Molecular analysis of partial VP-2 gene amplified from rectal swab samples of diarrheic dogs in Pakistan confirms the circulation of canine parvovirus genetic variant CPV-2a and detects sequences of feline panleukopenia virus (FPV)

Investigation of canine parvovirus occurrence in cats with clinical signs of feline panleukopenia in Slovakia - pilot study

Introduction

Feline panleukopenia is a contagious viral disease caused by the feline panleukopenia virus (FPV). A closely related pathogen is canine parvovirus (CPV), and amino acid substitutions in this virus allow it to acquire a feline host range. In feline hosts, the disease induced by CPV manifests with similar symptoms to those caused by FPV or milder ones, leading to its underdiagnosis. The aim of this study was to determine the presence of CPV type 2 (CPV-2) in cats with clinical symptoms of panleukopenia and to assess the use of commercial CPV antigen tests for the clinical diagnosis of FPV.

Material and Methods

Samples from 59 cats from central Slovakia were included in the study. Rectal swabs were collected and clinically tested for parvovirus infection using a commercial antigen test. Antigen-positive samples were confirmed by PCR targeting the viral VP2 gene. The sequences of the PCR products were established with the Sanger method.

Results

Of 59 samples, 23 were revealed to be positive for parvovirus infection by both antigen and PCR test (38.9%). Analysis with the National Center for Biotechnology Information BLASTn application showed 99.78-100% pairwise identity with FPV. The mortality rate of parvovirus-infected cats included in this study was 8.69% (2/23).

Conclusion

Although feline disease with CPV-2 was not confirmed, the CPV antigen test was able to detect FPV infection.

Genetic characterization of parvoviruses identified in stray cats in Nigeria

Parvoviruses are a major cause of haemorrhagic gastroenteritis, leukopenia and high mortality in cats and dogs. In this study, the presence and genetic characteristics of parvoviruses circulating among cats in Nigeria are reported. Faecal samples of stray cats from live animal markets in southwestern (Oyo and Osun States) and north-central (Kwara State) Nigeria were screened for the presence of parvoviral DNA using a qPCR. Positive samples were further characterized using a qPCR based on minor groove binder probes. Overall, 85/102 (83.3 %) stray cats tested positive for feline panleukopenia virus (FPV) DNA and one cat was co-infected with canine parvovirus-2 type a. Sequence analysis of the complete capsid region of 15 Nigerian FPV strains revealed that they were up to 99.9 % similar to the American reference strain FPV-b at the nucleotide level, and three of them presented amino acid mutations in key capsid residues. This is the first report of identification and molecular characterization of FPV strains in cats in Nigeria. The high prevalence of the virus emphasizes the need for constant surveillance of the circulation of parvoviruses in Nigeria and underscores the need to deploy an effective vaccination strategy.

Genetic diversity and relatedness of feline parvovirus in Vietnam and its potential implications for canine-feline transmission

Feline panleukopenia, caused by feline parvovirus (FPV), has been studied worldwide, but there have been very few studies conducted in Vietnam. In this study, 19 rectal swab samples were collected from northern Vietnam in 2018-2019 and screened for the presence of FPV using PCR. Through sequence analysis of the full-length VP2 gene, it was found that the FPV strains detected in Vietnam were closely related to those obtained from dogs in Vietnam, Asia, Europe, and America. Moreover, the FPV strains found in Vietnam may constitute a distinct group, related to viruses sampled in China. Interestingly, most of the nucleotide changes identified were T-C substitutions.

Molecular characterization and genetic diversity of parvoviruses prevalent in cats in Central and Eastern China from 2018 to 2022

