Determination of bovine rotavirus G and P serotypes in Italy by PCR

Determination of the G and P serotypes of group A bovine rotaviruses from 1 49 samples of feces or intestinal contents collected from calves showing cl inical signs of neonatal diarrhea was performed by a nested reverse transcr iption-PCR typing assay. The G6 serotype was the most prevalent, accounting for viruses in 55.7% of the samples; viruses of the G10 and G8 serotypes w ere found in 34.9 and 4.7% of the samples, respectively, The virus in one s ample (0.7%) was not classified due to concomitant infection with G6 and G8 strains, whereas viruses in six samples (4.0%) could not be characterized with any of the three G serotype-specific primers selected for the present study. When examined for their P-serotype specificities, viruses in 55 and 42.3% of the samples were characterized as P[11] and P[5], respectively, no P[1] serotype was identified, and viruses in 2.7% of the samples could not be classified due to multiple reactivity with both P[5]- and P[11]-specifi c primers. Various combinations of G and P serotypes were observed, the mos t frequent being G6,P[5] (38.3%), G10,P[11] (31.5%), and G6,P[ll] (15.4%). The results of the present study, while contributing to a better understand ing of the epidemiology of bovine rotaviruses in Italy, address the relevan ce of serotype specificity with regard to the constancy of the quality of b ovine rotavirus vaccines under different field conditions.