Diversity of group A rotavirus of porcine rotavirus in Shandong province China.

Porcine rotavirus (PoRV) is one of the major causes of neonatal diarrhea in swine worldwide. Multiple serotypes of PoRV have been detected in diarrhea cases of suckling and weaning pigs. To date, the prevalence and molecular characterizations of PoRV circulating in swine in Shandong province of China remains largely unknown. Two hundred and twenty-six feces samples were collected from ten farms showing diarrhea in Shandong. All the samples were tested by RT-PCR for the presence of PoRV, TGEV, or PEDV. The results showed that all farms are positive for PEDV, and 60% and 10% of the farms are positive for PoRV and TGEV respectively. PoRV was detected in 65 out of 226 (28.76%) samples collected from 1-3 months old suckling and weaning pigs, while the positive rates of the TGEV and PEDV were 2.21% and 34.96%, respectively. The present data emphasized that PoRV is an important pathogen causing diarrhea in swine in China. In addition, VP6 and VP7 genes of PoRVs were sequenced and analyzed. Phylogenetical analysis of VP6 showed that all of the five PoRVs belong to group A rotavirus, meanwhile VP7 genes belong to the G3, G5, and G9 genotypes. Moreover, G5 and G9 genotypes are the dominant genotypes. Taken together, co-infections of TGEV, PEDV, and PoRV occur in pig population in Shandong, and the multiple serotypes of PoRVs are circulating in those herds, suggesting the active surveillance and matched vaccine application.