1Diarrheic fecal specimens collected from porcine herds were screened for the presence of 2 group C rotaviruses using a reverse transcription-polymerase chain reaction assay. A total of 3 188 samples were tested and 54 were positive. When compiled these data with diagnostic 4 results on group A rotaviruses and enteric caliciviruses we found that all but 5 group C 5 rotavirus positive samples contained at least one additional virus. A subset of samples were 6 subjected to nucleotide sequencing. The selected strains showed an unexpectedly wide range 7 of nucleotide sequence heterogeneity (88.6% to 100%) to each other and to the reference 8 porcine group C rotavirus strain, Cowden. The nucleotide sequence identity to the genuine 9 bovine and human strains were, respectively, 86.8% and 87.2% or less. In conclusion, our 10 study demonstrates that infection with group C rotavirus is frequent in Italian piggeries. The 11 considerable rate of multiple infections requires further studies to investigate the pathogenic 12 potential of group C rotaviruses in pigs, alone or in mixed infection, and raises challenges in 13 the laboratory diagnosis of porcine enteric infections. 14 15

Alphatronlike (genogroup IV [GIV]) noroviruses (NoVs) have been recently identified in carnivores.By screening a collection of 183 fecal samples collected during 2007 from dogs with enteric signs, the overall NoV prevalence was found to be 2.2% (4/183). A unique strain, Bari/91/07/ITA, resembled GIV.2 NoVs in its ORF1 (polymerase complex), while it was genetically unrelated in its full-length ORF2 (capsid gene) to GIV animal and human NoVs (54.0 to 54.4% amino acid identity) and to any other NoV genogroup (<54.7% amino acid identity). It displayed the highest identity (58.1% amino acid identity) to unclassified human strain Chiba/ 040502/04/Jp. Interestingly, the very 5 end of ORF2 of the canine virus matched short noroviral sequences (88.9% nucleotide identity and 98.9% amino acid identity) identified from oysters in Japan, indicating that similar viruses may be common environmental contaminants.

Astroviruses (AstVs) have been identified only occasionally in dogs. A canine AstV, strain Bari/ 08/ITA, was detected from a pup with gastroenteric signs and the virus was isolated in cell culture and characterized molecularly. In the full-length capsid protein, the virus displayed genetic similarities (83.5 % aa identity) to another canine AstV strain, although a high rate of variation occurred in the hypervariable domain, which is related to AstV antigenic specificity. Specific antibodies were detected in the convalescent dog, indicating seroconversion, and in 59 % of a collection of dog serum samples. Using primers specific for canine AstV, designed to detect a conserved region of ORF1b, canine AstVs were detected in 24.5 % of young pups with gastroenteritis, either alone or in mixed infections with other canine pathogens. In contrast, AstVs were detected in only 9.3 % of asymptomatic pups. These findings indicate that canine AstVs are common in dogs and may suggest a possible role as canine enteric pathogens. INTRODUCTIONThe family Astroviridae includes human and animal small round viruses (SRVs) with a peculiar star-like surface when observed by electron microscopy (EM). Astroviruses (AstVs) are non-enveloped and their genome is composed of a plus-sense ssRNA of 6.4-7.3 kb, containing three ORFs and a 39 poly(A) tail (Méndez & Arias, 2007). Two ORFs, located at the 59 end of the genome (ORF1a and ORF1b), encode non-structural proteins, whilst ORF2, located at the 39 end, encodes the capsid protein (Méndez & Arias, 2007). AstVs were first identified by EM in 1975 in Scotland in stools of infants hospitalized with diarrhoea (Madeley & Cosgrove, 1975). Subsequently, similar SRVs were identified from several mammalian and avian species (Bridger 1980;Englund et al., 2002;Hoshino et al., 1981; Imada et al., 2000;Kjeldsberg & Hem, 1985;McNulty et al., 1980;Snodgrass & Gray, 1977;Todd et al., 2009;Tzipori et al., 1981;Woode & Bridger, 1978), including bats (Chu et al., 2008) and aquatic mammals (Rivera et al., 2010). AstV infection is associated with gastroenteritis in most animal species, and humans AstVs are regarded as the second or third most common cause of viral diarrhoea in children (Méndez & Arias, 2007). AstVs have also been associated with extra-intestinal diseases, such as nephritis in chicken (Imada et al., 2000), hepatitis in ducks (Todd et al., 2009) and shaking syndrome in minks (Blomström et al. 2010).SRVs have been detected only occasionally in dogs by EM. In some cases, due to their morphological similarities (about 25-35 nm in size, round shape and absence of envelope), this definition has been used to refer to AstV-, calicivirus-or picornavirus-like particles. AstV-like particles were first detected in beagle pups with diarrhoeal disease in the USA in 1980 in a mixed infection with canine parvovirus type 2 (CPV-2) and canine coronaviruses (CCoVs) (Williams, 1980). AstV-like particles were also detected in 3/157 normal faecal samples (but not in 29 diarrhoeal samples) in a survey in Australia ...

Evidence for a possible zoonotic role of group C rotaviruses (GCRVs) has been recently provided. To gain information on the genetic relationships between human and animal GCRVs, we sequenced the VP7 gene of 10 porcine strains detected during a large surveillance study from different outbreaks of gastroenteritis in piglets. Four GCRV strains were genetically related to the prototype GCRV porcine Cowden strain. A completely new VP7 genotype included 4 strains (344/04-7-like) that shared 92.5% to 97.0% aa identity to each other, but <83% to human GCRVs and <79% to other porcine and bovine GCRVs. A unique 4-aa insertion (SSSV or SSTI), within a variable region at the carboxy-terminus of VP7, represented a distinctive feature for these 4 unique strains. An additional strain, 134/04-18, was clearly different from all human and animal GCRVs (<85% aa identity) and likely accounts for a distinct VP7 genotype. The VP7 of a unique strain, 42/05-21, shared similar ranges of aa sequence identities with porcine and human strains (88.0-90.7% to porcine GCRVs and 85.2-88.2% to human GCRVs). Plotting the VP7 gene of strain 42/05-21 against the VP7 of human and porcine strains revealed discontinuous evolution rates throughout the VP7 molecule, suggesting different mutational pressure or a remote intragenic recombination event. These findings provide the need for future epidemiological surveys and warrant studies to investigate the pathogenic potential of these novel GCRVs in pigs.

Infection by a novel canine astrovirus was associated with gastroenteritis in two dogs. The virus displayed 70.3 to 73.9% amino acid identity to other canine astroviruses in the full-length capsid. Specific antibodies were detected in the convalescent-phase sera of the dogs, indicating seroconversion. Also, the virus appeared weakly related antigenically to the prototype canine astrovirus isolate ITA/2008/Bari.

A novel astrovirus was found more frequently in rabbits with enteric disease than in asymptomatic animals.

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SUMMARYThe study investigated the genetic diversity of human astroviruses (HAstVs) detected in children hospitalized with gastroenteritis in Italy in 2008–2009. A total of 1321 faecal samples were collected in Parma (northern Italy), Bari (southern Italy), and Palermo (Sicily) and screened for the presence of HAstVs. RT–PCR amplification of a portion at the 5′-end of ORF2 allowed the detection of HAstVs in 3·95% of the patients. Four different genotypes (HAstV-1, HAstV-2, HAstV-4, HAstV-5) were found to be circulating during the study period, with HAstV-1 being the predominant type. Interestingly, a novel lineage, proposed as HAstV-2d, was found to have emerged in Parma in 2009. Investigating the genetic variability of HAstVs will be important for understanding the epidemiological trends and evolution of these viruses.