Molecular and phylogenetic analysis of Vietnamese canine parvovirus 2C originated from dogs reveals a new Asia-IV clade.

Canine parvovirus type 2 (CPV-2) is a small, single-stranded DNA virus causing fatal haemorrhagic enteritis in dogs. Currently, CPV-2 is classified into CPV-2a, CPV-2b and CPV-2c based on genetic variation in the VP2 gene. The CPV-2c variant has become ubiquitous worldwide and gained attention for monitoring parvoviral evolution. In this study, we characterized the full-length genome sequences of CPV-2c strains obtained from 59 dogs in Vietnam. Molecular analysis revealed that Vietnamese CPV-2c shared a common evolutionary pattern with the Asian CPV-2 clade, which is marked by genetic signature patterns in the structural and nonstructural proteins. In addition, these Vietnamese CPV-2c strains exhibited unique Thr112Ile and Ile447Met mutations in the VP1 and VP2 sequence, respectively. Interestingly, phylogenetic analysis indicated that the mutations of amino acid residues in both the structural and nonstructural genes have contributed to the emergence of a new clade, designated here as the Asia-IV clade. The substitution rates, estimated from a dataset containing 199 sequences over the last 42 years, confirmed that CPV-2 showed a high rate of nucleotide substitution, at about 2.49 × 10-4 nucleotide substitutions per site per year (nt/s/y), with VP1/2 and NS1/2 estimates of 3.06 × 10-4 and 3.16 × 10-4 nt/s/y, respectively. Even though no evidence of genetic recombination in these Vietnamese CPV-2c strains was established, potential positive selection sites were observed in both the structural and nonstructural genes, suggesting the viral evolutionary process has occurred in both the structural and nonstructural proteins. Genetic and evolutionary analysis of the full-length genome sequence is necessary to gain evolutionary insight of CPV-2.

Genetic analysis and emergence of canine parvovirus type 2c in South Eastern Nigeria.

BACKGROUND: Genetic analysis of canine parvovirus type 2 (CPV-2) variants circulating in South Eastern Nigeria was investigated. The original strain of CPV-2 emerged in 1978, mutated later to CPV-2a and has continued to be evolved. AIMS: To genetically characterize CPV-2 strains detected in dogs in South Eastern Nigeria and to phylogenetically group the viruses with existing sequencing data. METHODS: A total number of 82 rectal swabs were collected and stored in virus transport medium (VTM) from suspected cases of CPV-2 within the study area and were tested with polymerase chain reaction (PCR). RESULTS: Seventy-nine samples (96.3%) were positive for CPV-2 and sequence analysis of partial VP2 gene of 20 amplicons revealed circulation of CPV-2a (n=4) and CPV-2c (n=16) in the region. The obtained strains clustered together. However, the group was further divided into two clear clusters comprising of 2a and 2c strains. The vaccine strain and the CPV-2 reference strains from USA formed a monophyletic cluster. CONCLUSION: Canine parvovirus types 2a and 2c are co-circulating in South Eastern region of Nigeria and therefore, there is an urgent need for an improved vaccine to cover for the emerging strain (CPV-2c) in Nigeria.

Genetic characterization of canine parvovirus type 2c from domestic dogs in Korea.

Canine parvovirus type 2 (CPV-2) is an aetiological agent that causes acute haemorrhagic enteritis and fatal myocarditis in dogs. Since CPV-2 first emerged in the late 1970s, its rapid evolution has resulted in three antigenic variants: CPV-2a, CPV-2b and CPV-2c. Here, we report, for the first time in Korea, two cases of CPV-2c infection in two dogs with severe diarrhoea. The complete open reading frame (4,269nt) of CPV-2, encoding both non-structural (NS) and structural (VP) proteins, was sequenced. Based on the amino acid Gln present at residue 426 of the VP2 gene, these strains were typed as CPV-2c, and were named Korea CPV-2c_1 and Korea CPV-2c_2. These strains shared 99.48% reciprocal nucleotide sequence identity and had the highest nucleotide identity (99.77%-99.34%) with Asian CPV strains isolated in China, Italy (found in a dog imported from Thailand), and Vietnam from 2013 to 2017. Phylogenetic analysis based on the non-structural (NS1) and capsid (VP2) genes revealed that Korean CPV-2c strains clustered closely to Asian CPV strains, and separately from strains isolated in Europe, South America and North America. Amino acid changes never reported before were observed in NS1 (Thr70Pro, Cys287Tyr), VP1 (Lys17Arg, Phe33Leu) and VP2 (Gln365His, Ala516Val). Additional observed mutations, including Phe267Tyr, Tyr324Ile and Gln370Arg, have been previously reported in the recent CPV-2c strains with Asian origins. These results suggest that the Korean CPV-2c strains were potentially introduced via neighbouring Asian countries.

Epidemiological, clinical and pathological features of canine parvovirus 2c infection in dogs from southern Brazil / Aspectos epidemiológicos, clínicos e patológicos da infecção pelo parvovirus canino 2c em cães do Sul do Brasil

