Genetic Analysis of Feline Panleukopenia Virus Full-length VP2 Gene in Domestic Cats Between 2006-2008 and 2012-2014, Portugal

Genetic characterization of the parvovirus full-length VP2 gene in domestic cats in Brazil

Feline parvovirus (FPV) and canine parvovirus (CPV) are over 98% identical in their DNA sequences, and the new variants of CPV (2a/2b/2c) have gained the ability to infect and replicate in cats. The aim of this study was to determine the genetic diversity in the VP2 gene of parvovirus strains circulating in domestic cats in Brazil during a 10-year period (2008-2017). For parvovirus screening, specific PCR was performed, and 25 (34.7%) of 72 cats tested positive. The PCR-positive samples were further subjected to full-length VP2 sequencing (1755 bp), and eight sequences (36%) were characterized as FPV, seven (28%) as CPV-2a and (32%) nine (36%) as CPV-2b. One sequence (RJ1085/11) showing typical CPV amino acid (aa) at residues 80 R, 93 N, 103 A, 232 I, and 323 N could not be characterized at this time. The sequences in this study displayed aa changes previously described for FPV (A14T, A91S, I101T, N564S, and A568G) from cats and CPV-2a/2b (S297N and Y324L) from dogs. However, the Y324L mutation has not yet been reported in any CPV-2a/2b strains from cats. Phylogenetic analysis supported the division of these sequences into two well-defined clades, clade 1 for FPV and clade 2 for CPV2a/2b. Unusually, the sequence RJ1085/11 was grouped separately. Two recombination breakpoints were detected by Bootscan and 3Seq methods implemented in the RDP4. This study is the first report of CPV-2a/2b in cats in Brazil. The detection of FPV strains with mutations characteristic of CPV indicates that Brazilian FPV strains have undergone genetic changes.

A novel loop-mediated isothermal amplification (LAMP) assay to diagnose feline panleukopenia

Protoparvovirus carnivoran1, known commonly as feline panleukopenia virus (FPV) is a highly contagious and environmentally stable parvovirus of domestic as well as wild felids. A rapid and robust diagnostic tool will aid in implementing prompt treatment and control measures. A loop-mediated isothermal amplification (LAMP) as a point-of-care diagnostic tool for diagnosing feline panleukopenia was standardised using faecal samples of cats. The assay will reduce the cost and time required to diagnose feline panleukopenia. A set of two outer primers (F3 and B3) and two inner primers (FIP and BIP) were designed to target the viral polypeptide (VP2) gene of FPV. Optimisation of the LAMP reaction was done at 60 °C for one hour after an initial denaturation at 95 °C for five minutes. Visualisation of the result based on the addition of SYBR Green 1 dye offered an easy and reliable diagnosis. The detection limit of the standardised LAMP assay was as low as 1.25 ng/μl of the target DNA. Species specificity of the LAMP primers revealed no amplification of the non-target DNA of any other species except that of the canine parvovirus DNA template. DNA extracted from 100 PCR-positive and 20 PCR-negative faecal samples were subjected to the standardised assay and compared with PCR. Analysis of the results revealed that the LAMP assay was 100% sensitive and 90% specific compared to PCR. The LAMP assay could be a reliable tool for the point-of-care diagnosis of feline panleukopenia in limited resource settings.

China-origin G1 group isolate FPV072 exhibits higher infectivity and pathogenicity than G2 group isolate FPV027

Introduction

Feline parvovirus (FPV), a single-stranded DNA virus, is accountable for causing feline panleukopenia, a highly contagious and often lethal disease that primarily affects cats. The epidemiology prevalence and pathogenicity of FPV in certain regions of China, however, remains unclear. The aim of this research was to investigate the epidemiology of FPV in different regions of China in 2021 and compare its infectivity and pathogenicity.

Methods

In this research, a total of 36 FPV strains were obtained from diverse regions across China. Phylogenetic analysis was performed based on the VP2 and NS1 sequences, and two representative strains, FPV027 and FPV072, which belonged to different branches, were selected for comparative assessment of infectivity and pathogenicity.

