A lack of consistent amino acid substitutions in NSP4 between rotaviruses derived from diarrheal and asymptomatically-infected kittens

Nonstructural glycoprotein NSP4 of group A rotavirus has recently been show n to be a viral enterotoxin, inducing diarrhea in neonatal mice, Literature is conflicting as to whether there is any consistent amino acid substituti on between virulent (or symptomatic) and attenuated (or asymptomatic) rotav irus strains. We have sequenced and compared the NSP4 sequences derived fro m a total of 10 geographically and serologically-related feline rotavirus s trains from both diarrheal and asymptomatically-infected kittens. These NSP 4 sequences were closely related to each other and there were differences a t 19 amino acid residues, but none was segregated according to whether the strain was isolated from a diarrheal kitten or not. Thus, this study failed to lend support to the contention that mutations in NSP4 play a significan t role in the pathogenesis of rotavirus diarrhea, Involvement of other gene s may explain the outcome of infection in cats from which these 10 feline r otaviruses were isolated.