Immunological and Molecular Virological Studies on Rotavirus Infection in Animals

轮状病毒（RV）是引起马驹和小牛急性腹泻的病原体之一。尽管据报道RV在动物群体中广泛传播，但RV在动物中的传播方式仍不清楚。本文研究了猪RV感染的分子病毒学和免疫学特征。(1) 1986 ~ 1991年从某轻马养殖场腹泻小马驹身上分离出一系列马rv。每一年所代表的RV都显示出相似的基因组RNA和血清型G3，表明该农场存在特定RV菌株的时间较长。然而，在1987年，一个分离株（CH3）显示出一种独特的病毒RNA电泳型（EPT），与该农场广泛流行的其他病毒不同。菌株CH3的VP7氨基酸序列与菌株G14的FI23具有高度同源性，VP4氨基酸序列与菌株H2相似。(2)上述猪场发生了小马驹G3 RV腹泻。1989年，所有的马驹在疫情期间都接种了牛初乳免疫球蛋白（Ig）粉，其发病率比1987年观察到的低，当时没有给马驹注射Ig粉。这表明Ig粉可能部分预防马驹腹泻。(3)从犊牛流行性腹泻粪便中分离出8株RV菌株。病毒rna可分为5种ept。然而，有些菌株不是单一的，而是双重或三重ept的混合构象。这些数据表明，在一头小牛中混合感染不同的rv会导致菌株之间基因组片段的重排。(4)在一个封闭的奶牛场，从1990- 1993年出生的59头小牛的222份粪便样本中，从35份（16%）分离出牛RV。3周龄犊牛IgA、IgG共抗体水平显著高于正常犊牛（P<0.05）。35株菌株中大部分是从2 ~ 6岁犊牛中分离出来的

Rotavirus (RV) is one of the causative agents of acute diarrhea in foals and calves. The mode of RV transmission among animals is still unclear, although RV has been reported to be wide-spreading in the animal populations. The present study is concerned with molecular virologic and immunologic features of RV infection in the animals. (1) A series of equine RVs was isolated from diarrheal foals in a light-horse farm from 1986 to 91. All the represented RVs in each year showed similar genomic RNA and serotype G3, suggesting the persistence of a particular RV strain in this farm for long time. In 1987, however, one isolate (CH3) showed a unique electropherotype (EPT) of viral RNA which differed from the others that widely prevailed on this farm. The VP7 amino acid sequence of strain CH3 also showed a high homology to that of G14 strain FI23, and the VP4 sequence, similar to that of strain H2, respectively. (2) Foal diarrhea with G3 RV broke out on the above-mentioned farm. In 1989, all of the foals received bovine colostral immunoglobulin (Ig) powder during the epidemic, and their morbidity was lower than that observed in 1987, when the Ig powder was not administered to foals. This suggests that the administration of Ig powder might partially prevent foal diarrhea. (3) Eight RV strains were isolated from fecal samples in epidemic diarrhea of new-born calves. Viral RNAs of the strains were classified into 5 EPTs. However, some strains presented not a single but mixed-up conformations of dual or triple EPTs. These data suggest that the mixed infection of distinct RVs in one calf cause the rearrengement of genomic segments among the strains. (4) In a closed dairy farm, bovine RV was isolated from 35 (16%) of 222 fecal specimens repeatedly collected from 59 calves born during the years 1990-93. The affected calves had IgA and IgG coproantibody levels much higher than those of normal calves 3 weeks old (P<0.05). Most of the 35 strains were isolated from calves aged 2 to 6