Detection of Wolbachia sp. in Culex mosquitoes in Metro Manila, Philippines

Introduction of Wolbachia to mosquitoes is a new prospect for alternative biological control strategy to suppress the vector population and transmission of vector-borne diseases. Wolbachia is a vertically transmitted, endosymbiotic intracellular bacteria that manipulates the reproduction of its hosts. Host proliferation is suppressed by Wolbachia induced cytoplasmic incompatibility (CI), feminization, and male-killing. Due to these mechanisms, along with reduced host viral susceptibility—pathogen transmission is also restricted. This study provides evidence for the presence of Wolbachia in Metro Manila. The results have shown that 80% (12 out of 15) of the Culex mosquito (Diptera: Culicidae) sample pools were found to be positive for wsp (gene that encodes for the surface membrane protein of Wolbachia) amplification. This is an indication of the existence of Wolbachia in the mosquito populations within the cities (Las Piñas, Pasay, Pasig, Taguig, Makati) of Metro Manila. Presence of Wolbachia in these areas can potentially be employed to control vector-transmitted diseases

Detection and distribution of Wolbachia endobacteria in Culex quinquefasciatus populations (Diptera : Culicidae) from Metropolitan Manila, Philippines

© 2018 E-Flow Wolters Kluwer Medknow Publications. All rights reserved. Background & objectives: Culex quinquefasciatus is a peridomestic mosquito known for its ability to transmit pathogenic diseases such as filariasis and Japanese encephalitis. The development and use of novel and innovative vector control measures such as the utilization of Wolbachia, along with the existing ones, are necessary to prevent the transmission of these diseases. Studies exploring the diversity of Wolbachia, particularly in Cx. quinquefasciatus are very limited in the Philippines. Thus, the aim of the study was to detect the presence, distribution, and phylogenetic relationship of Wolbachia infections in Cx. quinquefasciatus in Metropolitan Manila, Philippines. Methods: Adult Cx. quinquefasciatus mosquitoes were collected using a commercially available light-trap from May 2014-January 2015. Based on their sampling grids (n = 51), the adult mosquito abdomens were pooled and subjected to Wolbachia surface protein (wsp) gene amplification assay. Five selected wsp-positive samples were then sequenced and further analyzed to infer their phylogenetic relationship with known Wolbachia strains. Results: A total of 1090 adult Cx. quinquefasciatus mosquitoes were collected. Pooled abdomens (n = 53) were then sorted based on their sampling grids for subsequent screening of wsp gene. Wolbachia infection rate was 59% (31/53). These infections were located at 29 (57%) sampling grids, and were observed to be widely distributed in the study area. Phylogenetic analysis indicated that the sample sequences were Wolbachia pipientis isolated from known hosts, Cx. pipiens and Cx. quinquefasciatus belonging to supergroup B clade. Interpretation & conclusion: The study was able to demonstrate the prevalence and distribution of Wolbachia in Cx. quinquefasciatus in Metropolitan Manila, Philippines. The findings of this study are geared towards proposing a vector control program that utilizes the potential of Wolbachia as a biological control agent in preventing the transmission of Culex-borne diseases