兰州市猪戊型肝炎血清学及病毒基因型分析

HEV sero-epidemiology and genotypes among pigs in Lanzhou city

目的调查甘肃省兰州市猪戊型肝炎病毒(HEV)感染情况以及基因型。方法收集兰州市部分地区猪血清,用ELISA诊断试剂盒分别检测HEV抗原和抗体;其中抗原阳性的血清,采用HEVORF2引物进行套式逆转录聚合酶联反应(RT-PCR)扩增,对阳性扩增产物进行克隆和测序,并对序列进行分析,确定其基因型。结果 3月以下猪戊型肝炎病毒抗原、抗体阳性率分别为1.56%和90.27%,3个月以上分别为2.35%和86.99%,抗原、抗体水平在3月龄以上和以下二者中差异无统计学意义,抗原阳性血清共有22份,其中7份为HEV核酸阳性,其核苷酸序列与HEV4型的同源性为82.2%～99.3%,分别为4a、4d和4f亚型。结论兰州市猪群存在HEV感染,且为基因4型。

Objective To investigate hepatitis E virus （HEV） sero-epidemiology and genotypes among pigs in Lanzhou city.Methods The serum samples of pigs collected from Lanzhou city were detected for anti-HEV antibody and HEV antigen with ELISA diagnostic kits.The samples positive for HEV antigen were cloned and sequenced.The sequences were analyzed with software and their genotypes and subtypes were determined.Results The positive rates for anti-HEV antibody were 90.27% and 86.99% among pigs less than 3-month-old and more than 3-month-old,respectively.While the positive rates of HEV antigen were 1.56% and 2.35%.There was no significant difference in prevalence of anti-HEV antibody or HEV antigen between the two groups.Seven of 22 antigen positive sera were positive for HEV RNA and 82.2%-99.3% of them were identical with genotype 4 at the nucleotide level belonging to subtype 4a,4d and 4f,respectively.Conclusion HEV infection among pigs exists in Lanzhou city and the strains belong to genotype 4.