Variation in neutralization epitopes of human rotaviruses in relation to genomic RNA polymorphism.

Fecal rotaviruses collected from October 1983 to September 1984 from outpatients and inpatients attending the Royal Children's Hospital, Melbourne, Australia, with acute gastroenteritis were serotyped by enzyme immunoassay using rotavirus-neutralizing mouse monoclonal antibodies specific for serotypes 1 to 4. Application of three different serotype 1-neutralizing antibodies indicated variations in neutralization epitopes between serotype 1 rotaviruses on the major outer capsid glycoprotein, including a site shared with serotype 3 rotaviruses. The three different binding patterns observed were termed "monotypes." Comparison of monotype and serotype with genomic RNA profiles generated by gel electrophoresis of ds viral RNA indicated that each RNA electropherotype corresponded to only one monotype (1a, 1b, 1c) or serotype (3, 4). However, serotypes 1 (a and c) and 4 contained multiple electropherotypes. Greater numbers of RNA segment variations, including alteration in mobility of gene segments 7, 8, and 9, were evident between rotaviruses of different serotype or monotype than within those groups. Within limits of time and location, rotavirus neutralization epitope variations appear to correlate with RNA polymorphism. Where rotavirus epidemiology has been analyzed by year using RNA electropherotypes, only limited numbers of each RNA pattern need to be serotyped to ascertain the major serotypes in circulation.