Definition of two new groups of atypical rotaviruses.

Comparative antigenic and nuclei acid analyses were carried out on two new atypical rotavirus isolates coming respectively from chickens (D/132) and pigs (E/DC-9). Indirect immunofluorescence showed that each virus carried different group antigens which were also distinct from those of previously described rotavirus groups. By genome profile analysis each virus had a pattern of genomic RNAs clearly distinct from those of the other rotavirus groups. Comparative terminal fingerprinting of corresponding genome segments from the two viruses showed large differences between them, indicating that all of their genomic RNAs had significant differences in sequence both from each other and from the three previously defined rotavirus groups. On the basis of these results, extension of the number of rotavirus groups from three to five is proposed, with isolates D/132 and E/DC-9 being the type members of groups D and E respectively.