Culture adaptation of serotype G6 human rotavirus strains from hospitalized diarrhea patients in India.

During serotyping of fecal specimens positive for rotavirus from hospitalized diarrhea patients in Pune, India, about 10% showed multireactivity in enzyme immunoassay with monoclonal antibodies specific for serotypes G1-4, 6, 8, and 10. In order to characterize some of these, three fecal specimens from children and one from adult were culture adapted. All the isolates showed long RNA pattern, but three out of four isolates belonged to subgroup I and II and one, to subgroup I. The isolates were confirmed as G6 by neutralization assay and polymerase chain reaction. Nucleotide sequences of cDNA derived from the gene encoding the outer capsid protein, VP7 of two strains indicated >94% identity with G6, the serotype, generally associated with cattle. The isolates were more close to G6 RF strain, which is a bovine rotavirus, reported from France. This is a first report of isolation of bovine serotype, G6 from children as well as adults from India.