• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.361-366
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• 2014

The aim of this study was to determine if vaccines containing CPV-2 or CPV-2b provided protection against challenge with a recent Korean CPV-2a isolate. Twenty mongrel pups aged 9 weeks old were used. The commercial CPV-2 or CPV-2b vaccines were administered to each of the 8 pups thrice every 3 weeks, respectively. Two weeks after the last vaccination, all pups were challenged with CPV-2a (VR00174 strain) $1{\times}10^6\;TCID_{50}$. Clinical signs, fecal excretion of challenged CPV, and serological response of pups were observed for 2 weeks after challenge. All vaccinated pups did not display any clinical signs of disease after challenge with Korean CPV-2a isolate, whereas all non-vaccinated pups exhibited mucoid or hemorrhagic diarrhea, vomiting and anorexia. In all non-vaccinated pups, the virus could be detected in feces from 4 days after challenge, whereas in vaccinated pups, no evidence of viral excretion could be detected. Two of 4 non-vaccinated pups died 6 days after the challenge. This study showed that the two commercial CPV-2 and CPV-2b vaccines were effective in preventing infection and/or disease caused by the Korean CPV-2a isolate.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.243-248
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• 2009

After the original identification of canine parvovirus (CPV) type 2 (CPV-2) in 1978, new antigenic variants such as CPV-2a, CPV-2b and CPV-2c have become widespread in the most countries. In this study, the genetic analysis of canine parvovirus was investigated in a total of 13 CPV vaccines, which have been licensed in Korea since late 1980s, and a field isolate of CPV from a dog with CPV infection clinical symptom. The partial VP2 gene of CPV was amplified and sequenced from 13 vaccine strains and one field isolate. The results showed that of the 13 vaccine strains, 10 strains belong to the CPV-2, 2 strains to CPV-2b, the remaining and one isolate to CPV-2a type, respectively. Several mutations of amino acids were detected at residues of the critical region of the commercial vaccine strains. These data suggest that new type of vaccines containing CPV-2a or CPV-2b/2c type may be required for the better prevention of new CPV infection in dog population in Korea, because CPV-2 contained in most licensed vaccines has been replaced by antigenic variants designated CPV-2a or CPV-2b/c in the worldwide dog population.

• Korean Journal of Veterinary Research
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• v.55 no.3
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• pp.163-167
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• 2015

Canine parvovirus (CPV) is a major diarrhea-causing agent in puppies. Since CPV type 2 (CPV-2) emerged in 1978, new antigenic variants including CPV-2a, CPV-2b, and CPV-2c have been identified in many countries. Two puppies died suddenly at a veterinary clinic in Gyeonggi province, South Korea. Two viruses were isolated in A72 cells, confirmed as CPV strains based on a CPV rapid kit and an indirect fluorescence test and designated QIACP1403 and QIACP1404. The nucleotide sequences of complete VP2 genes of QIACP1403 and QIACP1404 were determined, and the corresponding amino acid sequences were deduced. Molecular analyses revealed that the QIACP1403 and QIACP1404 isolates were type CPV-2b. Several mutated amino acids were detected on VP2 gene residues of the two isolates. Phylogenetic analyses showed that the two isolates were most closely related to strain CPV-BM11, which was isolated from Chinese dogs in 2011. Our results suggest that these isolates may be a candidate for a vaccine to prevent CPV infection in dogs after conducting passages of the isolates in an in vitro culture system.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.43.1-43.13
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• 2020

Background: Canine parvovirus (CPV) and feline panleukopenia (FPV) cause severe intestinal disease and leukopenia. Objectives: In Korea, there have been a few studies on Korean FPV and CPV-2 strains. We attempted to investigate several genetic properties of FPV and CPV-2. Methods: Several FPV and CPV sequences from around world were analyzed by Bayesian phylo-geographical analysis. Results: The parvoviruses strains were newly classified into FPV, CPV 2-I, CPV 2-II, and CPV 2-III genotypes. In the strains isolated in this study, Gigucheon, Rara and Jun belong to the FPV, while Rachi strain belong to CPV 2-III. With respect to CPV type 2, the new genotypes are inconsistent with the previous genotype classifications (CPV-2a, -2b, and -2c). The root of CPV-I strains were inferred to be originated from a USA strain, while the CPV-II and III were derived from Italy strains that originated in the USA. Based on VP2 protein analysis, CPV 2-I included CPV-2a-like isolates only, as differentiated by the change in residue S297A/N. Almost CPV-2a isolates were classified into CPV 2-III, and a large portion of CPV-2c isolates was classified into CPV 2-II. Two residue substitutions F267Y and Y324I of the VP2 protein were characterized in the isolates of CPV 2-III only. Conclusions: We provided an updated insight on FPV and CPV-2 genotypes by molecular-based and our findings demonstrate the genetic characterization according to the new genotypes.

• Korean Journal of Veterinary Research
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• v.63 no.2
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• pp.19.1-19.6
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• 2023

Rapid immunochromatography test (RICT) kits are commonly used for the diagnosis of canine parvovirus (CPV) because of their rapid turnaround time, simplicity, and ease of use. However, the potential for cross-reactivity and low sensitivity can yield false-positive or false-negative results. There are 4 genotypes of CPV. Therefore, evaluating the performance and reliability of RICT kits for CPV detection is essential to ensure accurate diagnosis for appropriate treatment. In this study, we evaluated the performance of commercial RICT kits in the diagnosis of all CPV genotypes. The cross-reactivity of 6 commercial RICT kits was evaluated using 8 dog-related viruses and 4 bacterial strains. The limit of detection (LOD) was measured for the 4 genotypes of CPV and feline panleukopenia virus. The tested kits showed no cross-reactivity with the 8 dog-related viruses or 4 bacteria. Most RICT kits showed strong positive results for CPV-2 variants (CPV-2a, CPV-2b, and CPV-2c). However, the 2 kits produced negative results for CPV-2 or CPV-2b at a titer of 10⁵ FAID₅₀/mL, which may result in inaccurate diagnoses. Therefore, some kits need to improve their LOD by increasing their binding efficiency to detect all CPV genotypes.

