Cultivation and characterization of novel human group A rotaviruses with long RNA electropherotypes, subgroup II specificities, and serotype 2 VP7 genes.

During an epidemiological study of human rotavirus infections in Bangladesh, three group A strains hybridized with a serotype 2 oligonucleotide probe, but they had long RNA electropherotypes. The three strains were collected from 8- to 20-month-old infants with acute diarrhea and moderate malnutrition. By a modified isolation procedure, two strains (T-B and T-C) were adapted in MA104 cell cultures. They were identified to be subgroup II specific by enzyme-linked immunosorbent assay with subgroup I- and II-specific monoclonal antibodies and were identified by a fluorescent focus reduction neutralization assay with hyperimmune antisera to be serotype 2 specific. Further characterization of these unusual rotavirus strains needs to be carried out.