Results and discussion

The results revealed that all strains were phylogenetically classified into two groups, G1 and G2, with a higher prevalence of G1 strains in China. Both in vitro and in vivo experiments demonstrated that FPV072 (G1 group) exhibited enhanced infectivity and pathogenicity compared to FPV027 (G2 Group). The structural alignment of the VP2 protein between the two viruses revealed mutations in residues 91, 232, and 300 that may contribute to differences in infectivity and pathogenicity. The findings from these observations will contribute significantly to the overall understanding of the molecular epidemiology of FPV in China and facilitate the development of an effective FPV vaccine.

Feline Parvovirus Lethal Outbreak in a Group of Adult Cohabiting Domestic Cats

Feline panleukopenia is a highly contagious and often fatal disease in cats. The virus, known as feline panleukopenia virus (FPV), primarily affects kittens and unvaccinated cats. It is transmitted through contact with infected cats or their bodily fluids, as well as contaminated objects and environments. The diagnosis of FPV infection can be confirmed through a combination of clinical signs, blood tests, and fecal testing. Prevention through vaccination is recommended for all cats. This case report describes an outbreak of feline panleukopenia in a group of unvaccinated domestic cats that resulted in acute mortality. The lesions were evaluated using histopathology, and the specific viral strain was characterized using molecular techniques. The clinical course of the outbreak was peracute, with a hemorrhagic pattern and 100% of lethality. The observed clinical-pathological pattern was unusual; nevertheless, molecular studies did not highlight peculiar genomic features of the parvovirus isolate. The outbreak affected 3 out of 12 cats in a very short time. However, the prompt application of biosecurity measures and vaccination resulted in an effective interruption of virus spread. In conclusion, we could assume that the virus found the ideal conditions to infect and replicate at high titers, resulting in a particularly aggressive outbreak.

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.

Molecular investigation of Feline Panleukopenia in an endangered leopard (Panthera pardus) - a case report

BACKGROUND

Feline Panleukopenia is an important disease of cats and has been reported worldwide. The disease is caused by a non-enveloped, single-stranded DNA virus; Feline Panleukopenia Virus (FPLV), belonging to the Parvoviridae family. The disease causes significant mortality in unvaccinated kittens. The disease has been well documented in companion animals. However, only a few reports have surfaced from the wild.

CASE PRESENTATION

An orphan leopard cub was presented to Wildlife Rescue Centre, Nagpur, for further care; the leopard was kept under quarantine. On day 22 of the quarantine, the leopard showed inappetence, lethargy and depression and did not consume the offered carabeef (Day 0 of treatment). The leopard was examined clinically and was found to have a temperature of 102°F; blood was collected and analysed. On day one, the leopard exhibited bloody diarrhoea, inappetence, fever and depression. The leopard was rationally treated with fluids, antibiotics, multi-vitamins, haemostatics and haematinics. To gain qualitative insights into the epidemiological aspect of the disease, molecular investigation, including Polymerase Chain Reaction (PCR) and qPCR (Quantitative Polymerase Chain Reaction), were utilized to confirm the infection. The amplicon was sequenced and was found to be similar to sequences of FPLV reported domestic cats and other wild felids from India and abroad. Phylogenetic analysis was performed to understand the evolutionary relationship of the virus with previously reported sequences of FPLV. Sequences were submitted to National Center for Biotechnology Information (NCBI) and were allotted accession numbers.

CONCLUSION

The infection in endangered leopard cubs could be managed with prompt fluid therapy, antibiotics and support treatment, ensuring an uneventful recovery. Molecular investigation and sequencing efforts can provide valuable data on epidemiology and the evolutionary relationship of the virus with the circulating strains in the field. The study has implications in the preventive management of FPLV in captivity and the selection of strains for inclusion in vaccines meant for the wild felids.

