Astroviruses in rabbits

Abstract

By screening rabbits with enterocolitis or enteritis complex and asymptomatic rabbits, we identified a novel astrovirus. The virus was distantly related (19.3%-23.7% aa identity) in the capsid precursor to other mammalian astroviruses within the Mamastrovirus genus. By using real-time reverse transcription PCR, with specific primers and probes and targeting a conserved stretch in open reading frame 1b, we found rabbit astrovirus in 10 (43%) of 23 samples from animals with enteric disease and in 25 (18%) of 139 samples from asymptomatic animals in Italy during 2005-2008. The mean and median titers in the positive animals were 10(2)× and 10(3)× greater, respectively, in the symptomatic animals than in the asymptomatic animals. These findings support the idea that rabbit astroviruses should be included in the diagnostic algorithm of rabbit enteric disease and animal experiments to increase information obtained about their epidemiology and potential pathogenic role.

Figure

Phylogenetic trees constructed on the partial (245 aa) RNA-dependent RNA polymerase (panel A, RdRp) (open reading frame [ORF] 1b) and the full-length capsid precursor (panel B, ORF2) amino acid sequences. Black circles indicate strain identified in this study. The trees were constructed by using a selection of astrovirus (AstV) strains. Country names are abbreviated. Scale bars indicate the number of amino acid substitutions per 100 residues. Bootstrap values <90% are not shown. CSL, California sea lion; ANV, avian nephritis virus.