Analysis by plaque reduction neutralization assay of intertypic rotaviruses suggests that gene reassortment occurs in vivo.
The SB-1A rotavirus recovered from a diarrheic piglet in the United States is a naturally occurring intertypic rotavirus. When studied by reciprocal neutralization tests, the SB-1A virus was similar, if not identical, to the porcine Gottfried virus (serotype 4) and the porcine OSU virus (serotype 5). Analysis of reassortant viruses prepared from the SB-1A virus and the serotype 2 human DS-1 virus revealed that the antigenic specificity of the outer capsid protein VP3 of SB-1A was shared with the OSU virus, while the antigenic specificity of another outer capsid protein, VP7, of SB-1A appeared to be shared with the Gottfried virus. This suggests that SB-1A is a naturally occurring reassortant rotavirus between OSU-like and Gottfried-like porcine rotaviruses. In addition, using a genetic approach, we found evidence that the fourth gene was responsible for the predominantly one-way cross-neutralizing reactivity between canine rotavirus strain CU-1 (serotype 3) and porcine rotavirus strains SB-1A (serotypes 4 and 5) and OSU (serotype 5). Assignment of hemagglutination function to the fourth genome segment of porcine rotaviruses SB-1A and OSU and canine rotavirus CU-1 confirmed a similar previous gene assignment established for certain rotaviruses. Analysis of single gene 4 substitution reassortants confirmed our previous finding that VP3 was as potent in stimulating neutralizing antibodies as VP7. The observations confirm the need for a binary system of rotavirus classification and nomenclature similar to that used for the influenza A viruses; in such a system the neutralization specificity of both VP3 and VP7 would be indicated.
D000818:Animals; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology; D002213:Capsid / Q000235:genetics* / Q000276:immunology; D004285:Dogs; D000939:Epitopes; D005814:Genes, Viral; D006387:Hemagglutination, Viral; D006801:Humans; D009500:Neutralization Tests; D011995:Recombination, Genetic; D012401:Rotavirus / Q000145:classification / Q000235:genetics* / Q000276:immunology; D012703:Serotyping; D013552:Swine; D010948:Viral Plaque Assay
D000956:Antigens, Viral; D000939:Epitopes