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Canine parvovirus type 2 (CPV-2) infection is associated with severe gastroenteritis in puppies. Quantification of CPV-2 specific antibodies before vaccination can reveal the presence of interfering maternal-derived immunity and facilitate timing of effective immunisation. Inhibition of haemagglutination (HI) is commonly used to measure CPV-2-specific antibody levels in serum. However, the presence of nonspecific agglutinins in canine serum and artefactual precipitation of red blood cells (RBC) are both limitations of the assay. In this study, we compared the standard HI protocol with a refined HI protocol, in which canine serum was pre-incubated with porcine RBC for 12 h to remove nonspecific agglutinins and a lower concentration (0.1% vs. 0.8%) of porcine RBC suspensions was used to limit artefactual precipitation of RBC. A panel of canine sera, collected from 80 dogs of different ages and with different neutralising antibody titres, was analysed. Nonspecific agglutinins were identified in most (97%) serum samples from puppies4 months of age and in only 7% dogs 6 months old. Pre-treatment of serum samples was effective in removing nonspecific agglutinins from all samples and artefactual precipitation of RBCs was not noted when 0.1% RBC suspensions were used. Refinement of the HI protocol has increased the accuracy of interpretation and reduced the interference of nonspecific agglutinins, primarily seen in puppies. This reduces the likelihood of incorrect assessment of passive or active immunity in puppies when deciding whether to administer or defer vaccination, which could potentially leave them susceptible to CPV-2 infection.

Canine distemper virus (CDV) is a major infectious disease of dogs. Although vaccines were successful to control CDV spread in canine population, the disease is still common and may pose a threat to unvaccinated dogs. In the attempt to develop specific anti-viral therapeutic tools, the efficacy of several molecules against CDV has been investigated in vitro. In this study the antiviral efficacy in vitro against CDV of ribavirin and boceprevir alone or in combination was evaluated. CDV growth in VERO cells was inhibited by ribavirin, by boceprevir and by a combination of the two molecules at non-cytotoxic concentrations, as evaluated by end-point viral titration in cell monolayers and by quantification of viral RNA using quantitative RT-PCR. By end-point titration, a statistically significant reduction in CDV replication was observed only using ribavirin and boceprevir in combination. By quantitative RT-PCR, a significant reduction of viral growth was observed either in cells treated with ribavirin or boceprevir or with both the two molecules. The association of ribavirin or boceprevir was able to decrease CDV growth by up to 3.4458 logs with respect to untreated infected cells, chiefly at the highest virus dilutions. The results obtained in this study may constitute an important basis for the development of CDV therapies.

A novel protoparvovirus species was identified in domestic cats. The virus was distantly related to the well-known feline (feline panleukopenia virus) and canine (canine parvovirus type 2) parvoviruses, sharing low nucleotide identities in the capsid protein 2 (less than 43%). The virus was genetically similar (100% at the nucleotide level) to a newly identified canine protoparvovirus, genetically related to human bufaviruses. The feline bufavirus appeared as a common element of the feline virome, especially in juvenile cats, with an overall prevalence of 9.2%. The virus was more common in respiratory samples (9.5%-12.2%) than in enteric samples of cats (2.2%). The role of bufaviruses in the etiology of feline respiratory disease complex, either as a primary or a secondary agents, should be defined.

Since it first emergence in the mid-1970's, canine parvovirus 2 (CPV-2) has evolved giving rise to new antigenic variants termed CPV-2a, CPV-2b and CPV-2c, which have completely replaced the original strain and had been variously distributed worldwide. In Africa limited data are available on epidemiological prevalence of these new types. Hence, the aim of the present study was to determine circulating variants in Morocco. Through TaqMan-based real-time PCR assay, 91 samples, collected from symptomatic dogs originating from various cities between 2011 and 2015, were diagnosed. Positive specimens were characterised by means of minor groove binder (MGB) probe PCR. The results showed that all samples but one (98.9%) were CPV positive, of which 1 (1.1%) was characterised as CPV-2a, 43 (47.7%) as CPV-2b and 39 (43.3%) as CPV-2c. Interestingly, a co-infection with CPV-2b and CPV-2c was detected in 4 (4.4%) samples and 3 (3.3%) samples were not characterised. Sequencing of the full VP2 gene revealed these 3 uncharacterised strains as CPV-2c, displaying a change G4068A responsible for the replacement of aspartic acid with asparagine at residue 427, impacting the MGB probe binding. In this work we provide a better understanding of the current status of prevailing CPV strains in northern Africa.

