五株白纹伊蚊对溴氰菊酯抗性生物测定和生化检测的研究

目的检测采自野外株和实验室驯化株白纹伊蚊对溴氰菊酯的抗性水平,探讨实验室抗性株(R-lab)的抗性机理。方法以采自深圳、广州龙洞和东莞庄的三株白纹伊蚊(SZ,LD和DW)和两株实验室驯化白纹伊蚊(S-lab和R-lab)为研究对象,采用WHO推荐的幼虫浸渍法分别测定它们的抗药性水平,并采用PBO增效实验和生化检测方法测定R-lab株代谢酶活性。结果与S-lab株相比,R-lab株抗性倍数最高(RR50:480),而采自野外的三株抗性倍数较低(LD:6.6;DW:8.5;SZ:2.0)。对R-lab株活体增效实验和离体解毒酶实验结果表明PBO增效作用显著,增效倍数为120倍,GST酶活性上升1.29倍,EST酶活性没有改变。结论R-lab株和野外的三个种群对溴氰菊酯均有一定的抗性水平,以R-lab株抗性水平最高;代谢抗性是R-lab株抗药性形成的主要机理之一,其中细胞色素P450单加氧酶活性升高占据主导地位。

Bioassay and biochemical assay of the resistance to deltametherin in five strains of Aedes albopictus

To determine the resistance to deltametherin of 3 strains of Aedes albopictus from field surveys and 2 strains from laboratories, and to explore the possible mechanism of resistance to deltamethrin, the field stains SZ, DW and LD strains and the laboratory strains S-lab and R-lab were used in the present study, and the resistance levels were measured with the larva immersed method recommended by WHO in order to elucidate the possible mechanism of resistance of R-lab strain with the PBO synergism and biochemical assays. It was found that the RR50 of these 3 field strains and the laboratory strain R-lab were 6.6, 8.5, 2.0 and 480 respectively, and the synergism radio of PBO of R-lab strain was 120. The GST activity was 1.29, while the EST acdvity showed no obvious variation. It is evident that the R-lab is a highly resistant strain to deltamethrin and the resistance levels of these 3 field strains are rather low. It is also shown that resistance to metabolic detoxification would be the major mechanism for resistance in R-lab strain, and the increased activity of cytochrome P450 mono-oxygenase may play a major role.