Molecular Survey and Genetic Identification of Wolbachia Endosymbionts in Dwelling-Caught Culex quinquefasciatus (Diptera: Culicidae) Mosquitoes from Taiwan.

The genetic identity of Wolbachia endosymbionts was determined in dwelling-caught Culex quinquefasciatus from Taiwan. A total of 370 Cx. quinquefasciatus (245 females and 125 males) was initially screened for Wolbachia infection targeting the universal 16S gene, and the positive samples were further identified their genogroup by a nested-polymerase chain reaction assay to amplify the group-specific Wolbachia surface protein (wsp) gene. In general, 44.59% of Cx. quinquefasciatus was detected with Wolbachia endosymbionts, and 43.2% (54/125) in male and 45.31% (111/245) in female. The group-specific detection was observed in 2.16% (8/370), 41.35% (153/370), and 1.08% (4/370) with groups A, B, and co-infection (A&B), respectively. Phylogenetic analysis revealed that the genetic identities of these Taiwan strains were genetically similar to the groups A and B of Wolbachia with the high sequence homogeneity of 98.7-100% and 96.5-99.8%, respectively. Genetic relatedness is clearly discriminated using both methods of maximum likelihood (ML) and unweighted pair group with arithmetic mean (UPGMA). This study demonstrates the initial genetic identity of Wolbachia endosymbionts with a low prevalence (2.16%) of group A and a high prevalence (41.35%) of group B in dwelling-caught Cx. quinquefasciatus of Taiwan. Because the Cx. quinquefasciatus had been known as a vector for various viral pathogens, the possible impacts of Wolbachia endosymbionts on vector competence of Cx. quinquefasciatus in Taiwan need to be further identified.