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.

Vesiviruses have been detected in several animal species and as accidental contaminants of cells. We detected vesiviruses in asymptomatic kennel dogs (64.8%) and symptomatic (1.1%) and asymptomatic (3.5%) household dogs in Italy. The full-length genome of 1 strain, Bari/212/07/ITA, shared 89%–90% nt identity with vesiviruses previously detected in contaminated cells.

Highlights • Dogs were administered type 2 or 2b modified-live canine parvovirus (CPV) vaccines. • Vaccine CPV-2b shedding occurred for a shorter period but with greater viral loads. • Viremia was detected for a longer period and at higher titers for CPV-2b than CPV-2. • CPV seroconvertion occurred earlier with CPV-2b than with CPV-2 vaccines. • Vaccine viruses were detected by PCR but not by antigen testing or hemagglutination., Canine parvovirus (CPV) modified live virus vaccines are able to infect vaccinated dogs replicating in the bloodstream and enteric mucosa. However, the exact duration and extent of CPV vaccine-induced viremia and fecal shedding are not known. With the aim to fill this gap, 26 dogs were administered two commercial vaccines containing a CPV-2 or CPV-2b strain and monitored for 28 days after vaccination. By using real-time PCR, vaccine-induced viremia and shedding were found to be long lasting for both vaccinal strains. Vaccinal CPV-2b shedding was detected for a shorter period than CPV-2 (12 against 19 mean days) but with greater viral loads, whereas viremia occurred for a longer period (22 against 19 mean days) and with higher titers for CPV-2b. Seroconversion appeared as early as 7 and 14 days post-vaccination for CPV-2b and CPV-2 vaccines, respectively. With no vaccine there was any diagnostic interference using in-clinic or hemagglutination test, since positive results were obtained only by fecal real-time PCR testing. The present study adds new insights into the CPV vaccine persistence in the organism and possible interference with diagnostic tests.

Unlike the original canine parvovirus type 2 (CPV-2), CPV-2 variants have gained the ability to replicate in vivo in cats but there is limited information on the disease patterns induced by these variants in the feline host. During 2008, two distinct cases of parvoviral infection were diagnosed in our laboratories. A CPV-2a variant was identified in a 3-month-old Persian kitten displaying clinical sign of feline panleukopenia (FPL) (acute gastroenteritis and marked leukopenia) and oral ulcerations, that died eight days after the onset of the disease. Two pups living in the same pet shop as the cat were found to shed a CPV-2a strain genetically identical to the feline virus and were likely the source of infection. Also, non-fatal infection by a CPV-2c strain occurred in a 2.5-month-old European shorthair kitten displaying non-haemorrhagic diarrhoea and normal white blood cell counts. By sequence analysis of the major capsid protein (VP2) gene, the feline CPV-2c strain showed 100% identity to a recent canine type-2c isolate. Both kittens had been administered multivalent vaccines against common feline pathogens including FPL virus. Whether and to which extent the FPL vaccines can protect cats adequately from the antigenic variants of CPV-2 should be assessed.

