Genetic heterogeneity of bovine noroviruses in Italy.

By screening 104 faecal samples from asymptomatic calves in Italy, bovine norovirus RNA was detected with a prevalence rate of 10.5 % (11/104). A continuous sequence spanning the RdRp region and the 5' end of the capsid gene was generated for 7 of the 11 strains. Upon phylogenetic analysis, five strains were grouped with GIII.2 Newbury2-like viruses, and one strain was grouped with GIII.1 Jena-like noroviruses. Interestingly, one strain (80TE/IT) was genetically related to the GIII.1/Jena/80/De in the RdRp but resembled the GIII.2/Newbury2/76/UK in the capsid gene, suggesting a recombination event occurring in the ORF1/ORF2 junction region.