Genomic characterization of the unclassified bovine enteric virus Newbury agent-1 (Newbury1) endorses a new genus in the family Caliciviridae

Abstract

The pathogenic bovine enteric virus, Newbury agent-1 (Bo//Newbury1/1976/UK), first identified in 1976, was characterized as a possible calicivirus by morphology, buoyant density in CsCl and the presence of a single capsid protein but genomic sequence could not be obtained. In the present study, the complete genome sequence of Newbury1 was determined and classified Newbury1 in a new genus of the Caliciviridae. The Newbury1 genome, of 7454 nucleotides, had two predicted open reading frames (ORFs). ORF1 encoded the non-structural and contiguous capsid proteins. ORF2 encoded a basic protein characteristic of the family Caliciviridae. Compared to the 4 recognized Caliciviridae genera, Norovirus, Sapovirus, Lagovirus and Vesivirus, Newbury1 had less than 39% amino acid (47% nucleotide) identity in the complete 2C-helicase, 3C-protease, 3D-polymerase and capsid regions but had 89% to 98% amino acid (78% to 92% nucleotide) identity to the recently characterized NB virus in these regions. By phylogenetic analyses, Newbury1 and NB viruses formed a distinct clade independent of the 4 recognized genera. However, amino acid identities showed that Newbury1 and the NB virus were distinct polymerase types (90% amino acid identity), but their complete capsid proteins were almost identical (98% amino acid identity). Analyses of contemporary viruses showed that the two polymerase genotypes, Newbury1 and NB, were circulating in UK cattle and antibody to Newbury1-like viruses was common in cattle sera. The present study defined the existence of a new genus in the Caliciviridae that we propose be named Becovirus or Nabovirus to distinguish the new clade from bovine noroviruses.

Role of annexin A2 in cellular entry of rabbit vesivirus

“…4-8.3 kb (Kapikian et al, 1996). This family has four accepted genera, Lagovirus, Norovirus, Sapovirus and Vesivirus (Green et al, 2000), and two putative novel genera, Becovirus (Oliver et al, 2006) and Recovirus (Farkas et al, 2008), which have recently been proposed.…”

“…4-8.3 kb (Kapikian et al, 1996). This family has four accepted genera, Lagovirus, Norovirus, Sapovirus and Vesivirus (Green et al, 2000), and two putative novel genera, Becovirus (Oliver et al, 2006) and Recovirus (Farkas et al, 2008), which have recently been proposed.Studies on the replication of most caliciviruses have been hampered severely by the lack of a reliable cell-culture system. More recently, cell-culture systems have been developed for some caliciviruses such as porcine enteric calicivirus (Parwani et al, 1991), murine norovirus 1 (Wobus et al, 2004) and human noroviruses (Straub et al, 2007).…”

Genetic heterogeneity of porcine enteric caliciviruses identified from diarrhoeic piglets

“…The family includes the Vesivirus, Lagovirus, Norovirus, and Sapovirus genera as well as unassigned viruses [2]. The member viruses of each genus share a common genomic organization and a high degree of sequence similarity [2,3].…”

“…Also, antibodies to marine and terrestrial vesiviruses and vesivirus genome sequences have been detected in blood donors in the United States [13]. Animal enteric caliciviruses genetically related to human NoVs and SaVs have been detected in pigs and cows [2,[14][15][16][17][18][19][20][21]. Antibodies to human NoV have been detected in pigs and antibodies to bovine NoV have been detected in humans [22,23].…”

Molecular characterization of a porcine sapovirus strain isolated from a piglet with diarrhoea: a case report

“…Sapoviruses (SaVs), members of the genus Sapovirus, are small, non-enveloped, positive sense, single-stranded RNA viruses that belong to the family Caliciviridae (Oliver et al, 2006). Porcine SaV was first identified in a faecal sample of a diarrhoeic piglet (Sus scrofa f. domestica) by electron microscopy in the United States in 1980 (Saif et al, 1980;Guo et al, 1999) and later the pathogenic potential of porcine SaV was demonstrated in experimental infections of gnotobiotic pigs (Flynn et al, 1988;Guo et al, 2001).…”