Castrucci G, Ferrari M, Frigeri F, Cilli V, Donelli G, Angelillo G, Bruggi M
Comp Immunol Microbiol Infect Dis. 1983;6(3):253-64. doi: 10.1016/0147-9571(83)90018-8.
Nine cytopathic bovine rotavirus strains were isolated in MA-104 cell cultures from fecal specimens of dairy calves suffering from diarrhea. Isolation of the virus was accomplished from three outbreaks which occurred on dairy farms located in Central and Southern Italy. Fecal suspensions were treated with a high concentration (1000 micrograms/ml) of trypsin, and inoculated into MA-104 cell cultures grown out in Eagle's minimum essential medium (MEM) containing 5 micrograms/ml of the enzyme. Cytopathic effects (CPE), characterized by intracytoplasmic inclusion bodies of different sizes and shapes, were observed on the 1st passage with five of the strains and on the 2nd (2 strains) or the 3rd (2 strains) passage for the others. The presence of trypsin and the use of MA-104 cells appeared to be essential for the occurrence of CPE, inasmuch as no CPE was detected when trypsin was omitted in the MA-104 cell system. Replication failed to occur when primary bovine embryo kidney cell cultures with or without trypsin were used. Electron microscopy revealed the presence of particles with a typical rotavirus morphology. In MA-104 cells, the titre of virus reached its maximum 48 hr after inoculation. Small, clear-cut plaques were produced by the isolates in MA-104 cells under the overlay of MEM containing carboxymethyl cellulose, trypsin and DEAE-dextran. The nine rotavirus strains were antigenically related, whereas the relationship to either the Nebraska or the Compton rotaviruses was quite weak.
从患有腹泻的奶牛犊粪便标本中，在MA - 104细胞培养物中分离出9株具有细胞病变效应的牛轮状病毒毒株。这些病毒是从意大利中部和南部奶牛场发生的3次疫情中分离得到的。粪便悬液用高浓度（1000微克/毫升）的胰蛋白酶处理后，接种到在含有5微克/毫升该酶的伊格尔最低限度基本培养基（MEM）中生长的MA - 104细胞培养物中。5株毒株在第1代传代时观察到细胞病变效应（CPE），其特征为不同大小和形状的胞质内包涵体，另外2株在第2代传代时出现CPE，还有2株在第3代传代时出现CPE。胰蛋白酶的存在以及MA - 104细胞的使用似乎对CPE的出现至关重要，因为在MA - 104细胞系统中省略胰蛋白酶时未检测到CPE。使用添加或不添加胰蛋白酶的原代牛胚胎肾细胞培养物时，病毒无法复制。电子显微镜检查显示存在具有典型轮状病毒形态的颗粒。在MA - 104细胞中，接种后48小时病毒滴度达到最高。在含有羧甲基纤维素、胰蛋白酶和二乙氨基乙基葡聚糖的MEM覆盖下，分离株在MA - 104细胞中产生小而清晰的蚀斑。这9株轮状病毒毒株具有抗原相关性，而与内布拉斯加或康普顿轮状病毒的关系相当弱。