• Journal of Veterinary Science
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• v.25 no.4
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• pp.56.1-56.13
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• 2024

Importance: Canine parvovirus enteritis (CPE) is a contagious viral disease of dogs caused by the canine parvovirus-2 (CPV-2) associated with high morbidity and mortality rates. CPV-2 has a high global evolutionary rate. Molecular characterization of CPV-2 and understanding its epidemiology are essential for controlling CPV-2 infections. Objective: This study examined the risk factors and survival outcomes of dogs infected with CPV-2. Molecular characterization of CPV-2 genotypes circulating in Egypt was performed to determine the evolution of CPV-2 nationally and globally. Methods: An age-matched case-control study was conducted on 47 control and 47 CPV-infected dogs. Conditional logistic regression analysis examined the association between the potential risk factors and CPE in dogs. Survival analysis was performed to determine the survival pattern of the infected dogs. Thirteen fecal samples from infected dogs were collected to confirm the CPV genotype by CPV-2 VP2 gene sequencing, assembly of nucleotide sequences, and phylogenic analysis. Results: Unvaccinated and roamer dogs had eight and 2.3 times higher risks of CPV infection than vaccinated dogs and non-roamer dogs, respectively. The risk of death from CPE was high among dogs without routine visits to veterinary clinics and among non-roamer dogs. Molecular characterization of CPV-2 confirmed its genotype identity and relationship with the CPV-2 c and b clade types. Conclusions and Relevance: This study highlights the potential factors for CPE control, especially vaccination and preventing dogs from roaming freely outside houses. Isolated CPV genotypes are closely related to southern Asian genotypes, suggesting a substantial opportunity for global transmission.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1271-1279
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• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• Journal of Veterinary Science
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• v.23 no.1
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• pp.14.1-14.11
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• 2022

Background: Carnivore protoparvovirus 1, also known as canine parvovirus type 2 (CPV-2), is the main pathogen in hemorrhagic gastroenteritis in dogs, with a high mortality rate. Three subtypes (a, b, c) have been described based on VP2 residue 426, where 2a, 2b, and 2c have asparagine, aspartic acid, and glutamic acid, respectively. Objectives: This study examined the presence of CPV-2 variants in the fecal samples of dogs diagnosed with canine parvovirus in Bogotá. Methods: Fecal samples were collected from 54 puppies and young dogs (< 1 year) that tested positive for the CPV through rapid antigen test detection between 2014-2018. Molecular screening was developed for VP1 because primers 555 for VP2 do not amplify, it was necessary to design a primer set for VP2 amplification of 982 nt. All samples that were amplified were sequenced by Sanger. Phylogenetics and structural analysis was carried out, focusing on residue 426. Results: As a result 47 out of 54 samples tested positive for VP1 screening, and 34/47 samples tested positive for VP2 980 primers as subtype 2a (n = 30) or 2b (n = 4); subtype 2c was not detected. All VP2 sequences had the amino acid, T, at 440, and most Colombian sequences showed an S514A substitution, which in the structural modeling is located in an antigenic region, together with the 426 residue. Conclusions: The 2c variant was not detected, and these findings suggest that Colombian strains of CPV-2 might be under an antigenic drift.

• Journal of Veterinary Clinics
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• v.25 no.6
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• pp.435-439
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• 2008

We evaluated the patterns of serology and fecal viral shedding for any differences by hemagglutination inhibition (HI) and real-time PCR on Korean CPV-2 isolates (CPV-2a-I, CPV-2a-V and CPV-2b). We successfully detected fecal viral shedding from samples extracted 2-3 d.p.i., regardless of the onset of clinical signs. In addition, the pattern of viral shedding differed depending on the CPV-2 isolates used for inoculation. We also observed differences in the serological pattern that was also depended on the CPV-2 isolates inoculated. The onset and amount of fecal viral shedding were not correlated with the level of antibody titers in this study. Our study is a valuable resource for understanding the different pathobiology of the CPV-2 isolates and the correlation between the patterns of serum antibody titer and fecal viral shedding.

• BMB Reports
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• v.39 no.1
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• pp.16-21
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• 2006

The coat protein (CP) of Papaya ringspot virus (PRSV) was analyzed for presentation of the antigenic peptide of animal virus, Canine parvovirus (CPV), in Escherichia coli (E. coli). The 45 nucleotides fragment coding for the 15-aa peptide epitope of the CPV-VP2 protein was either inserted into the PRSV-cp gene at the 5', 3' ends, both 5' and 3' ends or substituted into the 3' end of the PRSV cp gene. Each of the chimeric PRSV cp genes was cloned into the pRSET B vector under the control of the T7 promoter and transformed into E. coli. The recombinant coat proteins expressed from different chimeric PRSV-cp genes were purified and intraperitoneally injected into mice. All of the recombinant coat proteins showed strong immunogenicity and stimulate mice immune response. The recombinant coat proteins containing the CPV epitope insertion at the C terminus and at both N and C termini elicited ten times higher specific antisera in immunized mice compared with the other two recombinant coat proteins which contain the CPV epitope insertion at the N terminus and substitution at the C terminus.