Tecnologias de georreferenciamento e genética molecular aplicados à avaliação da resistência de Aedes (Stegomyia) aegypti (L.) (Diptera: culicidae) ao Temefós

Abstract

The frequent use of temephos has resulted in development of insecticide resistance in Aedes aegypti, compromising control and favoring the transmission of diseases transmitted by him. This study aimed to obtain information on temephos resistance of A. aegypti collected in the municipalities of Paraíba, aiming to support health workers to develop strategies to monitor and control the populations of this vector. The twenty-four populations were collected in the towns of Alagoa Grande, Alagoa Nova, Campina Grande, Esperança, LagoaSeca e Serra Redonda, where eggs were collected using ovitraps from neighborhoods with high levels of vector infestation - area A neighborhoods and equidistant at 500 m, 1,000 m and 1,500 m away from the area, constituted the areas B, C and D, respectively. The eggs were taken to the laboratory for mosquito breeding, identification and determination of the index for Oviposition Trap (IAO). Geographical coordinates of each collection point were obtained, mounted an array of geographical distance with the number of blocks, the total number of residences and/or establishments positive or not. The laboratory bioassays were conducted from temephos, which was determined with the diagnostic dose. The homogenate protein L4 larvae was subjected to electrophoresis on 7.5% polyacrylamide gels. In this study we found that the IAO was high, above 20%. The highest incidence of vector was found for the Catolé district, area C of the City of Esperança with IAO 90%. All populations underwent diagnostic dose of 0.352 mg de i.a./L, where we had 0% mortality. Most LC90 was found in the city of Alagoa Nova, about thirty-eight times the value of LC90 to the susceptible population (Rockefeller - default). All populations showed RR bigger than 20, therefore is considered highly resistant. The esterase activity was visualized using the substrates α and β-naphthyl acetate, allowed the visualization of six regions of α and β-esterase, called EST- 1 EST- 6. The populations characterized as resistant showed two to six regions of esterase activity, whereas the susceptible population was viewed only one region of activity.