The sequence of the full-length gene encoding for the main capsid protein VP2 of 58 canine parvovirus (CPV) type 2c strains, along with recent CPV-2a/2b strains, was determined and analysed in comparison with reference CPV isolates. The CPV-2c strains displayed a low genetic variability and shared amino acid changes already detected in recent CPV-2a/2b isolates, with a phylogenetic clustering accounting for their geographical distribution. Analysis of the selection pressure driving CPV evolution confirmed that the VP2 gene is under purifying selection. The emergence and global spread of the new CPV variant provides an interesting model to better understand virus evolution.

A TaqMan real-time RT-PCR assay was developed for detection of RNA transcripts produced by replicating CPV-2. A pair of primers and a TaqMan probe targeting the spliced NS2 mRNA were designed. A synthetic DNA fragment was constructed to mimic the spliced NS2 mRNA by PCR-based gene assembly and was used for generation of standard RNAs. The detection limit of the assay was 1 × 10 2 RNA copies and standard curve displayed a linear range from 1 × 10 2 to 1 × 10 9 copies and a good reproducibility. The assay was then applied to determine the mRNA loads in the tissues of dogs naturally infected by CPV-2. mRNA was detected in a variety of tissues, including the central nervous system.

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 3 kb 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., Highlights • Sapoviruses (SaVs), Caliciviridae family, have been recently discovered in dogs. • Canine SaVs were detected in 2.2% of diarrheic dogs but not in asymptomatic dogs. • The viruses were genetically related to canine SaV prototypes detected in USA.

A minor groove binder (MGB) probe assay was developed to discriminate between type 2-based vaccines and field strains of canine parvovirus (CPV). Considering that most of the CPV vaccines contain the old type 2, no longer circulating in canine population, two MGB probes specific for CPV-2 and the antigenic variants (types 2a, 2b and 2c), respectively, were labeled with different fluorophores. The MGB probe assay was able to discriminate correctly between the old type and the variants, with a detection limit of 10(1) DNA copies and a good reproducibility. Quantitation of the viral DNA loads was accurate, as demonstrated by comparing the CPV DNA titres to those calculated by means of the TaqMan assay recognising all CPV types. This assay will ensure resolution of most diagnostic problems in dogs showing CPV disease shortly after CPV vaccination, although it does not discriminate between field strains and type 2b-based vaccines, recently licensed to market in some countries.

By antigenic and genetic characterization of canine parvovirus type 2 (CPV-2) strains collected in 2001 and 2002 in Italy, it was possible to observe the spread of viruses with an unusual mutation, Glu-426, affecting a major antigenic epitope of CPV-2. Out of 67 strains analyzed, 49 (73.13%) were characterized as CPV-2a, 6 (8.95%) were characterized as CPV-2b, and 12 (17.91%) were characterized as the Glu-426 mutant.

The genes encoding the glycoprotein VP7, the VP8* trypsin-cleavage product of the protein VP4, a fragment of the protein VP6 associated with subgroup (SG) specificity, and the enterotoxin NSP4 of rotavirus strains identified in diarrheic fecal samples of rabbits in Italy were sequenced. The Italian lapine rotavirus (LRV) strains possessed a G3 VP7, SG I VP6, and KUN-like NSP4, a gene constellation typical of LRVs. One LRV strain (30/96), isolated in 1996, shared the closest amino acid (aa) identity (87–96%) with the P[14] genotype, composed of human and LRV strains. Conversely, three LRV strains (160/01, 229/01, and 308/01), identified in 2001, were highly identical (90–95%) among each other, but showed low aa identity (34–77%) to the VP8* genotype-specific sequences of representative rotavirus strains of all remaining P genotypes. This report confirms the worldwide genetic constellations of LRVs and identifies a novel VP4 genotype in rabbits, tentatively proposed as genotype P[22].

An epidemiological survey for Canine parvovirus 2 (CPV-2) and Canine coronavirus (CCoV) was conducted in Albania. A total of 57 fecal samples were collected from diarrheic dogs in the District of Tirana during 2011–2013. The molecular assays detected 53 and 31 CPV- and CCoV-positive specimens, respectively, with mixed CPV–CCoV infections diagnosed in 28 dogs. The most frequently detected CPV type was 2a, whereas IIa was the predominant CCoV subtype. A better comprehension of the CPV–CCoV epidemiology in eastern European countries will help to assess the most appropriate vaccination strategies to prevent disease due to infections with these widespread agents of acute gastroenteritis in the dog.

