Study on genotypes and subgenotypes of hepatitis E virus among animals in Guangxi

ObjectiveTo detecthepatitis Evirus(HEV)and its genotypes and subgenotypes among swine,rats,dogs, Rhesus Macagues and fishes in Guangxi.Methods170 HEVantibody positive serum samples from swine,rats,and dogs,150 liver tissue samples from rats,80 fecal samples from dogs under the age of 3 months,120 bile samples from fishes,129 fecal samples from swine under the age of 3 months,and 130 fecal samples of Rhesus Macaques in Longhushan Natural Park in Guangxi were collected.HEV RNA was amplified by reverse transcription nested polymerase chain reaction(RT-nPCR), and RT-nPCR positive products were cloned and sequenced.The nucleotide sequence comparison and phylogenetic analysis of HEVfor positive samples isolated were made by using the Vector NTI Suite 9.0 and Three View Softwares.ResultsThe HEVRT-nPCR of all 170 serum samples from swine,rats and dogs were negative,and HEV RN Awas also negative among all the remaining samples,including 150 liver tissue samples from rats,120 bile samples from fishes,fecal samples from 80 dogs and 130 Rhesus Macaques.The HEV positive rate of fecal samples from swine under the age of 3 months was 10.08% (13/129).These 13 swines' HEV ORF1 nucleotide sequences islates shared similarities of 73~77%,76%~79%,76%~81%,82%~97% with genotype I-IV,respectively.Their similarities with 6 subg enotypes were 82%~94% (4a),82%~98% (4b),82%~87% (4c),81%~87% (4d),84%~86% (4f),81%~84% (4g),respectively.Among those 13 isolates,2 isolates shared the highest similarity at 82%~94% with IVa and 11 isolates shared the highest similarity at 82%~98% with IVb.ConclusionHEV strains of swine from Guangxi were classified as HEV genotype IV,2 of which were classified as HEV IVa subgenotype and 11 of which were classified as HEV IVb subgenotype.HEV was not detected positively in all serum samples from swine,rats and dogs,lver tissue from rats,fecal samples from dogs and Rhesus Mmacaques,and bile samples from fishes.