Cats are a potential source of genetic diversity for parvoviruses. Herein, 134 samples were collected from cats with clinical gastroenteritis and analyzed for the presence of viral DNA via polymerase chain reaction, which revealed 48 positive samples. Identity analysis of VP2 nucleotide sequences indicated that these 48 strains, belonging to feline panleukopenia virus (FPV) and canine parvovirus type-2 (CPV-2; including new CPV-2a and CPV-2c genotypes), shared 94.59-99.94% nucleotide identity with the reference strains. The FPV strain F8 (isolated from Vietnam) appeared to be a recombinant of strains HB2003 and JS1901, whereas the Chinese CPV-2b strain BM-(11) isolated in 2011 was believed to be a recombinant of strains AH2008 and JS1901. In phylogenetic tree analysis based on VP2 nucleotide sequences, all obtained FPV strains and most reference FPV strains were clustered together, except strain BJ-22, which originated from monkeys. Further, two new CPV-2a strains (AH2005 and AH2008) were close to the newly reported Chinese CPV-2a strains but were distant from the other CPV-2a strains, namely CPV-339 (from the United States) and K022 (from South Korea). Additionally, the FPV and CPV-2 strains had high mutation rates in the antigenic regions of the VP2 protein. According to model prediction of the CPV-VP2 protein, these mutations may cause changes in the tertiary structure of VP2. The findings of this study can be used to improve the pre-evaluation of vaccination efficacy against diseases caused by FPV and CPV-2 in domestic cats and understand their genotypic transmission and mutation trends.

Old and Novel Enteric Parvoviruses of Dogs

Parvovirus infections have been well known for around 100 years in domestic carnivores. However, the use of molecular assays and metagenomic approaches for virus discovery and characterization has led to the detection of novel parvovirus species and/or variants in dogs. Although some evidence suggests that these emerging canine parvoviruses may act as primary causative agents or as synergistic pathogens in the diseases of domestic carnivores, several aspects regarding epidemiology and virus-host interaction remain to be elucidated.

Metagenomic Analysis of DNA Viruses with Targeted Sequence Capture of Canine Lobular Orbital Adenomas and Normal Conjunctiva

Our study aims are: (1) to evaluate phenotypically normal canine conjunctival and orbital tissue and tissue from canine lobular orbital adenomas (CLOAs) for the presence of viral genomic material and (2) phylogenetically classify detected DNA viruses to determine if a DNA virus is associated with CLOAs. A total of 31 formalin fixed paraffin embedded CLOA tissue samples, 4 papillomas or sarcoid, and 10 fresh clinically normal conjunctival tissues were included in this study. Genomic DNA was isolated from all samples and sequencing libraries were prepared. The libraries were molecularly indexed and pooled and viral DNA was enriched via targeted sequence capture utilizing ViroCap. The libraries were sequenced on the Illumina HiSeq platform and compared to known viral DNA reference genomes to identify viral DNA. Carnivore parvovirus was identified in 6.4% and 20% of CLOA tissue and normal conjunctival samples, respectively. This study showed that conjunctival tissue from healthy dogs and CLOAs uncommonly harbor DNA viruses, and no DNA virus was associated with these tumors. Further studies are needed to evaluate the etiologic cause of CLOAs.

Phylogenetic analysis of canine parvovirus isolates from west Mediterranean region of Türkiye

Canine parvovirus type 2 (CPV-2) causes hemorrhagic enteritis, and is one of the most important and contagious pathogens of dogs. In this study, we aimed to determine the prevalence and antigenic variants of CPV enteritis in dogs. Fecal samples were collected from 35 dogs with mucoid to hemorrhagic diarrhea in the Western Mediterranean region of Türkiye between October 2019 and March 2021. DNA was isolated from the samples and examined using PCR analysis. Twenty-eight out of 35 dogs (80.00%) were detected to be positive for CPV. Of these, three had already been vaccinated. The partial VP2 genes of 15 CPV positive samples producing strong bands in agarose gels were sequenced. All strains were identified as CPV-2b, and the amino acid changes were identified. Discriminative amino acid changes were detected for different amino acid positions clearly defining new CPV-2b variants. Of the 15 isolates, three had previously unreported synonymous mutations. Phylogenetic analysis indicated that the strains obtained in this study were closely related to isolates from the Mersin province of Türkiye, except for three isolates that had synonymous mutations and were located in a separate branch from the other CPV-2b genetic variants previously detected in Mersin Province and Urfa Province in Türkiye. This study demonstrates the increase in the prevalence rates for CPV-2b circulating in vaccinated and nonvaccinated dogs. Taking into account the data from phylogenetic trees which highlights differences between the vaccine strains and the isolates, re-designing immunization strategies needs necessary.

Feline Panleukopenia Virus in Dogs from Italy and Egypt

Canine parvovirus and feline panleukopenia virus (FPV) are variants of Carnivore protoparvovirus 1. We identified and characterized FPV in dogs from Italy and Egypt using genomic sequencing and phylogenetic analyses. Cost-effective sequencing strategies should be used to monitor interspecies spread, evolution dynamics, and potential host jumping of FPV.