Dog circovirus (DogCV) was identified in an outbreak of enteritis in pups in Italy. The disease was observed in 6 young dachshunds pups of a litter from a breeding kennel and caused the death of 2 dogs. Upon full-genome analysis, the virus detected in one of the dead pups (strain Bari/411–13) was closely related to DogCVs that have been recently isolated in the USA. The present study, if corroborated by further reports, could represent a useful contribution to the knowledge of the pathogenic potential of DogCV and its association with enteritis in dogs.

Diagnosis of canine parvovirus (CPV) infection is usually carried out by means of rapid immunochromatographic assays, but the ability of these tests to detect all CPV variants, including the recently identified CPV-2c, is still debated. To determine if the assays detect the different CPV variants, 201 CPV PCR-positive faecal samples or rectal swabs were tested using a commercially available in-house test. Specimens (CPV-2a, n=51; CPV-2b, n=50; CPV-2c, n=100), containing CPV DNA loads >10(5) DNA copies/mg faeces, as determined by real-time PCR, were selected from previous studies. The percentage of positive in-house tests was 80.4%, 78.0% and 77.0% for CPV types 2a, 2b and 2c, respectively, confirming the ability of the test to detect the new variant CPV-2c. However, considering the sensitivity limits of the in-house tests that have been observed previously, negative results from the in-house test kit should be confirmed by PCR-based methods.

We identified a novel calicivirus in a pup with enteritis. The isolate was related genetically (90.1% aa identity in the capsid protein) to a lion norovirus strain.

Bertolotti, Luigi et al., Live attenuated vaccines provide the most consistent protective immunity in experimental models of lentivirus infections. In this study we tested the hypothesis that animals infected with a naturally attenuated small ruminant lentivirus field strain of genotype E may control a challenge infection with a virulent strain of the caprine arthritis encephalitis virus (CAEV-CO). Within genotype E, Roccaverano strain has been described as attenuated since decreased arthritic pathological indexes were recorded in Roccaverano-infected animals compared to animals of the same breed infected with genotype B strains. Moreover, under natural conditions, animals double-infected with genotypes B and E appear less prone to develop SRLV-related disease, leading to a putative protective role of Roccaverano strain. Here we present evidence that goats experimentally infected with the avirulent genotype E SRLV-Roccaverano strain control the proviral load of a pathogenic challenge virus (CAEV-CO strain) more efficiently than naïve animals and appear to limit the spread of histological lesions to the contralateral joints. © 2012 Elsevier B.V., This work was funded by the Italian Ministry of Instruction, University and Research PRIN 2008 and Piedmont Region “Ricerca Sanitaria Finalizzata” 2008; and from projects from CICYT (no. AGL2010-22341-C04-01) and the Government of Navarra (no. IIQ14064.RI1).

The authors report CapHV.1 reactivation in two latently infected adult goats treated with dexamethasone (DMS) (4.40 mg/kg BW) for 6 days. Virus was reisolated from vaginal swabs from the 3rd to the 12th day post-treatment with DMS and from nasal swabs for 2 days (6th and 7th day post-treatment). The animals also showed an increase of neutralizing antibody (SN) titer to CapHV.1 3 weeks after the end of treatment with DMS.

The modified live canine parvovirus (CPV) vaccine was used to vaccinate intranasally twenty-five pups with maternal antibody. The vaccine was able to overcome the interference of maternal immunity in rates of 100%, 72.7% and 17.6% in pups with haemagglutination inhibition antibody titre of 40, 80 and 160 respectively.