A Retrospective Study of Viral Molecular Prevalences in Cats in Southern Italy (Campania Region)

From 2019 to 2021, a retrospective molecular study was conducted in the Campania region (southern Italy) to determine the prevalence of viral diseases in domestic cats. A total of 328 dead animals were analyzed by Real-Time PCR for the presence of feline panleukopenia virus (FPV), feline leukemia virus (FeLV), feline enteric coronavirus (FCoV), rotavirus (RVA), feline herpesvirus type 1 (FHV-1), and feline calicivirus (FCV). The possible presence of SARS-CoV-2 was also investigated by Real-Time PCR. The cats included in this study were specifically sourced and referred by local veterinarians and local authorities to the Zooprofilactic Experimental Institute of Southern Italy (IZSM) for pathological evaluation. The samples consisted of owners, catteries, and stray cats. Results revealed: 73.5% positive cats for FPV (189/257), 23.6% for FeLV (21/89), 21.5% for FCoV (56/266), 11.4% for RVA (16/140), 9.05% for FeHV-1 (21/232), and 7.04 for FCV (15/213). In contrast, SARS-CoV-2 was never detected. FPV was more prevalent in winter (p = 0.0027). FCoV FHV-1, FCV, and RVA predominated in autumn, whereas FeLV predominated in summer. As expected, viral infections were found more frequently in outdoor and shelter cats than in indoor ones, although no statistical association was found between animal lifestyle and viral presence. The study showed a high prevalence of FPV, FeLV, and FCoV and a moderate prevalence of RVA, FHV-1, and FCV. Moreover, the prevalence of these pathogens varied among the cat populations investigated.

Circulation of heterogeneous Carnivore protoparvovirus 1 in diarrheal cats and prevalence of an A91S feline panleukopenia virus variant in China

Cats are susceptible to panleukopenia virus (FPV) and canine parvovirus type 2 (CPV-2) infection. FPV has been recognized as relatively conservative in genetic evolution compared to CPV-2, but information regarding FPV variations in cats are still limited. The aim of this study was to investigate the molecular prevalence of FPV and CPV-2 variants among cats in China. From April 2019 to December 2021, 193 diarrheal fecal samples of cats were collected from Southwest China and 127 (65.80 %) samples tested positive to Carnivore protoparvovirus 1. FPV, CPV-2 and some their genomic variants were identified from positive samples, indicating a heterogeneous Carnivore protoparvovirus 1 circulation in the cat population in China. Among FPV strains, an A91S FPV mutant reached the detection rate of 39.37 %, which showed that this FPV genomic variant has been prevalent in the tested cats. Moreover, 7 strains of A91S FPV variants were isolated and purified successfully using F81 cells, and the genomes were sequenced. Phylogenetic trees based on the nearly complete genomic sequences, VP2 and NS1 nucleotide sequences showed that the A91S FPV variants were located in the FPV clade, but all clustered into a separate branch. Structural prediction showed that A91S mutation in VP2 protein extended the random coil of aa residues from 92-95 to 91-95. Moreover, the analysis of all complete VP2 sequences of FPV and CPV-2 available in the GenBank database revealed that the A91S FPV variant has been prevalent in China since 2017 and has reported in four other countries in cats. Thus, our study revealed that heterogeneous Carnivore protoparvovirus 1 are circulating in the cat population in China, and first reported the prevalence and genomic characteristics of the A91S FPV variant, which contributed to a better understanding of the molecular prevalence and genetic evolution of FPV in cats. This article is protected by copyright. All rights reserved.

