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Canine bufavirus (CBuV) is a protoparvovirus, genetically related to human and non-human primate bufaviruses and distantly related to canine parvovirus type 2 (CPV-2). CBuV was initially identified from young dogs with respiratory signs but subsequent studies revealed that this virus is also a common component of the canine enteric virome. In this survey, by assessing archival and recent collections of dogs faecal samples, CBuV DNA was detected with a higher prevalence rate (8.8%) in animals with enteritis than in control animals (5.0%), although this difference was not statistically significant. The rate of co-infections with other enteric viruses in diarrhoeic dogs was high (84.6%), mostly in association with canine parvovirus CPV-2 (90.1%). The complete ORF2 gene was determined in five samples, and the nearly full-length genome was reconstructed for three strains, 62/2017/ITA, 9AS/2005/ITA and 35/2018/ITA. Upon sequence comparison, the viruses appeared highly conserved in the NS1 (97.2%-97.9% nt and 97.5%-98.1% aa identities). In the complete VP2 coding region, three strains were similar to the prototype viruses (99.7-99.8 nt and 99.6%-99.8% aa) whilst strains 9AS/2005/ITA and 35/2016/ITA were distantly related (87.6%-89.3% nt and 93.9%-95.1% aa identities). Interestingly, genetic diversification occurred downstream conserved regions such as the VP1/VP2 splicing signals and/or the G-rich motif in the N terminus of the VP2, suggesting a potential recombination nature. Upon phylogenetic analysis, the two divergent CBuV strains formed a distinct cluster/genotype., (© 2020 Blackwell Verlag GmbH.)

Caliciviruses of the Sapovirus genus have been recently detected in dogs. Canine sapoviruses (SaVs) have been identified in the stools of young or juvenile animals with gastro-enteric disease at low prevalence (2.0-2.2%), but whether they may have a role as enteric pathogens and to which extent dogs are exposed to SaVs remains unclear. Here, we report the expression in a baculovirus system of virus like-particles (VLPs) of a canine SaV strain, the prototype virus Bari/4076/2007/ITA. The recombinant antigen was used to develop an enzyme-linked immunosorbent assay (ELISA). By screening an age-stratified collection of serum samples from 516 dogs in Italy, IgG antibodies specific for the canine SaV VLPs were detected in 40.3% (208/516) of the sera. Also, as observed for SaV infection in humans, we observed a positive association between seropositivity and age, with the highest prevalence rates in dogs older than 4 years of age., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Molecular and serological data suggest that noroviruses (NoVs) might be transmitted between humans and domestic carnivores. In this study we screened an age-stratified collection of canine sera (n=516) by using an ELISA assay based on virus-like particles (VLPs) of human NoVs GII.4 and GIV.1 and carnivore NoVs GIV.2 and GVI.2. Antibodies against GII.4 and GIV.1 human NoVs and GIV.2 and GVI.2 NoVs from carnivores were identified in dog sera (13.0%, 67/516) suggesting their exposure to homologous and heterologous NoVs. Analysis of the trends of age-class prevalence showed a gradual increase in the positive rate from 9.0% and 7.0%, in young dogs <1year of age to 15.0% in dogs older than 12 years, for GII.4 and GVI.2 NoVs, respectively. A significant difference in the IgG distribution by age classes was observed for GIV.1 NoVs, with the highest rate of antibodies (7.0%) in the age group <1year and the lowest (1.0%) in the age-classes 7-9 (P=0.049). High correlation between the reactivity to GII.4 and GVI.2 NoVs was observed, likely due to conserved epitopes in the capsid structure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In 2003, a novel calicivirus, the vesivirus (VeV) strain 2117, was identified incidentally as a contaminant in Chinese Hamster Ovary (CHO) cell cultures by a German pharmaceutical company. Similar contaminations have been documented in three additional episodes, in bio-reactors used for production of recombinant drugs. More, recently 2117-like VeVs have also been identified at high prevalence in the stools from asymptomatic kennel dogs and only sporadically in diarrhoeic and healthy household dogs. In this study, antibodies for 2117-like viruses were detected in 21.5% of sera from household dogs, indicating that they are common viruses in the canine host., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Caliciviruses are important human and animal pathogens. Novel caliciviruses have been identified recently in dogs, raising questions about their pathogenic role and concerns regarding their zoonotic potential. By screening stool samples of young or juvenile dogs using RT-PCR assays, sapoviruses (SaVs) were found in 7/320 (2.2%) samples of animals with acute gastroenteritis while they were not detected in healthy animals (0/119). The sequence of a nearly 3kb portion at the 3' end of the genome, encompassing the RNA-dependent RNA polymerase (RdRp), the capsid region (ORF1) and the ORF2 were determined for three strains. A distinctive genetic feature in canine SaVs was a 4-nucleotide (nt) interval between the ORF1 and ORF2. Two strains (Bari/4076/07/ITA and Bari/253/07/ITA) were very closely related in the RdRp and capsid regions to the strain AN210D/09/USA (90.4-93.9% nt), while strain Bari/5020/07/ITA displayed only 71.0-72.0% nt identity to this group of canine SaVs and 76.0% to strain AN196/09/USA. Overall, these findings indicate that the canine SaVs detected in Italy may represent distinct capsid types, although all currently known SaVs segregate into the novel proposed genogroup, tentatively named as GXIII., (Copyright © 2015 Elsevier B.V. All rights reserved.)