Cats in the primary stage of Feline Immunodeficiency Virus (FIV) infection and FIV seronegative cats were vaccinated with a modified live Feline Panleukopenia virus vaccine (FPV-MLV). The FPV-MLV strain was not pathogenic for FIV seronegative cats, whereas in FIV infected cats it produced severe clinical signs, similar to those typically observed in cats naturally infected with field strains of FPV (fever, diarrhoea, leukopenia).

An epidemiological survey for canine parvovirus (CPV) and canine coronavirus (CCoV) infections was conducted in Western Europe. A total of 156 faecal samples were collected from dogs with diarrhoea in Spain (n = 47), Italy (n = 39), France (n = 26), Germany (n = 21), the United Kingdom (n = 8), Belgium (n = 10), and the Netherlands (n = 5). Using molecular assays for virus detection and characterisation, CPV and CCoV were found to be widespread in European dog populations, either alone or in mixed infections. In agreement with previous reports, the original type CPV-2 was shown not to circulate in European dogs. The recently identified virus variant CPV-2c was predominant in Italy and Germany and present at high rates in Spain and France but was not detected in the UK or Belgium. Except for the UK, CCoV genotype I was identified in all European countries involved in the survey, albeit at a lower prevalence rates than CCoV genotype II.

Whether animals may act as reservoirs for human caliciviruses is unclear. By sequence analysis of a short fragment of the RNA-dependent RNA polymerase (RdRp) region, porcine sapovirus (SaV) strains that genetically resemble human SaVs have been detected in piglets, but more-informative sequences (capsid gene) were not available for a precise characterization. In this study, the 3′ terminus (the 3′ end of open reading frame 1 [ORF1], including the polymerase complex and the complete capsid; ORF2; and the 3′ untranslated region) of one such human SaV-like strain, 43/06-18p3/2006/It, was determined, revealing that these viruses are more related genetically to human (47.4 to 54.9% amino acid identity) than to animal (35.2 to 44.7% amino acid identity) SaVs in the capsid gene. In addition, the recombination-prone RdRp-capsid junction region was highly conserved with those of human SaVs of genogroup GI. The presence of porcine viruses similar to human SaVs is a significant finding because of the potential for zoonotic infections or generation of porcine/human recombinants.

The antigenic relationships among the original canine parvovirus type 2 (CPV-2) and the variants CPV-2a, -2b, and -2c were evaluated. Cross-antigenic evaluation revealed clear differences among the CPV variants, which were more appreciable by serum neutralization (SN) than by hemagglutination inhibition. Antigenic differences were found mostly between the original CPV-2 and the variants, but they were also observed among the variants CPV-2a, -2b, and -2c. The variant CPV-2c exhibited a unique antigenic pattern, since it was poorly recognized by the sera of animals immunized with CPV-2, CPV-2a, and CPV-2b. However, animals immunized with CPV-2c exhibited higher SN titers to CPV-2b than to the homologous virus CPV-2c. The observed antigenic differences might drive selection of CPV strains by generating differential immune pressure in the canine population, which raises concerns about vaccine efficacy.

Taking into account reports of the isolation of canine parvoviruses (CPVs) from faecal samples of cats, we developed a real-time PCR assay, based on minor groove binder (MGB) probe technology, for rapid discrimination between true feline panleukopenia viruses (FPLVs) from CPVs. The assay takes advantage of a single nucleotide polymorphism at position 3753 of the viral genome (corresponding to residue 323 of the capsid VP2 protein) and of the ability of MGB probes to bind specifically only to perfectly complementary sequences. The FPV/CPV assay was proven to be highly specific, sensitive and reproducible and correlated well with a TaqMan assay able to recognise canine as well as feline parvoviruses. Using this assay for extensive molecular surveys will provide precise information on the real circulation of the CPV antigenic variants, including the new variant 2c, in cat population worldwide.

The VP4 gene of a G5 Italian porcine rotavirus strain, 344/04-1, was nontypeable by PCR genotyping. The amino acid sequence of the full-length VP4 protein had low identity (≤76.6%) with the homologous sequences of representative strains of the remaining P genotypes, providing evidence for a novel P genotype.

