Multiple-gene rotavirus reassortants responsible for an outbreak of gastroenteritis in central and northern Australia

Two rotavirus strains, E210 and E212, implicated in epidemics of gastroenteritis in children in central and northern Australia during 1993-1994, exhibited the unusual combination of a 'short' RNA electrophoretic pattern and subgroup II specificity. The outer capsid protein VP7 was found by PCR typing and sequence analysis to be related to that of serotype G2 viruses. Both strains displayed a novel pattern of reactivity to G2-specific monoclonal antibodies that correlated with sequence variation in the antigenic regions of VP7. The VP4 serotype of E210 and E212 was determined as P1B in an enzyme immunoassay, consistent with other G2 viruses. Analysis of the VP6 gene indicated significant identity (98-99%) with other human subgroup II viruses. Northern hybridization analysis of E210 RNA using total genome probes derived from the prototype strains RV4 and RV5 indicated that E210 was derived from multiple gene reassortment between rotaviruses belonging to different genetic types.