title: Wolbachia enhances West Nile virus (WNV) infection in the mosquito Culex tarsalis.
abstract: 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.
authors.affiliation: Department of Entomology, Pennsylvania State University, University Park, Pennsylvania, United States of America; Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Brittany L
authors.initials: BL
authors.lastname: Dodson
authors.affiliation: Department of Entomology, Pennsylvania State University, University Park, Pennsylvania, United States of America; Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, United States of America; Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Grant L
authors.initials: GL
authors.lastname: Hughes
authors.affiliation: Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland, United States of America.
authors.forename: Oluwatobi
authors.initials: O
authors.lastname: Paul
authors.affiliation: Arbovirus Laboratories, Wadsworth Center, New York State Department of Health, Slingerlands, New York, United States of America.
authors.forename: Amy C
authors.initials: AC
authors.lastname: Matacchiero
authors.affiliation: Arbovirus Laboratories, Wadsworth Center, New York State Department of Health, Slingerlands, New York, United States of America; School of Public Health, State University of New York at Albany, Albany, New York, United States of America.
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kramer
authors.affiliation: Department of Entomology, Pennsylvania State University, University Park, Pennsylvania, United States of America; Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, United States of America; Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Jason L
authors.initials: JL
authors.lastname: Rasgon
mesh_terms: D000818:Animals; D003465:Culex / Q000235:genetics / Q000382:microbiology / Q000502:physiology / Q000821:virology; D007303:Insect Vectors / Q000235:genetics / Q000382:microbiology / Q000502:physiology / Q000821:virology; D009032:Mosquito Control / Q000379:methods / Q000592:standards; D013559:Symbiosis; D014157:Transcription Factors / Q000235:genetics; D014901:West Nile Fever / Q000382:microbiology / Q000635:transmission* / Q000821:virology; D014902:West Nile virus; D020577:Wolbachia
chemical_list: D014157:Transcription Factors