Canine parvovirus type 2c (CPV-2c) emerged in Europe in the early 2000's and rapidly spread out worldwide. Clinical and molecular data have demonstrated its circulation in Brazilian dogs, yet detailed descriptions of cases are still lacking. This article describes the epidemiological, clinical and pathological features of 24 cases of CPV-2c-associated disease in dogs submitted to veterinary clinics and laboratory diagnosis in southern Brazil (2014-2016). Most affected dogs presented signs/lesions suggestive of parvovirus enteritis: diarrhea, vomiting, hyperemia and hemorrhage of the serous membrane of the small intestine, diffuse segmental granulation, atrophy of the villi, necrosis and fusion of crypts, squamous metaplasia and epithelial syncytia. A number of cases presented features divergent from the classical presentations, including a wide variation in the color of feces (reddish and/or yellowish, light-brownish, orange-brown and brownish), involvement of adults (4/24) and vaccinated dogs (12/24), extensive involvement of the small intestine (8/20) and the presence of pulmonary edema (7/24) and convulsions (3/24). Feces and intestinal fragments submitted to PCR for the CPV-2 VP2 gene and to virus isolation in cell culture yielded positive results in 100% and 58.3% (14/24) of the cases, respectively. Nucleotide sequencing revealed a high nucleotide identity in VP2 (99.4 to 100%) and a consistent mutation at amino acid 426 (asparagine to glutamic acid), considered a signature of CPV-2c. These results confirm the involvement of CPV-2c in the described cases and demonstrate the importance of CPV-2c infection among Brazilian dogs, calling attention of veterinarians to correctly diagnose the disease, mainly considering the frequent atypical presentations.(AU)

O parvovírus canino tipo 2c (CPV-2c) surgiu na Europa no início do ano 2000 e rapidamente se espalhou pelas populações de cães ao redor do mundo. Dados clínicos e moleculares demonstraram a sua circulação em cães brasileiros, porém descrições detalhadas desses casos ainda são escassas. Este artigo descreve os aspectos epidemiológicos, clínicos e patológicos de 24 casos de doença gastroentérica associada com a infecção pelo CPV-2c em cães atendidos em clínicas veterinárias e submetidos ao diagnóstico laboratorial no Sul do Brasil (2014-2016). A maioria dos cães afetados apresentaram sinais e/ou lesões sugestivas de enterite por parvovírus: diarreia, vômitos, hiperemia e hemorragia na membrana serosa do intestino delgado, granulação segmentar difusa, atrofia das vilosidades, necrose e fusão de criptas, metaplasia escamosa e sincícios epiteliais. Alguns casos apresentaram características divergentes das apresentações clássicas, incluindo uma grande variação na cor das fezes (avermelhada e/ou amarelada, marrom-claro, marrom-alaranjada ou amarronzada), a participação dos adultos (4/24) e cães vacinados (12/24), um amplo envolvimento do intestino delgado (8/20), a presença de edema pulmonar (7/24) e convulsões (3/24). As fezes e fragmentos intestinais foram submetidos ao teste de PCR para o gene VP2 do CPV-2, e ao isolamento do vírus em cultura de células produziram resultados positivos em 100% e 58,3% (14/24) dos casos, respectivamente. O sequenciamento dos nucleótidos revelou uma alta identidade de nucleótidos na VP2 (99,4-100%) e uma mutação no aminoácido 426 (asparagina para ácido glutâmico), considerada uma assinatura de CPV-2c. Estes resultados confirmam o envolvimento do CPV-2c nos casos descritos e demonstra a importância da infecção pelo CPV-2c entre os cães do Brasil, chamando a atenção de veterinários para diagnosticar corretamente a doença, principalmente considerando-se as apresentações atípicas frequentes.(AU)

Phylodynamic and Genetic Diversity of Canine Parvovirus Type 2c in Taiwan.

Canine parvovirus type 2c (CPV-2c) emerged in 2000 and is known for causing a more severe disease than other CPV-2 variants in puppies. In 2015, the emerging CPV-2c variant was isolated in Taiwan and it subsequently became the predominant variant. To trace the evolution of Taiwanese CPV-2c, we compared complete VP2 genes of CPV-2c from Taiwan and sequences obtained from GenBank. The evolutionary rate of CPV-2c was estimated to be 4.586 × 10-4 substitutions per site per year (95% highest posterior density (HPD) was 3.284-6.076 × 10-4). The time to the most recent common ancestor (TMRCA) dated to 1990 (95% HPD: 1984-1996) and 2011 (95% HPD: 2010-2013) for the CPV-2c variant and Taiwanese isolates, respectively. The CPV-2c variant isolated from Taiwan was clustered with CPV-2c from China. This phylogenetic clade began to branch off in approximately 2010 (95% HPD was 3.823-6.497). Notably, two unique mutations of Taiwanese CPV-2c were found, Q383R and P410L. In summary, this is the first report on the genome evolution of CPV-2c in Taiwan, revealing that this CPV-2c variant shares a common evolutionary origin with strains from China. The demographic history inferred by the Bayesian skyline plot showed that the effective population of CPV-2c increased until 2006 and then slowly declined until 2011.

Detection of the Canine Parvovirus 2c Subtype in Australian Dogs.

Canine parvovirus (CPV-2) is an important cause of hemorrhagic enteritis in dogs. In Australia the disease has been associated with CPV-2a and CPV-2b variants. A third more recently emerged variant overseas, CPV-2c, has not been detected in surveys of the Australian dog population. In this study, we report three cases of canine parvoviral enteritis associated with CPV-2c infection; case 1 occurred in an 8-week-old puppy that died following acute hemorrhagic enteritis. Cases 2 and 3 were an 11-month-old female entire Saint Bernard and a 9-month-old male entire Siberian husky, respectively, both which had completed vaccination schedules and presented with vomiting or mild diarrhea only. Full genomic sequencing of parvoviral DNA from cases 1, 2, and 3 revealed greater than 99% homology to known CPV-2c variants and predicted protein sequences from the VP2 region of viral DNA from all three cases identified; glutamic acid residues at the 426 amino acid residue, characteristic of the CPV-2c variant. Veterinary professionals should be aware that CPV-2c is now present in Australia, detected in a puppy and vaccinated young adult dogs in this study. Further characterization of CPV-2c-associated disease and its prevalence in Australian dogs requires additional research.

Isolation and characterization of canine parvovirus type 2c (CPV-2c) from symptomatic puppies

Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.

Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies.

Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.