title: Tissue tropism and molecular characterization of a Japanese encephalitis virus strain isolated from pigs in southwest China.
abstract: Since September 2012, an epidemic has been spreading among swine in a pig farm located in Sichuan province, southwest China, which has resulted in abortion, stillbirth, and fetal mummification. The brains of stillborn pigs were collected and a previously unknown Japanese encephalitis virus (JEV), namely SCYA201201, was isolated. According to the results of agarose gel diffusion precipitation, indirect immunofluorescence analysis, neutralization testing, reverse transcription PCR (RT-PCR) amplification, and physical and chemical testing, the virus was conformed to have the characteristics of JEV. The virus titer in BHK-21 cells was 10(8.47)PFU/ml and the median lethal dose (LD50) to 3-week-old and 7-day-old mice was 1.99 log10 and 1.02 log10 PFU/LD50, respectively. The results of tissue tropism for mice showed that the viral load in the brain was significantly higher than other organs, indicating that the isolate was strongly neurotropic. Additionally, the complete genome sequence of the isolate was determined and compared with other JEV strains. Phylogenetic analysis showed that the isolate belongs to genotype I and may be an imported virus. The isolate had 88.4% nucleotide identity with the Chinese vaccine strain SA14-14-2. However, there were 69 amino acid substitutions compared with the strain SA14-14-2. Some substitutions indicated that SCYA201201 was highly neurovirulent and infective, in accordance with the results of animal testing.
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Lei
authors: L
authors: Yuan
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Rui
authors: R
authors: Wu
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Hanyang
authors: H
authors: Liu
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Xintian
authors: X
authors: Wen
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Xiaobo
authors: X
authors: Huang
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Yiping
authors: Y
authors: Wen
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Xiaoping
authors: X
authors: Ma
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Qigui
authors: Q
authors: Yan
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
authors: Yong
authors: Y
authors: Huang
authors: College of Food Science, Sichuan Agricultural University, Ya'an 625014, China.
authors: Qin
authors: Q
authors: Zhao
authors: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; Laboratory of Zoonosis, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China. Electronic address: sdrcenter@sina.com.
authors: Sanjie
authors: S
authors: Cao
mesh_terms: D000818:Animals; D001921:Brain / Q000821:virology; D055598:Chemical Phenomena; D002681:China / Q000453:epidemiology; D004664:Encephalitis Virus, Japanese / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology*; D004672:Encephalitis, Japanese / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D058872:Epidemics; D005455:Fluorescent Antibody Technique; D016679:Genome, Viral; D005838:Genotype; D007928:Lethal Dose 50; D051379:Mice; D009500:Neutralization Tests; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology*; D019562:Viral Load; D056189:Viral Tropism
keywords: Isolate; Japanese encephalitis virus; Molecular characterization; Tissue tropism