Journal Article

Wolbachia Enhances West Nile Virus (WNV) Infection in the Mosquito Culex tarsalis

Matacchiero, Amy C., Kramer, Laura D., Rasgon, Jason L., Hughes, Grant L., Dodson, Brittany L., Paul, Oluwatobi

2014

Overview

Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain) on infection, dissemination and transmission of West Nile virus (WNV) in the naturally uninfected mosquito Culex tarsalis, which is an important WNV vector in North America. After inoculation into adult female mosquitoes, Wolbachia reached high titers and disseminated widely to numerous tissues including the head, thoracic flight muscles, fat body and ovarian follicles. Contrary to other systems, Wolbachia did not inhibit WNV in this mosquito. Rather, WNV infection rate was significantly higher in Wolbachia-infected mosquitoes compared to controls. Quantitative PCR of selected innate immune genes indicated that REL1 (the activator of the antiviral Toll immune pathway) was down regulated in Wolbachia-infected relative to control mosquitoes. This is the first observation of Wolbachia-induced enhancement of a human pathogen in mosquitoes, suggesting that caution should be applied before releasing Wolbachia-infected insects as part of a vector-borne disease control program.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Aedes / Animals / Anopheles / Antiviral agents / Bacteria / Biology and Life Sciences / Control / Culex / Culex - genetics / Culex - microbiology / Culex - physiology / Culex - virology / Culex tarsalis / Disease control / Disease transmission / Drug resistance / Ecology and Environmental Sciences / Experiments / Gene expression / Health aspects / Infections / Insect Vectors - genetics / Insect Vectors - microbiology / Insect Vectors - physiology / Insect Vectors - virology / Insects / Medicine and Health Sciences / Methods / Microbiological research / Microscopy / Mortality / Mosquito Control - methods / Mosquito Control - standards / Mosquitoes / Prevention / Science Policy / Studies / Symbiosis / Transcription Factors - genetics / Vector control / Viruses / West Nile fever / West Nile Fever - microbiology / West Nile Fever - transmission / West Nile Fever - virology / West Nile virus / Wolbachia