title: Bagaza virus inhibits Japanese encephalitis & West Nile virus replication in Culex tritaeniorhynchus & Cx. quinquefasciatus mosquitoes.
abstract: OBJECTIVE
  Studies have shown that certain flaviviruses influence susceptibility of mosquitoes by inhibiting/enhancing replication of important flaviviruses. Hence, a study was designed to determine whether Bagaza virus (BAGV), a flavivirus isolated from Culex tritaeniorhynchus mosquitoes in India, alters susceptibility of Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes to Japanese encephalitis (JEV) and West Nile viruses (WNV).
  
  
  METHODS
  JEV and WNV infection in Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes in the presence of BAGV was carried out by intrathoracic (IT) inoculation and oral feeding methods. Mosquitoes were infected with BAGV and WNV/JEV either simultaneously or in a phased manner, in which mosquitoes were infected with BAGV by IT inoculation followed by super-infection with JEV/WNV after eight days post-infection (PI). JEV and WNV yield on 7 [th] and 14 [th] day PI after super-infection was determined by 50 per cent tissue culture infective dose (TCID 50 ) method.
  
  
  RESULTS
  In Cx. tritaeniorhynchus mosquitoes, prior infection with BAGV significantly reduced JEV and WNV replication while in Cx. quinquefasciatus, BAGV influence was only seen with WNV. Reduction in virus titre was observed in IT inoculated and oral fed mosquitoes irrespective of the infection mode. JEV replication was also found reduced in Cx. tritaeniorhynchus mosquitoes persistently infected with BAGV at passage four.
  
  
  CONCLUSIONS
  BAGV infection in Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes altered their susceptibility to JEV and WNV producing low virus yield. However, the role of BAGV in inhibiting JEV/WNV replication in field mosquitoes needs further investigations.
authors.affiliation: National Institute of Virology, Microbial Containment Complex (ICMR), Pune, India.
authors.forename: A B
authors.initials: AB
authors.lastname: Sudeep
authors.forename: V P
authors.initials: VP
authors.lastname: Bondre
authors.forename: R
authors.initials: R
authors.lastname: George
authors.forename: Y S
authors.initials: YS
authors.lastname: Ghodke
authors.forename: R V
authors.initials: RV
authors.lastname: Aher
authors.forename: M D
authors.initials: MD
authors.lastname: Gokhale
mesh_terms: D000818:Animals; D003465:Culex / Q000472:pathogenicity / Q000821:virology*; D004664:Encephalitis Virus, Japanese / Q000235:genetics / Q000472:pathogenicity; D004672:Encephalitis, Japanese / Q000235:genetics / Q000635:transmission / Q000821:virology*; D005416:Flavivirus / Q000235:genetics*; D006801:Humans; D007194:India; D007303:Insect Vectors; D014779:Virus Replication / Q000235:genetics; D014901:West Nile Fever / Q000235:genetics / Q000635:transmission / Q000821:virology*; D014902:West Nile virus / Q000235:genetics / Q000472:pathogenicity