Analyses of clinical, pathological and virological features of human rotavirus strain, YO induced gastroenteritis in infant BALB/c mice.

Experimental studies of human rotavirus infections in mice are limited and there is lack of information on the quantitative assessment of rotaviral replication and its relationship with histological changes. In the present study, consequences of human rotavirus strain, YO induced gastroenteritis in infant BALB/c mice were analyzed for the occurrence of clinical symptoms, histopathology and virological events. The infected animals developed diarrhea and dehydration and showed accumulation of vacuolated enterocytes with lodging of the rotavirus antigens and shortening of villi in the intestine over a period of 5 days. The ileum was identified as the most susceptible and supportive part of small intestine for perpetuation of rotavirus infection in mice. Rotaviral antigen/RNA in stool and RNA in intestine were detected throughout the clinical disease period. At 48-72 h post inoculation, diarrhea was at the peak (90-95%) in the infected animals with increased load of viral RNA and intense pathological lesions suggesting it as the critical time point in the course of infection. The rising titers of antirotavirus neutralizing antibodies ascertained the replication of human rotavirus strain, YO in mice. These data may contribute to the understanding of pathophysiological, immunological and virological characteristics of rotavirus infections in mice.