Phylogenetic and Geospatial Evidence of Canine Parvovirus Transmission between Wild Dogs and Domestic Dogs at the Urban Fringe in Australia

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.

Identification and Genome Characterization of Novel Feline Parvovirus Strains Isolated in Shanghai, China

Feline panleukopenia virus (FPV) is the causative agent of hemorrhagic gastroenteritis in feline animals. FPV has been evolving over time, and there have been several different strains of the virus identified. Some of these strains may be more virulent or more resistant to current vaccines than others, which highlights the importance of ongoing research and monitoring of FPV evolution. For FPV genetic evolution analysis, many studies focus on the main capsid protein (VP2), but limited information is available on the nonstructural gene NS1 and structural gene VP1. In the present study, we firstly isolated two novel FPV strains circulating in Shanghai, China, and performed full-length genome sequencing for the desired strains. Subsequently, we focused on analyzing the NS1, VP1 gene, and the encoding protein, and conducted a comparative analysis among the worldwide circulating FPV and Canine parvovirus Type 2 (CPV-2) strains, which included the strains isolated in this study. We found that the 2 structural viral proteins, VP1 and VP2, are splice variants, and VP1 has a 143 amino-acid-long N-terminal compared to VP2. Furthermore, phylogenetic analysis showed that divergent evolution between FPV and CPV-2 virus strains were clustered mostly by country and year of detection. In addition, much more continuous antigenic type changes happened in the process of CPV-2 circulating and evolution compared to FPV. These results stress the importance of the continuous study of viral evolution and provide a comprehensive perspective of the association between viral epidemiology and genetic evolution.

T598 and T601 phosphorylation sites of canine parvovirus NS1 are crucial for viral replication and pathogenicity

Canine parvovirus-2 (CPV-2) is an important pathogen causing severe diseases in dogs and other wild carnivores. Phosphorylation of NS1 may be related to CPV-2 pathogenicity, but the exact mechanism is unclear. Here, we conducted parvovirus disease surveillance in Shaanxi Province of China and 51 fecal swabs were detected to be infected with CPV-2. The 7 CPV-2 strains were identified, all of which belonged to CPV-2c. The complete genome sequence of one of the strains (CPV-2c XY) was cloned into pKQLL plasmid to construct a full-length infectious clone plasmid pX-CPV-2c, which carried a genetic marker. The plasmid pX-CPV-2c was transfected into F81 cells for virus rescue. And the rescued virus, which was designed as X-CPV-2c, showed the similar biological property to parental CPV-2c XY in vitro and in vivo. We further constructed four NS1 phosphorylation site mutant strains (X-CPV-2c^T584A, X-CPV-2c^S592A, X-CPV-2c^T598A/T601A and X-CPV-2c^T617A) on the basis of X-CPV-2c. After the analysis and comparison of biological characteristics, the low pathogenic strain X-CPV-2c^T598A/T601A was further screened out, which emphasized the importance of phosphorylation sites 598 T/601 T for the pathogenicity of CPV-2. Overall, our data indicated that T598 and T601, the C-terminal phosphorylation site of CPV-2 NS1, play important roles in viral pathogenicity and laid the foundation for the development of new attenuated live vaccine vectors.

Circulation of diverse protoparvoviruses in wild carnivores, Italy

Protoparvovirus is a monophyletic viral genus that includes the species Carnivore protoparvovirus-1 infecting domestic and wild carnivores. In this paper, the results of an epidemiological survey for Carnivore protoparvovirus-1 in wild carnivores in Italy are reported. Overall, 34 (11.4%) out of 297 tested animals were positive for Carnivore protoparvovirus-1, but the frequency of detection was much higher in intestine (54%) than in spleen samples (2.8%), thus suggesting that the intestine is the best sample to collect from wild animals for parvovirus detection. Feline panleukopenia virus (FPV) was detected in red foxes (Vulpes vulpes) (2.8%, 7/252) and Eurasian badgers (Meles meles) (10%, 1/10), whilst canine parvovirus (CPV) was found in wolves (54.3%, 19/35), Eurasian badgers (60%, 6/10) and one beech marten (Martes foina) (100%, 1/1), with more than one parvovirus type detected in some animals. Protoparvoviral DNA sequences from this study were found to be related to CPV/FPV strains detected in Asia and Europe, displaying some amino acid changes in the main capsid protein VP2 in comparison with other parvovirus strains from wildlife. In particular, the two most common mutations were Ile418Thr and Ala371Gly, which were observed in 6/12 (50%) and 5/12 (41.7%) of the CPV sequences from this study. Continuous surveillance for parvoviruses in wild carnivores and genetic analysis of the detected strains may help obtain new insight into the role of these animals in the evolution and epidemiology of carnivore parvoviruses.

Simultaneous detection of duck circovirus and novel goose parvovirus via SYBR green I-based duplex real-time polymerase chain reaction analysis

Beak atrophy and dwarfism syndrome (BADS) is commonly caused by co-infection with duck circovirus (DuCV) and novel goose parvovirus (NGPV). Therefore, concurrent detection of both viruses is important for monitoring and limiting BADS, although such a diagnostic test has not been reported. In this study, we developed a duplex, SYBR Green I-based real-time polymerase chain reaction (PCR) assay to enable the simultaneous detection of DuCV and NGPV. The assay readily distinguished between the two viruses, based on their different melting temperatures (Tm), where the Tm for DuCV was 80 °C and that for NGPV was 84.5 °C. Other non-target duck viruses that were tested did not show melting peaks. The detection limit of the duplex assay was 10¹ copies/μL for both viruses. This method exhibited high repeatability and reproducibility, and both the inter-assay and intra-assay variation coefficients were <1.6%. Thirty-one fecal samples were collected for clinical testing using real-time PCR analysis, and the results were confirmed using sequencing. The rate of co-infection was 6.5%, which was consistent with the sequencing results. This duplex real-time PCR assay offers advantages over other tests, such as rapid, sensitive, specific, and reliable detection of both viruses in a single sample, which enables the quantitative detection of DuCV and NGPV in clinical samples. Using this test may be instrumental in reducing the incidence of BADS and the associated economic losses in the duck and goose industries.

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SYBR Green based PCR to simultaneously detect duck circovirus and goose parvovirus.

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The assay had specificity, sensitivity and reproducibility.