A duplex SYBR green I-based real-time polymerase chain reaction assay for concurrent detection of feline parvovirus and feline coronavirus

Feline coronavirus (FCoV) contains two serotypes, feline enteric coronavirus (FECV) and Feline infectious peritonitis virus (FIPV). FECV and feline parvovirus (FPV) can cause similar clinical symptoms in cats, such as diarrhea. The objective of this study was to establish a duplex SYBR Green I-based quantitative polymerase chain reaction (qPCR) assay for rapid and simultaneous detection of FPV and FCoV. Two pairs of specific PCR primers were designed to target fragments of the VP2 gene of FPV and of the 5' UTR gene of FCoV, respectively. The assay distinguished between the two viruses based on the melting curves (melting temperatures 77.0 ± 0.5 °C [FPV] and 80.5 ± 0.5 °C [FCoV]). The minimum limits of FPV and FCoV detection were 4.74 × 10¹ copies/μL and 7.77 × 10¹ copies/μL, respectively. The assay showed excellent reproducibility and reliability, based on the mean coefficient of variation. In conclusion, this novel duplex SYBR Green I-based qPCR assay is sensitive and can specifically, reliably, and rapidly detect FPV and FCoV (co-)infections.

Novel parvovirus in cats, China

Parvovirus is a common element of the feline virus group and usually causes gastroenteritis and leukopenia in cats. In this study, we identified a novel protoparvovirus from the Chinese domestic cats, which is genetically similar to canine bufavirus (98.0%-99.8%), but sharing low amino acid identities in the viral structural proteins 2 (VP2) (36.1-37.2%) to the well-known canine parvovirus type 2 and feline panleukopenia virus. This virus was provisionally designated as feline bufavirus (FBuV). Screening of fecal samples revealed a prevalence of 7.4% (19/257) in domestic cats. Diarrhea was present in 52.6% (10/19) of cats positive for FBuV. However, statistical analysis showed no association between FBuV and clinical signs. VP2 gene of the 19 field FBuV was sequenced and phylogenetic analysis demonstrated that FBuV determined from China had a genetic diversity. This study will strengthen the understanding of the epidemiology and genetic diversity of bufavirus and provide a foundation for further studies.

Genetic characterization of parvoviruses in domestic cats in Henan province, China

Feline panleukopenia virus (FPV) and canine parvovirus (CPV) infections are highly contagious and cause serious enteric diseases, with high fatality rates of cats and dogs. Given the importance of cats as a potential source of genetic diversity for parvoviruses, parvovirus strains detected in cats with gastroenteritis signs were analysed, and molecular characterisation, sequence analysis and phylogeny were evaluated on the VP2 gene. The results showed that FPV, new CPV-2a, and CPV-2 are co-circulating in the cat population in Henan province of China. Moreover, CPV-2 strains (F2016020, and F2016021) with Ser297Ala substitution in VP2 protein was for the first time detected in cats with clinical gastroenteritis. This study provided new important findings about the evolutionary of parvovirus infection in domestic cats.

Molecular analysis of carnivore Protoparvovirus detected in white blood cells of naturally infected cats

Background

Cats are susceptible to feline panleukopenia virus (FPV) and canine parvovirus (CPV) variants 2a, 2b and 2c. Detection of FPV and CPV variants in apparently healthy cats and their persistence in white blood cells (WBC) and other tissues when neutralising antibodies are simultaneously present, suggest that parvovirus may persist long-term in the tissues of cats post-infection without causing clinical signs. The aim of this study was to screen a population of 54 cats from Sardinia (Italy) for the presence of both FPV and CPV DNA within buffy coat samples using polymerase chain reaction (PCR). The DNA viral load, genetic diversity, phylogeny and antibody titres against parvoviruses were investigated in the positive cats.

Results

Carnivore protoparvovirus 1 DNA was detected in nine cats (16.7%). Viral DNA was reassembled to FPV in four cats and to CPV (CPV-2b and 2c) in four cats; one subject showed an unusually high genetic complexity with mixed infection involving FPV and CPV-2c. Antibodies against parvovirus were detected in all subjects which tested positive to DNA parvoviruses.

Conclusions

The identification of FPV and CPV DNA in the WBC of asymptomatic cats, despite the presence of specific antibodies against parvoviruses, and the high genetic heterogeneity detected in one sample, confirmed the relevant epidemiological role of cats in parvovirus infection.