngonamanga, of mainland Equatorial Guinea. Insecticide susceptibility tests were performed following WHO procedures. Anopheles gambiae complex specimens were identified to species and molecular form by PCR. Genotyping of the kdr locus was performed by allele-specific PCR and direct sequencing in a subset of samples.RESULTS Both M and S molecular forms of A. gambiae were found in Ngonamanga whereas only the S-form was identified in Miyobo. The two kdr mutations were detected in S-form samples of both villages, with a higher frequency of the kdr-e (Leu-1014-Ser) allele (Miyobo: 16%; Ngonamanga: 40%). The kdr-w (Leu-1014-Phe) mutation was also detected in 3% of the M-form. All individuals tested for pyrethroids were susceptible. A mortality rate of 86% was obtained for DDT. An overall kdr allele frequency (i.e. kdr-e + kdr-w) of 22% was detected in DDT resistant individuals, whereas susceptible individuals had a kdr frequency of 6%.CONCLUSION The co-occurrence of both kdr mutations and reduced susceptibility to DDT found in A. gambiae highlights the importance of implementing efficient surveillance of insecticide resistance in Equatorial Guinea.