[Study on cyfluthrin resistance and its mechanisms of Anopheles sinensis in Nanchang frontierport].

ABSTRACT

OBJECTIVE: To study the cyfluthrin resistance and potential mechanisms of Anopheles sinensis in Nanchang Chang-bei International Airport, Nanchang City, Jiangxi Province. METHODS: The resistance levels of the local An. sinensis were detected by WHO drug resistance bioassay. During the bioassay, the dying mosquitos were classed as sensitive mosquitos, and the survival ones were classed as resistant mosquitos. The P450 monooxygenase activity and glutathione S-transferase activity were detected and compared between the two groups. At the same time, the death time of each sensitive mosquito was recorded, and the correlations between the death time and the P450 monooxygenase activity and glutathione S-transferase activity were analyzed, respectively. RESULTS: The bioassay mortality of the local An. sinensis was 59.5%. The differences of the P450 monooxygenase activities among the resistant mosquitos, sensitive mosquitos and laboratory sensitive mosquitos had statistical significances (F =151.89, P < 0.01), the resistant mosquitos > sensitive mosquitos > laboratory sensitive mosquitos. The differences of glutathione s-transferase activities among the three groups had no statistical significance (F = 0.72, P = 0.49). There existed positive correlation between the mosquito death time and the P450 monooxygenase activity, and the regression equation was y = 79.479 +1.512x with the correlation coefficient of 0.88, while there was no correlation between the mosquito death time and the glutathione S-transferaseactivity. CONCLUSIONS: The An. sinensis in Nanchang Changbei International Airport has been resistant to cyfluthrin, and the promotion of P450 monooxygenase activity maybe one of the reasons for the resistance.