Characterization of an antigenically distinct porcine rotavirus

A porcine virus with rotavirus morphology, which was antigenically unrelated to previously described rotaviruses, is described. Particles with an outer capsid layer measured 75 nm and those lacking the outer layer were 63 nm in diameter. Particles which resembled cores were also identified. The virus was shown to be antigenically distinct from other rotaviruses as judged by immunofluorescence and immune electron microscopy, and it failed to protect piglets from challenge with porcine rotavirus. Analysis of the genome indicated that it was composed of 11 segments of double-stranded RNA with the same overall size range as other rotaviruses but with an unusual segment pattern.