Prevalence and genetic diversity of Group A and Non-Group A porcine rotaviruses in selected farms in the USAmerican Society of Virology Conference Proceedings (2012)
Fecal samples collected in different seasons of 2004 and 2011 from diarrheic and healthy nursing piglets from 5 selected swine farms in the US were screened for group (Gp) A, B and C rotaviruses (RVs) using RT-PCR. RVs were identified in 27.4% (65/237) of the samples, with 7.6%, 1.3% and 21.5% positive for Gp A, B and C RVs, respectively. An increased prevalence of Gp A and C RVs was observed between 2004 (18%) and 2011 (37%), with the highest increase for Gp C (from 11.9% to 31.1%). Seasonal effects on the prevalence of Gp A and C RVs were observed within and between the 2 years with the highest in summer (35.2%) followed by winter (27.4%). The prevalence varied among the farms and since none of them used Gp A RV vaccines, we concluded that differences in management may influence RV prevalence. Partial sequencing and phylogenetic analysis of the VP6 gene of selected Gp C RVs from different farms revealed high nucleotide sequence identity with reference human (82.5-86%) and porcine (86.2-97.2%) Gp C RVs. Historic (2004) and recent (2011) Gp C strains from two farms shared high nucleotide identity between each other (97.2-99.5%) and clustered (>92% identity) with recent Korean (2009, G6 serotype) and Brazilian strains, however, a recent Gp C RV strain from another farm was distant from Cowden, Brazilian and Korean strains or the strains from other farms. Our preliminary data on Gp A RV genotyping (VP7 gene) indicate that there are multiple genotypes of Gp A RVs currently circulating in US swine. In conclusion, our study demonstrates that infection with distinct Gp C RVs is more frequent among nursing piglets than Gp A and B RV infections.
Citation InformationJoshua O Amimo, A N Vlasova and L J Saif. "Prevalence and genetic diversity of Group A and Non-Group A porcine rotaviruses in selected farms in the US" American Society of Virology Conference Proceedings (2012)
Available at: http://works.bepress.com/joshua_amimo/17/