PREVALENCE OF G-SEROTYPE AND P-SEROTYPE AMONG EQUINE ROTAVIRUSES IN THE FECES OF DIARRHEIC FOALS

Variant types of VP4 and VP7 gene segments of faecal rotaviruses from diarrhoeic foals were identified by restriction endonuclease digestion of reverse transcription/polymerase chain reaction (RT/PCR) products. The variants observed were correlated with serotypes by determination of the sequence of representative RT/PCR products (entire coding sequ ence for VP7 and the VP8 region of VP4) and comparison to published se quences of equine G and P serotype genes. Both G and P serotypes could be predicted for 95/116(82%) strains, P serotype only for a further 8 (7%) strains and G serotype only for 1 (1%) strain. All characterised strains belonged to the same P serotype, P12, although minor sequence variations were observed. Of those strains able to be assigned to G s erotypes, 84/96 (87.5%) belonged to serotype G3A, and 12/96 (12.5%) be longed to serotype G14. Comparison of G serotyping by ELISA to the RT/ PCR method showed that serotyping equine rotaviruses by currently avai lable ELISA methods was prone to error. This study establishes the res tricted serotypic diversity of equine rotaviruses, and the significanc e of serotype G14.