果子狸源呼肠孤病毒的分离鉴定

Isolation and Identification of A Reovirus from Masked Civet Cats (Paguma Larvata)

在广东省采集的果子狸样品共192份,处理后接种Vero-E6细胞,从中分离到1株病毒。该病毒在Vero-E6细胞上盲传至第4代开始出现细胞病变,表现为细胞内颗粒增多,细胞收缩、变圆,最后细胞从瓶壁脱落。经电镜观察发现,病毒粒子无囊膜,有双层衣壳,呈正二十面体对称,具有呼肠孤病毒的形态特征,将病毒命名为MaskedPal m Civet/China/2004(MPC/04)。红细胞凝集试验表明该病毒能凝集健康人O型血红细胞,不能凝集SPF鸡、实验用普通级牛、大鼠和豚鼠的红细胞,这与哺乳动物呼肠孤病毒血清1型的红细胞凝集谱相符。理化特性试验表明该病毒对氯仿有抵抗力;能耐受pH3.0的酸性环境;50℃水浴1h病毒未丧失感染能力;1mol/L MgCl2能提高病毒对热的抵抗力。为了进一步从分子水平上证实该病毒是呼肠孤病毒,用哺乳动物呼肠孤病毒特异性引物进行反转录-聚合酶链式反应(Reverse transcription polymerase chain reaction,RT-PCR),扩增得到了预期大小的片段。测序结果经NCBI BLAST比较,选取同源性较高者进行序列同源性分析,发现该片段与哺乳动物呼肠孤病毒血清1型参考毒株核苷酸同源性最高。以上结果证明该病毒为呼肠孤病毒科的成员。

192 samples of Masked Palm Civet （Paguma Larvata） from Guangdong Province were inoculated in Vero-E6 cells. One sample which came from masked palm Civet didn＇t cause cytopathic effects （CPE） until fourth-passage on Vero-E6 cells. Infected cells emerged granulating, shrinking, rounding and falling off. After three times freeze-thaw, cells and culture medium were harvested for electron microscopy. Virus particles were nonenveloped, double capsid and icosahedral symmetry. This virus was designated Masked Palm Civet/China/2004（MPC/04）. Hemagglutination test indicated that the virus could agglutinate healthy human type O red cells, but not the red cells of SPF chicken, experimental common bovine, rat and guinea pig. This virus was tolerant to chloroform treatment, pH3.0 and water bath 50℃ lh. 1M MgCl2 treatment could enhance resistance of virus to heat and increase infectivity. In order to classify the strain on the molecular level, specific primers according to mammalian reovirus were used for Reverse Transcription Polymerase Chain Reaction （RT-PCR）. Appropriate specific products were amplified by RT-PCR. NCBI BLAST analysis indicated that this segment shared the highest identity to mammalian reovirus serotype 1（T1L） virus. So we can deduce this virus is a member of the Reoviridae.