Martins Ademir Jesus, Lins Rachel Mazzei Moura de Andrade, Linss Jutta Gerlinde Birgitt, Peixoto Alexandre Afranio, Valle Denise
Laboratório de Fisiologia e Controle de Artrópodes Vetores, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro - RJ, Brazil.
Am J Trop Med Hyg. 2009 Jul;81(1):108-15.
The nature of pyrethroid resistance in Aedes aegypti Brazilian populations was investigated. Quantification of enzymes related to metabolic resistance in two distinct populations, located in the Northeast and Southeast regions, revealed increases in Glutathione-S-transferase (GST) and Esterase levels. Additionally, polymorphism was found in the IIS6 region of Ae. aegypti voltage-gated sodium channel (AaNa(V)), the pyrethroid target site. Sequences were classified in two haplotype groups, A and B, according to the size of the intron in that region. Rockefeller, a susceptible control lineage, contains only B sequences. In field populations, some A sequences present a substitution in the 1011 site (Ile/Met). When resistant and susceptible individuals were compared, the frequency of both A (with the Met mutation) and B sequences were slightly increased in resistant specimens. The involvement of the AaNa(V) polymorphism in pyrethroid resistance and the metabolic mechanisms that lead to potential cross-resistance between organophosphate and pyrethroids are discussed.
对巴西埃及伊蚊种群中拟除虫菊酯抗性的性质进行了研究。对位于东北部和东南部地区的两个不同种群中与代谢抗性相关的酶进行定量分析，结果显示谷胱甘肽 - S - 转移酶（GST）和酯酶水平有所升高。此外，在埃及伊蚊电压门控钠通道（AaNa(V)）的IIS6区域发现了多态性，该区域是拟除虫菊酯的作用靶位点。根据该区域内含子的大小，序列被分为两个单倍型组，A和B。敏感对照品系洛克菲勒只包含B序列。在野外种群中，一些A序列在1011位点存在替换（异亮氨酸/甲硫氨酸）。当比较抗性个体和敏感个体时，抗性标本中A（具有甲硫氨酸突变）和B序列的频率均略有增加。讨论了AaNa(V)多态性在拟除虫菊酯抗性中的作用以及导致有机磷和拟除虫菊酯之间潜在交叉抗性的代谢机制。
