Wolbachia endobacteria in a natural population of Culex quinquefasciatus from filariasis endemic villages of south India and its phylogenetic implication

摘要

Understanding Wolbachia mosquito interactions have been recognized as animportant concept to develop novel vector control strategies. The prevalence of Wolbachiaendobacteria in a natural population of the filariasis vector Culex quinquefasciatus wasdetermined by the polymerase chain reaction method. Earlier workers had estimated theinfection rates of Wolbachia with only one or very few individuals per species. In our studylarge number of specimens were assayed, and a total of 750 adult Culex quinquefasciatusmosquitoes were collected from three south Indian villages of Tirukoilur and Mugaiyur blocks,monthly for a period of five months (December 2006 to April 2007) and screened for thepresence of Wolbachia. The percentage prevalence in adult males ranged from 88% to 96%;while in females from 84% to 100%. An overall prevalence of 91.2% was observed. There wasno significant difference observed in the proportion of mosquitoes positive for Wolbachiabetween males and females, and also between different months of the survey; except duringthe month of February ‘07. The wsp gene sequence of the Wolbachia strain of Cx.quinquefasciatus detected was BLAST analysed and showed 99% sequence similarity withWolbachia sp. of Culex pipiens isolated from different geographical regions. Phylogeneticanalysis based on wsp gene fragments showed that the present Wolbachia isolate was closelyrelated with Wolbachia from Culex pipens pipiens, Niphotettix virescens (Order: Hemiptera)and Cnaphalocrosis medinalis (Order: Lepidoptera).