一株直径如15nm仔猪腹泻病毒的分离和鉴定

ISOLATION AND CHARACTERIZATION OF A SMALL ROUND VIRUS ABOUT 15 NM IN DIAMETER FROM THE FECES OF THE PIGLET WITH DIARRHEA

用MA-104细胞从一仔猪腹泻粪便样品分离出一株直径约15um的小圆病毒。该病毒在MA-104细胞上能极快地在约5小时内产生明显的细胞病变,并开始破坏细胞单层。用电镜观察该病毒的浓缩细胞培养物,可见多景表面有明显结构的小圆病毒,直径约15nm,没有囊膜。IF和细胞单层酶染试验显示明显的胞浆萤光和酶染,IUDR试验不抑制病毒生长,因而初步认为该病毒的核酸类型为RNA。该病毒不凝集绵羊、豚鼠和小鼠的红细胞。用对该病毒的ELISA直接双抗体夹心法检查15份仔猪腹泻样品,4份为阳性。

A small round virus about 15 nm in diameter was successfully isolated and adapted in MA-104 cells from the feccs of the piglet with diarrhea. The virus could produce the obvious CPE rather quickly, that is, in about 5 hours ( including the one-hour adsorption period ) in MA-104 cells. The CPE resulted in the rounding, ballooning and retracting of the cells. It also could infect PK-15 cells with the similiar CPE. The partially purified viruses from the harvested culture suspension were examined by EM ( IEM 100CXII ) and a large amount of the virus particles with obvious surface structure were seen,some of which seemed more deeply stained and a few looked like the doublercoated virus. IF and Cell Monolayer Enzyme Stain with the rabbit anti the virus-FITC and HRP conjugates respectively showed the distinct fluorescence and enzyme stain of the cytoplasma in the infected cells. IUDR test did not show that the replication of the virus was inhibited in MA-104 cells. Both of the results suggested that this virus is a RNA virus. The virus did not agglutinate the RBCs from sheep,mouse and guinea pig in the agglutination test. The direct sandwich ELISA to the virus was used to test 15 rotavirus-negative samples of the feces from the piglets with diarrhea; 4 of 15 were positive, including the one, from which the virus was isolated. The preliminary analysis of its RNA using 7 % FAGE showed that its RNA was single-segmented with MW of about 2.3 X 108. Further study is needed to confirm its pathogenicity and its position in virus classification.