目的 了解云南农村散养猪群HEV感染情况,为HEV防控提供理论依据.方法 利用逆转录巢式聚合酶链反应(RT-nested PCR)技术,对所采集云南猪群78份粪便样品进行HEV ORF2基因部分片段扩增,经琼脂糖凝胶电泳后对目的 条带进行回收纯化及克隆测序.序列利用DNAStar和MEGA4.0软件进行同源性比较和系统进化树构建.结果 RT-nested PCR方法扩增出了350bp目的 基因序列,该序列与GenBank中HEV各型的同源性在77.4%～97.4%之间,与基因4型同源性最高(97.4%),与3型同源性最低(77.4%).系统进化树显示测定的序列与基因4型聚为一支,表明该序列属于基因4型.本次实验共检测了78份猪粪便样品,其中8份为阳性,阳性率为10.26%.结论 云南农村人群存在感染HEV的风险,应该加以防控以免HEV暴发流行.%To investigate the prevalence of swine HKV in rural areas of Yunnan province, 78 swine stool samples were collected from a village of Yunnan for HEV ORF2 detection by Reverse Transcription-nested PCR (RT-nested PCR). The PCR products were detected by electrophoresis on agarose gel and purified, and then cloned into pMD18-T vector and sequenced. The homology and phylogenetic tree were analyzed by DNAStar and MEGA 4.0, respectively. Results indicated that the expected 350 bp fragments were obtained, which shared 77. 4%- 97. 4% homologies with different HEV genotypes, 97. 4% with genotype 4 and 77. 4% with genotype 3. Phylogenetic analysis suggested that the HEV isolates in this study were clustered together with genotype 4 reference isolates, which means these isolates belonged to genotype 4. In the present study, 8 samples were positive to swine HEV, and the positive rate was 10. 26% (8/78), which indicated a high risk of HEV infection to humans through the zoonotic transmission.
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