ABSTRACT The aim of this study was to perform the molecular characterization of conserved and variable regions of feline calicivirus capsid genome in order to investigate the molecular diversity of variants in Brazilian cat population. Twenty-six conjunctival samples from cats living in five public short-term animal shelters and three multicat life-long households were analyzed. Fifteen cats had conjunctivitis, three had oral ulceration, eight had respiratory signs (cough, sneeze and nasal discharge) and nine were asymptomatic. Feline calicivirus were isolated in CRFK cells and characterized by reverse transcription PCR target to both conserved and variable regions of open reading frame 2. The amplicons obtained were sequenced. A phylogenetic analysis along with most of the prototypes available in GenBank database and an amino acid analysis were performed. Phylogenetic analysis based on both conserved and variable region revealed two clusters with an aLTR value of 1.00 and 0.98 respectively and the variants from this study belong to feline calicivirus genogroup I. No association between geographical distribution and/or clinical signs and clustering in phylogenetic tree was observed. The variants circulating in public short-term animal shelter demonstrated a high variability because of the relatively rapid turnover of carrier cats constantly introduced of multiple viruses into this location over time.

Norovirus (NoV) infections are a major cause of acute gastroenteritis outbreaks around the world. In Brazil, the surveillance system for acute diarrhoea does not include the diagnosis of NoV, precluding the ability to assess its impact on public health. The present study assessed the circulation of NoV genotypes in different Brazilian states by partial nucleotide sequencing analysis of the genomic region coding for the major capsid viral protein. NoV genogroup II genotype 4 (GII.4) was the prevalent (78%) followed by GII.6, GII.7, GII.12, GII.16 and GII.17, demonstrating the great diversity of NoV genotypes circulating in Brazil. Thus, this paper highlights the importance of a virological surveillance system to detect and characterize emerging strains of NoV and their spreading potential.