First molecular characterization and phylogenetic analysis of the VP2 gene of feline panleukopenia virus in Bangladesh

Feline panleukopenia virus (FPV) is a highly contagious infectious pathogen of cats globally. However, there is no information on the molecular identification and characterization of FPV in Bangladesh. Here, 8.16% (8/98) and 18.37% (18/98) of diarrheic cats tested positive for FPV by an immunochromatography (IC) test and PCR, respectively. The IC test showed 44.44% sensitivity and 100% specificity in comparison with PCR. Our newly sequenced Bangladeshi FPV strain (MN826076) showed the highest (99.71%) sequence identity to strains from the United Arab Emirates (UAE). Strain MN826076 contained two characteristic amino acid variations in VP2 identifying it as an FPV strain: valine at position 103 and aspartic acid at position 323. Phylogenetically, the VP2 of strain MN826076 was found to be closely related to 19 FPV strains, sharing the same clade.

Molecular Epidemiological Survey of Canine Parvovirus Circulating in China from 2014 to 2019

The global distribution of canine parvovirus (CPV-2) derived from a closely related carnivore parvovirus poses a considerable threat to the dog population. The virus is continuously undergoing genetic evolution, giving rise to several variants. To investigate the prevalence of Chinese CPV-2 strains in recent years, a total of 30 CPV-2 strains were collected from 2018 to 2021 and the VP2 gene was sequenced and analyzed. Two variants, new CPV-2a (297Ala, 426Asn) and CPV-2c (426Glu), were identified. In contrast to previous reports, the CPV-2c variant has gained an epidemiological advantage over the new CPV-2a variant in China. To compensate for the relatively small sample size, 683 Chinese CPV-2 strains identified between 2014 and 2019 were retrieved from the GenBank database and previous publications, and analyses of these strains further supported our findings, which should be considered since the CPV-2c variant has been frequently associated with immune failure in adult dogs. VP2 protein sequence analysis revealed several amino acid substitutions, including Ala5Gly, Pro13Ser, Phe267Tyr, Tyr324Ile, Gln370Arg, Thr440Ala, and Lys570Arg. Phylogenetic analysis of full-length VP2 gene indicated a close relationship between Chinese strains and other Asian strains, suggesting mutual transmission between Asian countries. Furthermore, intercontinental transmission is a cause for concern. Surprisingly, two feline panleukopenia virus (FPV) strains with the Ile101Thr mutation in the VP2 protein were identified in canine fecal samples; FPV has been considered incapable of infecting dogs. This study clarified the epidemic characteristics of Chinese CPV-2 strains detected between 2014 and 2019, offering a reference for epidemic control. In addition, the detection of FPV in canine samples may provide information for future studies on the evolution of carnivore parvoviruses.

Genetic characterization of feline panleukopenia virus from dogs in Vietnam reveals a unique Thr101 mutation in VP2

Background

Canine parvovirus type 2 (CPV-2) and feline parvovirus (FPV) are known as the main causes of several serious diseases and have a severe impact on puppies and kittens, respectively. FPV and new CPV-2 variants are all able to infect cats, causing diseases indistinguishable from feline panleukopenia. However, FPV only replicates efficiently in feline cells in vitro and replicates in dogs in the thymus and bone marrow without being shed in feces. In our previous study, the genotypes of six parvoviral isolates were unable to be identified using a SimpleProbe^® real-time PCR assay.

Methods

In the present study, we characterized previously unidentified FPV-like viruses isolated from dogs in Vietnam. The six isolates were utilized to complete VP2 gene sequencing and to conduct phylogenetic analyses.

Results

Sequence analysis of the six parvoviral strains identified the species as being similar to FPV. Phylogenetic analysis demonstrated that the complete VP2 genes of the strains are similar to those of FPV. The FPV-like strains contain a Thr101 mutation in the VP2 protein, which is different from prototype FPV strains.

Discussion

Our data provide evidence for the existence of changes in the charge, protein contact potential and molecular surface of the core of the receptor-binding size with an Ile101 to Thr101 mutation. This is also the first study to provide reliable evidence that FPV may be a threat to the Vietnamese dog population.

