Molecular epidemiology of bovine rotavirus from the Charolais area (France).

Faecal samples from 164 diarrhoeic calves under 60 days of age were collect ed from the Charolais area of France during winter of 1998. The samples wer e tested by an enzyme-linked immunosorbent assay (ELISA) to detect the pres ence of rotavirus antigen. Of 164 dairy calves tested, 45.1 % were positive for rotavirus antigen. The presence of rotavirus was confirmed by electrop horesis of genomic segments. Genomic segment 9 coding for the surface glyco protein VP7 was amplified by RT-PCR using amplimeres corresponding to a con served sequence located at the 5' and 3' ends. Nucleotides of the region 29 to 320-560 (average 427) was determined by the Taq dye deoxynucleotide cyc le sequencing method. By comparison to the 175 sequences of gene 9 previous ly published, sequence analysis demonstrated that all of the isolates from the present study belong to the genotype G6. This result confirms previousl y published data indicating the prevalence of rotavirus G6 in bovine, and s uggests that a monovalent vaccine based on G6 antigen would be sufficient t o elicit a good protection. (C) Inra/Elsevier, Paris.