Detection of kdr mutations in southern house mosquitoes using allele specific PCR

Mosquito-borne disease is the number one killer worldwide with an average death toll in the millions each year. Mosquito control is the most successful strategy for the suppression of mosquito borne diseases. Mosquito control strategies depend heavily on insecticides. Pyrethroids are currently the most widely used insecticides for the indoor control of mosquitoes. Southern house mosquito Culex quinquefasciatus is a major vector of filariasis and various encephalitis in U.S. and worldwide. In Texas, Southern house mosquitoes have become major targets of pyrethroid insecticides. However, the heavy use of pyrethroids has led to the development of resistance among mosquito populations in many counties in Texas. Knock-down resistance due to a point mutation (designated the L to F kdr mutation) in the voltage gated sodium channel is a common mechanism of resistance to pyrethroids. Simple and reliable techniques are in great need to detect and monitor pyrethroid resistance among mosquito populations in the field. In this study, we have found the presence of the L to F kdr mutation in several field populations of Culex quinquefasciatus. More significantly, for the first time, we have developed a reliable allele specific polymerase chain reaction (AS-PCR) method to detect the L to F kdr mutation in the mosquito Culex quinquefasciatus.