Surgically confirmed cases of cystic echinococcosis from Baluchistan Province, Pakistan for the years 2011-2018

INTRODUCTION

Cystic echinococcosis (CE) is a parasitic zoonotic disease caused by the larval stage of Echinococcus granulosus tapeworms. It has a worldwide geographic distribution and can threaten the livestock industry and human health in endemic areas, including Pakistan. CE prevalence is high in Pakistan due to lack of local knowledge about disease transmission and a lack of control measures. The Pakistan province of Baluchistan shares a border with Iran and Afghanistan and is largely agricultural. However, little is known about E. granulosus transmission in this region.

METHODS

Information on surgically confirmed cases of CE in Baluchistan Province was obtained through evaluation of paraffin fixed cyst samples and patient records obtained from three local hospitals for the years 2011-2018.

RESULTS

A total of 22 paraffin fixed samples were collected during the study period. The majority of cysts were obtained from the liver (9/22; 40.9%), with anatomical location not available for two of the cysts. Demographic information was available for 18 cases. Females made up 61.1% (11/18) of the cases. The largest numbers of cases were found in the 31-40 years age group (5/18; 22.7%).

DISCUSSION

This study shows that Echinococcus spp. parasites are circulating in the study area. In order to control the disease, a comprehensive regional surveillance and control program is needed.

Genotyping and phylogenetic analysis of canine parvovirus circulating in Egypt

Aim:

This study aimed to detect and characterize current genotypes of canine parvovirus (CPV) in Egypt during 2018.

Materials and Methods:

A total of 50 fecal swabs were collected from clinically infected domestic dogs of 2-5 months of age, suspected to suffer from CPV infection, from Cairo and Giza Governorates. The samples were subjected to qualitative antigen detection using the rapid test, followed by isolation on Madin-Darby Canine Kidney (MDCK) cells, molecular characterization with partial amplification of VP2 gene using polymerase chain reaction (PCR), followed by sequencing and phylogenetic analysis.

Results:

Out of 50 fecal samples, 20 samples were positive (40%) by Rapid CPV/canine coronavirus Ag Test Kit. These positive samples were cultured successfully on MDCK cells. Nine randomly chosen samples out of 30 apparently negative samples were amplified using PCR with primers Hfor and Hrev to yield a typical 630 bp fragment. Then, six randomly chosen samples out of nine were amplified using PCR with primers Pbs and Pbas to yield a typical 427 bp fragment. Sequencing, BLAST analysis and assembly of the two fragments (630 bp and 427 bp) to produce 912 bp fragments, in the six samples, revealed two serotypes CPV-2b and CPV-2c. The obtained strains were submitted to GenBank and given accession numbers MK642272, MK642273, MK642274, MK642275, MK642276, and MK642277. Phylogenetic analysis of the Egyptian strains serotype 2b illustrated that they were closely related to Thailand strains (accession numbers KP715709, KP715694, KP715701, and KP715700); while Egyptian strains serotype 2c was closely related to Thailand strains (accession numbers MH711894 and MH711902), Taiwanese strain (KU244254), Chinese strain (MF467242), and Vietnamese strain (accession number LC216910).

Conclusion:

The current research recommends further epidemiological studies to assess the extent of the occurrence of different serotypes of CPV in Egypt and the efficiency of imported and locally produced vaccines in protection against CPV infection.

Dynamic evolution of canine parvovirus in Thailand

Background and Aim:

According to the previous study, the circulating canine parvovirus (CPV) in Thailand is 2a and 2b. Nowadays, CPV mutants, including CPV-2c, have been identified in many parts of the world. This study aimed to investigate the genetic diversity of the circulating CPV in Thailand.

Materials and Methods:

Eighty-five CPV-positive fecal samples were obtained from dogs with either acute hemorrhagic diarrhea or diarrhea. The complete VP2 gene of these samples was amplified using VP2 specific primers and polymerase chain reaction (PCR). The obtained full-length VP2 sequences were analyzed and a phylogenetic tree was constructed.

