The Bovine Newbury Agent-2 Is Genetically More Closely Related to Human SRSVs Than to Animal Caliciviruses

Abstract

The hypothesis that the enteric bovine calici-like virus Newbury agent (NA-2) belongs to the family Caliciviridae was examined by genome sequence analysis. Use of solid-phase immune electron microscopy allowed samples with good levels of virus to be identified and amplification of the genome was achieved by reverse transcription-polymerase chain reaction. Examination of a 216-amino-acid sequence in the RNA-dependent RNA polymerase gene and a 116-amino-acid sequence in the capsid gene showed that NA-2 had the closest deduced amino acid identity (77 to 80% for the polymerase region and 67 to 73% for the capsid region) to the morphologically indistinguishable human SRSVs (small round structured viruses) of genogroup 1, which are classified as members of the Caliciviridae. It had a weak relationship (<34.5% deduced amino acid identity) in both the polymerase and the capsid regions to animal caliciviruses, all of which have classical morphology. This is the first genomic data from a nonhuman virus with SRSV morphology. It confirms the hypothesis that the bovine enteric calici-like virus NA-2 is a member of the family Caliciviridae and endorses the observation to date that viruses with SRSV morphology are genomically distinct.

Evidence for airborne transmission of Norwalk-like virus (NLV) in a hotel restaurant

“…NLVs have the ability to cause outbreaks of gastrointestinal infection characterized by vomiting which is often sudden and projectile [3], as well as diarrhoea. Human NLVs have no known reservoir outside of man [4] although animal NLVs have been reported recently [5,6].…”

Genetic classification of "Sapporo-like viruses"

“…The members of the genera "Sapporo-like viruses" (SLVs) and "Norwalk-like viruses" (NLVs) in the family Caliciviridae [14,32] are an important cause of gastroenteritis in humans [4,8,10,12,21,28,30,39,40,43] and animals [7,15,26,38]. In humans, the illnesses caused by SLVs and NLVs differ in epidemiological features and clinical symptoms.…”

Characterization of a Rhesus Monkey Calicivirus Representing a New Genus of Caliciviridae

“…Based on phylogenetic analysis, both HuCV genera are further divided into five genogroups (GI to GV) and several genetic clusters or genotypes (9,42). Viruses genetically and antigenically closely related to HuCVs have also been isolated from animals (6,18,21,36), which has raised a concern about CV gastroenteritis as a zoonotic disease and the role of animals as reservoirs for HuCVs. Since there is no effective tissue culture system or animal model available for HuCVs, animal CVs are often used as surrogates to model HuCV stability in the environment (7,8,37), replication (2,3), and pathogenesis (40).…”