Genotype and subgentype of swine HEV
Objective To investigate the genotype and subgenotype of swine hepatitis E virus(HEV). Methods One hundred and thirty-four fecal specimens of swine under 3 months old were collected from the South Xinjiang and Liuzhou,Guangxi.HEV RNA was amplified by a reverse transcription nested polymerase chain reac- tion(RT-nPCR),and RT-nPCR products were cloned and sequenced.The nucleotide sequence comparison and phylogenetic analysis of HEV isolated from swine were carried out by using the Vector NTI Suite 9.0 and TreeView softwares.Results HEV RNA positive rates were 3.64%(2/55)in Xinjiang swine,and3.80%(3/79)in Guan- gxi swine.A total of 5 HEV RNA strains were named as XJ3-2,XJ3-6,GX3-1,GXS-2 and GX6-3.The homoge- nous profile of HEV ORF1 nucleetide sequences between XJ3-2,XJ3-6,GX3-1,GX5-2,GX6-3 and genotypeⅠ-Ⅳwas 74%-77%,76%-77%,73%-81% and 82%-98%,respectively.The nucleotide homology was 90%- 96% between ORF2 of GX5-2,XJ3-2,XJ3-6 and HEV genotypeⅣa,and 88%-95% between ORF2 of GX3-1, GX6-3 and genotypeⅣb.Conclusion The 5 HEV strains from both Xinjiang and Guangxi were classified as HEV genotypeⅣ.However,2 HEV strains isolated from Xinjiang swine belonged to subgenotypeⅣa,and HEV from Guangxi was identified asⅣa(1 strain) andⅣb(2 strains),respectively.HEV genotypeⅠand genotype m were not detected in swine feces obtained from Xinjiang and Guangxi.