Resistance of Aedes aegypti (Diptera: Culicidae) in 2006 to pyrethroid insecticides in Indonesia and its association with oxidase and esterase levels.

Three strains of Aedes aegypti collected in 2006 from three major cities in Indonesia, i.e., Bandung, Palembang and Surabaya, were tested to determine their resistance status to pyrethroid (permethrin and deltamethrin) and also the resistance mechanisms regarding three detoxifying enzymes, i.e., oxidase, esterase A and esterase B. The resistance level was expressed as Resistance Ratio (RR) compared to the susceptible VCRU strain. Results of this study showed that Ae. aegypti in Indonesia has developed tolerance to permethrin and deltamethrin, except in the Bandung strain, which was resistant to permethrin and deltametherin with RR90 79.3 and 23.7, respectively. The study also suggested that detoxifying enzymes (oxidase, esterase A and esterase B) apparently were involved in the development of resistance in Bandung strain as indicated by the high level of activity of those enzymes in Bandung strain compared to other more susceptible strains. Although there is a possibility that other mechanisms, such as a target-site resistance mechanism, in Bandung strain were also involved.