[Detection and sequences analysis of bovine hepatitis E virus RNA in Xinjiang Autonomous Region]

Reverse transcription-nested polymerase chain reaction (RT-nPCR) was used to detect HEV (Hepatitis E virus, HEV) RNA in dung or anus-swab samples collected from the cows with the positive anti-HEV antibodies in dairy farms in Xinjiang Autonomous Region. 7 of 60 (11.67%) cows were positive for HEV RNA in one farm. 1 of 31 (3.23%) cows was positive in the other farm. PCR amplification products were cloned, sequenced and analyzed. The result showed that the homology among the 8 bovine HEV ORF2 189bp nucleotide amplification sequences was 96.3%-100.0%, suggesting the same genotype. Compared with HEV genotype 1, 2, 3 and 4 corresponding 189 bp nucleotide sequences, the average homology was 78.5%-86.4%, 81.7%-83.8%, 79.1%-85.3% and 84.3%-95.8% respectively. The maximum homology between 8 nucleotide amplification sequences and one sequence of genotype 4 was 93.2%-95.8%. Based on the sequence of the nucleic acid fragments, a phylogenetic tree was constructed. It was illustrated that 8 bovine HEV ORF2 189bp nucleotide amplification sequences in this study and human C5 strain, swine swC3, swXJ strain belonged to genotype 4. The finding suggested that infection of HEV probably existed in the cow group in Xinjiang Autonomous Region and the cow might be a new animal host except swine in origin of HEV infection.