The ability of a modified live canine parvovirus type 2b vaccine to elicit active immunization in pups with maternally derived antibodies (MDA) by intranasal administration was evaluated. The vaccine induced seroconversion in 100% of pups with MDA titers of ≤80 and in 51.6% of pups with titers between 160 and 320.

Rotavirus genome segment 4, encoding the spike outer capsid VP4 protein, of a porcine rotavirus (PoRV) strain, 134/04-15, identified in Italy was sequenced, and the predicted amino acid (aa) sequence was compared to those of all known VP4 (P) genotypes. The aa sequence of the full-length VP4 protein of the PoRV strain 134/04-15 showed aa identity values ranging from 59.7% (bovine strain KK3, P8[11]) to 86.09% (porcine strain A46, P[13]) with those of the remaining 25 P genotypes. Moreover, aa sequence analysis of the corresponding VP8* trypsin cleavage fragment revealed that the PoRV strain 134/04-15 shared low identity, ranging from 37.52% (bovine strain 993/83, P[17]) to 73.6% (porcine strain MDR-13, P[13]), with those of the remaining 25 P genotypes. Phylogenetic relationships showed that the VP4 of the PoRV strain 134/04-15 shares a common evolutionary origin with porcine P[13] and lapine P[22] rotavirus strains. Additional sequence analyses of the VP7, VP6, and NSP4 genes of the PoRV strain 134/04-15 revealed the highest VP7 aa identity (95.9%) to G5 porcine strains, a porcine-like VP6 within VP6 genogroup I, and a Wa-like (genotype B) NSP4, respectively. Altogether, these results indicate that the PoRV strain 134/04-15 should be considered as prototype of a new VP4 genotype, P[26], and provide further evidence for the vast genetic and antigenic diversity of group A rotaviruses.

Five laboratory tests for diagnosis of canine parvovirus type 2 (CPV-2) infection were employed to test 89 faecal samples collected from dogs with diarrhoea. The tests analysed were immunochromatography (IC), haemagglutination (HA), virus isolation (VI), conventional and real-time PCR. IC, HA, VI and conventional or real-time PCR were able, respectively, to detect CPV-2 antigen or nucleic acid in 41, 50, 54, 68 and 73 of the samples. The best correlation was found between conventional and real-time PCR, with an overall agreement of 94.38%. Sixty-eight samples that tested positive by HA, VI or conventional PCR were subjected to antigenic and/or genetic analyses of the CPV-2 strains by monoclonal antibody (MAb), restriction fragment-length polymorphism (RFLP) and/or sequence analyses. In sum, out of the 68 strains analysed, 26 were characterised as CPV-2a, 18 as CPV-2b and 24 as a CPV-2 Glu-426 mutant recently identified in Italy.

We report the detection and molecular characterization of a rotavirus strain, 10733, isolated from the feces of a buffalo calf affected with diarrhea in Italy. Strain 10733 was classified as a P[3] rotavirus, as the VP8* trypsin cleavage product of the VP4 protein revealed a high amino acid identity (96.2%) with that of rhesus rotavirus strain RRV (P5B[3]), used as the recipient virus in the human-simian reassortant vaccine. Analysis of the VP7 gene product revealed that strain 10733 possessed G6 serotype specificity, a type common in ruminants, with an amino acid identity to G6 rotavirus strains ranging from 88 to 98%, to Venezuelan bovine strain BRV033, and Hungarian human strain Hun4. Phylogenetic analysis based on the VP7 gene of G6 rotaviruses identified at least four lineages and an apparent linkage between each lineage and the VP4 specificity, suggesting the occurrence of repeated interspecies transmissions and genetic reassortment events between ruminant and human rotaviruses. Moreover, strain 10733 displayed a bovine-like NSP4 and NSP5/6 and a subgroup I VP6 specificity, as well as a long electropherotype pattern. The detection of the rare P[3] genotype in ruminants provides additional evidence for the wide genetic and antigenic diversity of group A rotaviruses.

