一株猪源脑心肌炎病毒的分离与鉴定

Isolation and identification of an encephalomyocarditis virus strain isolated from piglets

将江苏省某规模化猪场疑似脑心肌炎仔猪病料接种BHK-21细胞,并采用间接免疫荧光试验（IFA）、基因序列测定和动物人工感染试验进行鉴定,结果显示,BHK-21细胞接种病料样品后盲传3代出现细胞病变,病毒TCID50为10-9.2/mL;用脑心肌炎病毒（EMCV）单克隆抗体-IFA检测,在感染细胞的胞浆中可见特异性荧光;分离物的PCR扩增产物的基因序列与GenBank中的EMCV VP1基因的同源性为85.7%~99.8%;BALB/c小鼠人工感染该分离株后出现明显的临床症状和EMCV的典型病理变化,免疫组织化学试验证明,试验鼠脑组织中含有EMCV抗原,商品仔猪人工感染后未出现明显的临床症状及病理变化,证明该分离病毒为EMCV（NJ08株）,且对BALB/c小鼠具有较强的致病作用。

A strain was isolated from clinical tissue samples originated from the suspected cases with encephalomyocarditis virus（EMCV） on a pig farm in Jiangsu Province,and it was identified by IFA,RT-PCR and animal infection experiments.CPE in BHK-21 cells could be observed after three passages and the virus titer was 10-9.2TCID50/mL.The specific fluorescence was observed in the cytoplasm of BHK-21 cells infected with the strain by IFA.A VP1 gene was amplified by RT-PCR and sequenced.The VP1 gene shared 85.7% to 99.8% nucleotide identity with that reported in GenBank.An animal infection experiment showed that the strain could cause severe clinical symptoms and pathological changes in the infected BALB/c mice.The EMCV antigen could be observed in the brain tissue of the infected mice,but no obvious clinical symptoms and pathological changes were observed in the piglets infected with the strain.The results showed that this strain represented EMCV and named as EMCV NJ08.