Molecular epidemiology of canine parvovirus in southern India

Occurrence of canine parvovirus type 2c in diarrhoeic faeces of dogs in Kolkata, India

Canine parvovirus-2(CPV-2) causes a highly contagious disease of dogs characterised by acute hemorrhagic gastroenteritis, lethargy, vomiting, fever and usually bloody or mucoid diarrhoea. In the present study, 41 faecal samples collected from dogs exhibiting the signs of fever, vomition, bloody or mucoid diarrhoea in Kolkata, India were screened by haemagglutination test and PCR for detection of capsid protein coding VP2 gene. The viral genotype was detected by multiplex PCR and analysis of partial VP2 gene nucleotide sequences of selected PCR products with bioinformatics tool. Thirteen (31.71%) samples were found positive with HA titre ≥ 32 whereas 28 (68.29%) samples were positive by PCR of VP2 gene indicating higher sensitivity of PCR. Highest occurrence of CPV-2 was observed in the age group of 1-6 months (80.65%) and non-descript breeds with no history of vaccination (85%). Three samples were antigenic type CPV-2a, rest were CPV-2b/CPV 2c. Six CPV sequences were found to be highly similar to published CPV 2c sequences in BLAST analysis revealing a maximum identity of 99-100% with other CPV-2c strains and clustered together with CPV-2c strains of India and other countries in phylogenetic analysis. The present study highlights the need for continuous monitoring of samples to detect gradual changes in circulating CPV-2 genotypes in India.

Phylodynamic and genetic diversity of parvoviruses of cats in southern India

Feline panleukopenia virus (FPV) and Canine parvovirus (CPV) infections are highly contagious diseases causing severe gastroenteritis with high fatality rates in cats. Realising the importance of cats as a potential source of genetic diversity for parvoviruses, the present study trace the evolutionary history and dynamics of parvovirus variants by characterizing the full-length viral polypeptide 2 (VP2) gene of parvovirus from domestic cats and cats from rescue shelters in Southern India. The study confirmed the presence of both CPV and FPV infections among the cat population. The full-length VP2 gene analysis of parvoviruses from cats; five had amino acid variations characteristic of FPV and one sequence was New CPV-2a/FPV. Three new mutations (hitherto not reported) were identified at 303rd, 441st and 554th amino acid positions. One potential recombination event was identified in VP2 sequence from a cat (New CPV-2a / FPV recombinant). The molecular analysis confirmed that cat populations are susceptible to CPV variants and FPV, thereby promoting superinfection and co-infection with multiple parvoviruses and potentially facilitating transmission, recombination and high genetic heterogeneity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-022-00760-4.

A novel one-step amplification refractory mutation system PCR (ARMS-PCR) for differentiation of canine parvovirus-2 variants

Enteritis caused by CPV-2 antigenic variants (CPV-2a, 2b, and 2c) is frequently reported in dogs worldwide leading to significant morbidity and mortality. Here, we describe about a simple, single-step, ARMS-PCR strategy targeting the mutant 426 amino acid of VP2 to differentiate CPV-2 antigenic types. A total of 150 fecal samples were subjected to ARMS-PCR of which 18 were typed as CPV-2a, 79 were typed as CPV-2b, and 6 were typed as CPV-2c. The ARMS-PCR results were validated by randomly sequencing partial VP2 gene of 14 samples. Phylogenetic analysis of partial VP2 gene sequencing of each of the CPV-2 variants revealed that CPV-2a and CPV-2b isolates formed a separate clade of Indian lineage, while CPV-2c shared common evolutionary origin with Asian lineage. The developed technique is first of its kind, one-step, rapid, sequencing independent method for typing of CPV-2 antigenic variants.

Prevalence and molecular characterization of canine parvovirus

Background and Aim:

Canine parvovirus (CPV) belonging to family Parvoviridae causes hemorrhagic gastroenteritis in dogs and heavy mortality in young dogs. The virus has three structural (VP1, VP2 and VP3) and two non-structural proteins (NS1 and NS2), VP2 being highly immunogenic. This study aims to study molecular epidemiology of CPV by sequence analysis of VP2 gene to determine the prevailing antigenic type(s) in the northern regions of India.

Materials and Methods:

A total of 118 rectal swabs collected from dogs exhibiting clinical signs of CPV infection were processed for the isolation of DNA and subjected to polymerase chain reaction (PCR) and nested PCR (NPCR). A total of 13 NPCR products selected randomly were subjected to sequence analysis of VP2 gene.

Results:

The percent positivity of CPV was found 28% and 70% by PCR and NPCR, respectively. Dogs with vaccination history against CPV too were found positive with a percent positivity of 24.10%. Gene sequencing and phylogenetic analysis of VP2 gene from these isolates revealed that most samples formed a clade with CPV-2a isolates.

Conclusion:

Sequence analysis and phylogenetic analysis of VP2 gene in the studied regions of northern India revealed that CPV-2a was the most prevalent antigenic type.

Molecular epidemiology of Canine parvovirus shows CPV-2a genotype circulating in dogs from western India

Canine parvovirus (CPV) has emerged as an acute pathogen of young canine causing haemorrhagic enteritis and myocarditis. It is widely distributed and underreported in India. Therefore the study was conducted to type the CPV circulating in western Maharashtra. The faecal samples (n = 150) from clinically ill dogs showing diarrhoea and vomition were collected and subjected to haemagglutination (HA) with porcine RBC's. The DNA was extracted from the samples showing HA titres above 64 and subjected for amplification of VP₂ gene fragment by PCR. The amplicons were subjected for restriction fragment length polymorphism (RFLP), sequencing and BEAST phylogenetic analysis. The results revealed 6% positivity by PCR. The RFLP results indicated single cleavage site for ApaLI and HinfI with an exception of two sites for HinfI. The nucleotide sequences showed nonfunctional nucleotide changes at different locations. The sequence analysis indicated that the nucleotide divergence within isolates under study was 0.00-0.42%, while the nucleotide homology was 99.58-100%. The most recent common ancestor was determined by molecular clock analysis using Bayesian methods. The sequence and phylogenetic analysis suggested the isolates as CPV-2a and KATN1 (KU866391, 2014) isolate from Tamilnadu, India as time to most recent common ancestor (TMRCA). The results revealed the circulating CPV in canines from western India as CPV2a genotype.

Molecular epidemiology of canine parvovirus type 2 in Vietnam from November 2016 to February 2018

BACKGROUND

Canine parvovirus type 2 (CPV-2) was first identified in the late 1970s; it causes intestinal hemorrhage with severe bloody diarrhea in kennels and dog shelters worldwide. Since its emergence, CPV-2 has been replaced with new genetic variants (CPV-2a, CPV-2b, and CPV-2c). Currently, information about the genotype prevalence of CPV-2 in Vietnam is limited. In the present study, we investigated the genotype prevalence and distribution of CPV-2 in the three regions of Vietnam.

METHODS

Rectal swabs were collected from 260 dogs with suspected CPV-2 infection from northern, central, and southern Vietnam from November 2016 to February 2018. All samples were identified as parvovirus positive by real-time PCR, and further genotyping was performed using a SimpleProbe® real-time PCR assay.

RESULTS

Of the 260 Vietnamese CPV-2 isolates, 6 isolates (2.31%) were identified as CPV-2a, 251 isolates (96.54%) were identified as CPV-2c and 3 isolates (1.15%) were untypable using the SimpleProbe® real-time PCR assay. In northern Vietnam, the percentages of CPV-2a and CPV-2c were 2.97% (3/101) and 97.3% (98/101), respectively. In central Vietnam, the percentages of CPV-2a and CPV-2c were 1.11% (1/90) and 98.89% (89/90), respectively. In southern Vietnam, the percentages of CPV-2a and CPV-2c were 3.03% (2/66) and 96.97% (64/66), respectively. CPV-2b was not observed in this study. The VP2 genes of CPV-2c in Vietnam are more genetically similar to those of CPV-2c strains in China and Taiwan than to those of prototype CPV-2c strains (FJ222821) or the first Vietnamese CPV-2c (AB120727).

CONCLUSION

The present study provides evidence that CPV-2c is the most prevalent variant in Vietnam. Phylogenetic analysis demonstrated that the recent Vietnamese CPV-2c isolates share a common evolutionary origin with Asian CPV-2c strains.

Diagnosis and characterization of canine parvovirus-2 affecting canines of South Gujarat, India

The present study was carried out in the region of South Gujarat, India, to determine the prevalence and predisposing factors of canine parvovirus-2 (CPV-2) infection in acute gastroenteritis of pups. Further, haemagglutination (HA) test, enzyme linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) and rapid immunochromatography test were compared for diagnosis and prevalent CPV-2 types were ascertained. A total of 73 diarrhoea samples were collected and out of those 32, 33 and 35 were found positive via HA, ELISA and PCR, respectively. In rapid test, 26/52 samples were found positive. Among different age-groups, 11/24 and 13/21 animals were positive in pups aged 4–8 and 8–12 weeks, respectively. All but one (34/35) positive samples were from unvaccinated animals. Labrador was found to be the most susceptible breed (n = 13) to infection. Considering PCR as the best test, 47.94% (35/73) prevalence of CPV was recorded. Among PCR positive samples, 3 and 32 belonged to type CPV-2a and CPV-2b, respectively. Type CPV-2c was not detected among the examined samples. Sequencing analysis of 9/10 CPV-2b isolates revealed single nucleotide polymorphism (SNP) (A-G) at position 4106 (alanine to threonine) and suggested the occurrence of mutant, new CPV-2b in this area. As other major pathogen canine coronavirus was detected in 7/38 CPV negative samples. Conclusively, CPV-2 infection was detected in 47.97% cases of AGE of pups which warrants search for other pathogens in the diagnostic procedure. This work is among the few recent reports which depict the occurrence of a novel mutant (new CPV-2b) in India.

Molecular characterisation of parvoviruses from domestic cats reveals emergence of newer variants in India

Objectives

The present study was undertaken to characterise the viral polypeptide 2 (VP2) gene of parvovirus from domestic cats in India.