The sequence of the S gene of a field canine coronavirus (CCoV), strain Elmo/02, revealed low nucleotide (61%) and amino acid (54%) identity to reference CCoV strains. The highest correlation (77% nt and 81.7% aa) was found with feline coronavirus type I. A PCR assay for the S gene of strain Elmo/02 detected analogous CCoVs of different geographic origin, all which exhibited at least 92-96% nucleotide identity to each other and to strain Elmo/02. The evident genetic divergence between the reference CCoV strains and the newly identified Elmo/02-like CCoVs strongly suggests that a novel genotype of CCoV is widespread in the dog population.

Canine parvovirus type 2 (CPV2) emerged in 1978 as causative agent of a new disease of dogs. New antigenic variants (biotypes), designated CPV2a and CPV2b, became widespread during 1979 to 1980 and 1984, respectively. At the present time the original CPV2 has disappeared in the dog population and has been replaced by the two new viruses. In the present study the comparison of neutralizing antibody titers in two groups of pups (18 pups in each group) inoculated with CPV2 and CPV2b modified live virus vaccines is reported. Using the hemagglutination inhibition (HI) test, relevant differences between antibody titers, against either the homologous or the heterologous virus, were not constantly observed. Using the neutralization (Nt) test, however, the pups inoculated with CPV2 had antibody titers which were approximately 30 times higher to the homologous virus (mean, 4,732) than to the heterologous virus (CPV2b) (mean, 162). The results of these experiments support two conclusions: (i) the HI test may not always accurately evaluate the true immune status of dogs with respect to CPV, and (ii) dogs inoculated with CPV2 vaccine develop relatively low Nt antibody titers against the heterologous virus (CPV2b). These data may suggest an advantage for new vaccines, considering that most presently licensed vaccines are produced with CPV2, which no longer exists in the dog population.

The results of vaccination trials carried out on pups with maternally derived antibodies (MDA) to canine parvovirus (CPV), using a modified-live CPV-2b variant vaccine (29-97/40 strain), are reported. The vaccine was able to overcome the obstacle of MDA, and to elicit protective immunity in 100% of the pups whose antibody titres were 1:10-1:40, 83% of the pups with titres of 1:80, 57% of the pups with titres of 1:160, and even in 60% of the pups with antibody titres of 1:320.

Porcine rotavirus strains (PoRVs) bearing human-like VP4 P[6] gene alleles were identified. Genetic characterization with either PCR genotyping or sequence analysis allowed to determine the VP7 specificity of the PoRVs as G3, G4, G5 and G9, and the VP6 as genogroup I, that is predictive of a subgroup I specificity. Sequence analysis of the VP8* trypsin-cleavage product of VP4 allowed PoRVs to be characterized further into genetic lineages within the P[6] genotype. Unexpectedly, the strains displayed significantly higher similarity (up to 94.6% and 92.5% at aa and nt level, respectively) to human M37-like P[6] strains (lineage I), serologically classifiable as P2A, or to the atypical Hungarian P[6] human strains (HRVs), designated as lineage V (up to 97.0% aa and 96.1% nt), than to the porcine P[6] strain Gottfried, lineage II (

Two isolates of canine parvovirus (CPV) were obtained from dogs affected with severe haemorrhagic diarrhoea. Type 2b antigenic specificity was predicted by both antigenic analysis with monoclonal antibodies and PCR characterization with type-specific primers. Nevertheless, sequence analysis of the capsid protein-encoding gene revealed two amino acid changes. One of the changes affected position 426 (Asp to Glu), in a major antigenic site of the viral capsid, determining the replacement of a residue unique to CPV type 2b. The failure of established typing methods to distinguish this antigenic variant was overcome by the development of an RFLP assay.