Results:

Sixty and 25 CPV-positive fecal samples were collected in 2010 and 2018, respectively. Thirty-four samples were new CPV-2a and 31 samples were new CPV-2b due to amino acids substitution at position 297 (Ser-Ala). In 2018, 5 new CPV-2a, 19 CPV-2c, and 1 feline panleukopenia virus (FPV) were found, but no new CPV-2b was detected. Moreover, most of the CPV in this study had amino acids mutations at positions 324 and 440. The phylogenetic construction demonstrated the close relationship between the current new CPV-2a with the previous CPV-2a reported from Thailand, China, Uruguay, Vietnam, Singapore, and India. Interestingly, the current new CPV-2b in this study was not closely related to the previous CPV-2b reported in Thailand. The CPV-2c in this study was closer to Asian CPV-2c and further from either European or South America CPV-2c. Interestingly, FPV was identified in a diarrhea dog.

Conclusion:

The evolution of CPV in Thailand is very dynamic. Thus, it is important to monitor for CPV mutants and especially the clinical signs relating to these mutants to conduct surveillance for the emergence of new highly pathogenic CPV in the future.

Spread of Cystic Echinococcosis in Pakistan Due to Stray Dogs and Livestock Slaughtering Habits: Research Priorities and Public Health Importance

Background: Cystic echinococcosis (CE) is a global zoonotic parasitic disease caused by the larval stage of Echinococcus granulosus and it has been reported from both livestock and humans in Pakistan. The definitive host of E. granulosus is the dog, and the large number of stray dogs in Pakistan contributes to the spread of CE. However, there is little information between stray dogs and CE relation in the country. Methods: During the study, total 123 butcher's shops and abattoirs were included for collection of data relating to the hydatid cyst prevalence in slaughtered animals (sheep, goat, cattle, and buffaloes). The number of animals slaughtered in each butcher's shop during sampling period was also recorded, and the association of the shop environment with dogs was inspected. Results: Data was collected for CE from 123 butcher's shops in Rawalpindi and Islamabad, Pakistan. The slaughtering rate the in the butcher's shops was 2-10 animals/day including sheep/goat/cattle and buffaloes. The overall prevalence of CE in all examined animals was 2.77%. In buffaloes the higher prevalence was recorded as compared to other hosts. The findings showed that lung and liver were most affected organs and majority (59%) of the cysts were fertile in infected animals. The presence of a large number of stray dogs were an important factor in the spread of CE. They were rarely vaccinated, have easy access to infected offal at slaughtering site and had insufficient or inappropriate anthelmintic treatment. Conclusions: The most pressing need is to raise public awareness of this huge problem by considering CE a major ailment and promoting the collection and mapping of epidemiological data. Efficient CE control is required, especially treating dogs with antiparasitic drugs, for which government support and affiliation with the veterinary sector is essential.

Emergence of canine parvovirus type 2c in domestic dogs and cats from Thailand

Canine parvovirus type 2 (CPV-2) is an important pathogen causing haemorrhagic enteritis in domestic dogs and wildlife worldwide. In early 2000, canine parvovirus type 2c (CPV-2c) was first reported and subsequently became a predominant subtype circulating in Europe and the Americas. CPV-2c has also been reported in Asia, including cases in China, India, Taiwan and Vietnam. However, CPV-2c has never been reported in Thailand. In this study, we conducted viral enteric disease surveillance in dogs and cats in Thailand during 2016-2018. During 20 months of surveillance, 507 rectal swab samples were collected from dogs (n = 444) and cats (n = 63) with and without clinical signs. The samples were examined for parvovirus by using VP2 gene-specific PCR for parvovirus. Our results showed that the positivity of canine parvovirus (CPV) was 29.95% and that of feline parvovirus (FPV) was 58.73%. In this study, we characterized 34 parvoviruses by VP2 gene sequencing. Moreover, two Thai-CPV-2 (Dog/CU-24 and Cat/CU-21) were characterized by whole genome sequencing. The phylogenetic results showed that Thai-CPV-2 had the highest nucleotide identities and clustered with Asian-CPV-2c but were in separate subclusters from the North American and European CPV-2c. Similarly, whole genome analyses showed that Thai-CPVs are closely related to Asian-CPV-2c, with unique amino acids at positions 297A, 324I, 370R and 426E. In summary, our results demonstrated the emergence of Asian-CPV-2c in dogs and cats in Thailand. Thus, the surveillance of CPV-2 in domestic dogs and cats should be further conducted on a larger scale to determine the dynamics of predominant variants and their distributions in the country and in the Southeast Asia region.