Methods

The faecal samples from diarrhoeic/healthy domestic cats were collected from different geographical regions of India for screening by PCR assay followed by sequence analysis of the VP2 gene.

Results

Canine parvovirus (CPV)/feline panleukopenia virus (FPV) infections were found in 12 (11.3%) of 106 faecal samples tested. Two new CPV-2a (297Ala and Asn426) and three FPV strains were identified by VP2 gene analysis. Several unique and existing amino acid mutations were found, suggesting continuous evolution and emergence of newer variants. The phylogenetic analysis of the CPV sequences revealed that the two new CPV-2a strains from Mumbai (MC8) and Puducherry (P15) were clustered together in a single clade but had evolved independently and were ancestrally related to Chinese CPV-2a isolates. The FPV sequences (T-C-6 and T-C-1) from Thrissur, Kerala, formed a different clade (FPV clade) and were closely related to each other and had an ancestral relationship with an FPV isolate from the USA. Another FPV isolate from Goa (GC1) was positioned in the same clade but had evolved independently.

Conclusions and relevance

Detection of CPV in both diarrhoeic/healthy cats and the occurrence of FPV infection in a vaccinated cat provide new insights into parvovirus infections in cats in India.

Isolation of Canine parvovirus with a view to identify the prevalent serotype on the basis of partial sequence analysis

Aim:

The aim of this study was to isolate Canine parvovirus (CPV) from suspected dogs on madin darby canine kidney (MDCK) cell line and its confirmation by polymerase chain reaction (PCR) and nested PCR (NPCR). Further, VP2 gene of the CPV isolates was amplified and sequenced to determine prevailing antigenic type.

Materials and Methods:

A total of 60 rectal swabs were collected from dogs showing signs of gastroenteritis, processed and subjected to isolation in MDCK cell line. The samples showing cytopathic effects (CPE) were confirmed by PCR and NPCR. These samples were subjected to PCR for amplification of VP2 gene of CPV, sequenced and analyzed to study the prevailing antigenic types of CPV.

Results:

Out of the 60 samples subjected to isolation in MDCK cell line five samples showed CPE in the form of rounding of cells, clumping of cells and finally detachment of the cells. When these samples and the two commercially available vaccines were subjected to PCR for amplification of VP2 gene, a 1710 bp product was amplified. The sequence analysis revealed that the vaccines belonged to the CPV-2 type and the samples were of CPV-2b type.

Conclusion:

It can be concluded from the present study that out of a total of 60 samples 5 samples exhibited CPE as observed in MDCK cell line. Sequence analysis of the VP2 gene among the samples and vaccine strains revealed that samples belonged to CPV-2b type and vaccines belonging to CPV-2.

Epidemiological study of canine parvovirus infection in and around Bhubaneswar, Odisha, India

Aim:

An epidemiological study of canine parvovirus infection in dogs in and around Bhubaneswar, Odisha was conducted between December 2012 to March 2013 and prevalence rate was studied on the basis of age, breed, and sex.

Materials and Methods:

A total of 71 fecal samples from suspected diarrheic dogs were collected in sterile phosphate buffer saline (10% W/V) and examined by polymerase chain reaction (PCR) for detection of canine parvo virus infection, followed by epidemiological study in relation to age, breed, and sex.

Results:

Of 71 samples analyzed, 29 (40.85%) were found to be positive by PCR assay. The infection was higher in Deshi/local breeds (34.48%), followed by German shepherd (17.24%), equal incidences in mixed and Labrador retriever (10.34%), Rottweiler and German spitz showed 6.90% each and finally lower incidences in four breeds (3.45%) such as Dalmatians, Nea politan mastiff, Pug and Great Dane. Age-wise prevalence study revealed the infection being more in the age group of 3-6 months (41.37%), followed by equal incidences of 27.59% in 1-3 months and 6-12 months age group, and a low incidence in age groups above 12 months (3.45%). The incidence was predominantly higher in males (86.21%) than females (13.79%).

Conclusions:

The epidemiological analysis revealed that the breed wise prevalence was found to be more in Deshi breeds as compared to others, age groups below 6 months were found to be more prone to parvovirus infection and males were mostly infected.

Antigenic typing of canine parvovirus using differential PCR

Canine parvovirus (CPV) is an enteric pathogen causing hemorrhagic enteritis in pups of 3-6 months of age and is mainly transmitted via feco-oral route. In the present study, a total of 85 animals rectal swabs suspected of CPV were tested using a PCR, nested PCR and a newly designed differential PCR. Using PCR 7 (8.23 %) animals were positive whereas 39 (45.88 %) were positive by using nested PCR and 40 (47.05 %) were positive for either one or more than one antigenic types of CPV using differential PCR. Using differential PCR it was found that CPV-2a and CPV-2b were the most prevailing antigenic types. Also it was found that dogs that were vaccinated too yielded positive CPV indicating a possible presence of additional CPV antigenic types. Thus, the primers used in differential PCR can be used in a single PCR reaction to detect various antigenic types of CPV.