title: Pathogenic and Genotypic Characterization of a Japanese Encephalitis Virus Isolate Associated with Reproductive Failure in an Indian Pig Herd.
abstract: BACKGROUND
  India is endemic to Japanese encephalitis virus (JEV) and recurrent outbreaks occur mainly in rice growing areas. Pigs are considered to be the amplifying host for JEV and infection in gestating pigs results in reproductive failure. Most studies conducted on JEV infection in Indian pigs have been serological surveys and very little is known about JEV genotypes circulating in pigs. So the potential risk posed by pigs in JEV transmission and the genetic relationship between viruses circulating in pigs, mosquitoes and humans is poorly understood.
  
  
  RESULTS
  This study was conducted in pigs with a history of reproductive failure characterized by stillborn piglets with neuropathological lesions. Japanese encephalitis (JE) suspected brain specimens inoculated intracerebrally into mice and Vero cells resulted in successful isolation of JEV/SW/IVRI/395A/2014. Clinicopathological observations in infected mice, demonstration of JEV antigen in brain, and analysis of the envelope protein identified the swine isolate as being neurovirulent. Phylogenetic analysis based on prM and E gene sequences showed that it belonged to genotype III. This swine isolate was closely related to JEV associated with the 2005 outbreak in India and JaoArS982 from Japan. Phylogenetic analysis of JEV strains collected between 1956 and 2014 in India categorized the GIII viruses into different clades blurring their spatial distribution, which has been discernible in the previous century.
  
  
  CONCLUSIONS
  Isolation of JEV from stillborn piglets and its close genetic relationship with viruses detected at least three decades ago in humans and mosquitoes in Japan suggests that the virus may have been circulating among Indian pigs for several decades. The close similarity between the present swine isolate and those detected in humans affected in the 2005 outbreak in Uttar Pradesh, India, suggests the need for more intensive surveillance of pigs and implementation of suitable strategies to control JE in India.
authors.affiliation: Swine Disease Lab, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: P A
authors.initials: PA
authors.lastname: Desingu
authors.affiliation: Swine Disease Lab, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Ray
authors.affiliation: Division of Livestock Production and Management, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: B H M
authors.initials: BH
authors.lastname: Patel
authors.affiliation: Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: R
authors.initials: R
authors.lastname: Singh
authors.affiliation: Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: R K
authors.initials: RK
authors.lastname: Singh
authors.affiliation: Swine Disease Lab, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, 243122.
authors.forename: G
authors.initials: G
authors.lastname: Saikumar
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D004664:Encephalitis Virus, Japanese / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D004672:Encephalitis, Japanese / Q000662:veterinary*; D005838:Genotype; D051379:Mice; D010802:Phylogeny; D012098:Reproduction; D012641:Selection, Genetic; D050497:Stillbirth; D013552:Swine; D013553:Swine Diseases / Q000503:physiopathology* / Q000821:virology*; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins