Family Parvoviridae Research Articles

Viral fossils in marsupial genomes: secret cellular guardians

Genomic viral integrations, termed endogenous viral elements (EVEs), are fragments of viruses in host chromosomes that provide information about viral evolution and could even help protect the host from infection. In the present study we examined EVEs in thirteen different Australian marsupial species to identify trends in their integration, commonality and to investigate their possible cellular function. We found that marsupial EVEs are commonly derived from viruses of the Bornaviridae, Filoviridae and Parvoviridae families, and circulated up to 160 million years ago. We also show the EVEs are actively transcribed into both long and short RNA molecules in marsupials, and propose they are involved in a cellular defence mechanism to protect the germline from viral genomic invasion.

Update on Canine Parvovirus Infection: A Review from the Literature

| Canine parvovirus (CPV) enteritis is a highly contagious, virulent, acute, and fatal gastrointestinal viral disease that fundamentally transforms the pups and collapses the body’s posthaste branching organs, such as bone marrow, lymph node, and the flimsy cell of the intestine, causing bloody diarrhea amidst a high mortality and morbidity rate. CPV is distributed in the family Parvoviridae beneath the subfamily Parvovirinae that pertains to the genus Protoparvoviorus with a high genomic replacement unlike other DNA virus; the organism is primarily segmented into three forms acknowledged as (CPV-2a, CPV-2b, and CPV-2c), which resembles to be liable for the infection’s statewide spread. For transmission, the fecal-oral pathway is deemed the most obvious route than other permissible routes. Moreover, spreading through contact interactions, environmental pollutants, and the host reservoir, like a stray dog, could be feasible. Distressingly, such a pathogen is currently endemic in Asian nations, including India, Bangladesh, Sri Lanka and China. Thus, the literature review encompassed comprehensive knowledge concerning contemporary disease occurrence with causes and transmission imperative for management practice. Besides, the study converged on afresh advanced treatment procedures, vaccine progressions, and public awareness efforts, which can be a baseline for the policymaker, veterinarians and pet owner to limit further outbreaks.

The Main DNA Viruses Significantly Affecting Pig Livestock.

Swine DNA viruses have developed unique mechanisms for evasion of the host immune system, infection and DNA replication, and finally, construction and release of new viral particles. This article reviews four classes of DNA viruses affecting swine: porcine circoviruses, African swine fever virus, porcine parvoviruses, and pseudorabies virus. Porcine circoviruses belonging to the Circoviridae family are small single-stranded DNA viruses causing different diseases in swine including poly-weaning multisystemic wasting syndrome, porcine dermatitis and nephropathy syndrome, and porcine respiratory disease complex. African swine fever virus, the only member of the Asfivirus genus in the Asfarviridae family, is a large double-stranded DNA virus and for its propensity to cause high mortality, it is currently considered the most dangerous virus in the pig industry. Porcine parvoviruses are small single-stranded DNA viruses belonging to the Parvoviridae family that cause reproductive failure in pregnant gilts. Pseudorabies virus, or suid herpesvirus 1, is a large double-stranded DNA virus belonging to the Herpesviridae family and Alphaherpesvirinae subfamily. Recent findings including general as well as genetic classification, virus structure, clinical syndromes and the host immune system responses and vaccine protection are described for all four swine DNA virus classes.

Morphofunctional changes in sable organs and tissues in parvovirus enteritis

High resistance of the caged sable to infectious diseases was noted during the long-term practice of fur-bearing animals breeding. But in recent years, local epizootics in sables, manifested by enteritis, have increasingly begun to appear in fur farms. Parvovirus enteritis was established in the laboratory study of pathological material from sick animals by PCR and RHA. The causative agent of this disease is a virus belonging to the Parvoviridae family, the genome of which is represented by single-stranded DNA. The structure of the virion makes all parvoviruses very stable in the external environment. Carnivore parvoviruses penetrate almost all cells of the body, and reproduce only in the most mitotically active tissues, which is the constantly reproducing intestinal epithelium. Parvoviruses are characterized, on the one hand, by a high (up to 98.5%) degree of genome identity and, on the other hand, by pronounced antigenic variability and genomic polymorphism. This indicates the possibility of interspecific transmission and damage to side (random) hosts, which can serve as a reservoir for recombination and selection of strains with new antigenic properties and species tropism. Since 2017, employees of the Research Institute of Fur-Bearing and Rabbit Breeding named after V.A. Afanasyev, monitoring studies are carried out in various animal farms of the Russian Federation, where sable is bred and from pathological material from sables that have died with clinical signs of enteritis, the DNA of parvovirus is often isolated by PCR. Since the totality of the data obtained suggests the danger of the disease for the unique Russian sable with parvovirus enteritis, the study of morphological and functional changes in sables is an urgent task.

Human Parvovirus B19 Infection Among Blood Donors in North-East of Iran

Background: Human parvovirus B19 is a single-stranded DNA and non-enveloped virus which belongs to the Parvoviridae family. The virus spreads through respiratory secretions and perinatal blood. B19 may cause serious complications in patients with cellular immunodeficiency that have no detectable antibodies to B19, such as aplastic crises in solid organs. Objectives: The present study aimed to investigate the prevalence of parvovirus B19 and to evaluate the presence of B19 DNA among blood donors in Golestan Province. Methods: Sera of 400 blood donors in Golestan Province who were negative for HIV, HbsAg, and HCV were tested for both IgG and IgM anti-B19 virus antibodies using the ELISA method, following which all sera were tested for the presence of B19 DNA by semi-nested PCR. Results: 242 (out of 400) subjects (60.5%; 95% CI) were positive for anti-B19 IgG, and 158 were negative for IgG antibody (39.5%; 95% CI). Moreover, all asymptomatic blood donors were negative for anti-B19 IgM. No viral genome was found in serum samples of donors. Conclusions: Since no viral genome was found in the donors' serum samples and the relatively high prevalence of anti HPV- B19 IgG in blood donors, it can be concluded that the possibility of B19 transmission through blood transfusion is low. However, special caution should be taken when transfusing blood to the high-risk groups such as pregnant women, immune-deficient patients, and those with hematological problems, particularly regarding IgG anti- HPV- B19 antibodies (HPV- B19-safe).

Detection and genetic characterization of a novel parvovirus (family Parvoviridae) in barn owls (Tyto alba) in Hungary.

In this study, a novel parvovirus (gyb-MR02/2015/HUN, MT580795) was detected in barn owls (Tyto alba) and genetically characterized using viral metagenomics and PCR methods. The NS1 and VP1 proteins of gyb-MR02/2015/HUN share only 45.4% and 50.1% amino acid sequence identity, respectively, to the corresponding proteins of peafowl parvovirus 2 (MK988620), the closest relative. Out of 11 faecal specimens from owls (six from little owls, three from barn owls, and two from long-eared owls), two barn owl samples were positive for the novel parvovirus, which is distantly related to members of the recently established genus Chaphamaparvovirus in the subfamily Hamaparvovirinae. Systematic investigation is necessary to explore the diversity of parvoviruses.

Investigation of human bocavirus in pediatric patients with respiratory tract infection.

Human bocavirus (HBoV) is a linear single-stranded DNA virus belonging to the Parvoviridae family. This study aimed to investigate the incidence of HBoV and co-infections in pediatric patients with symptoms of viral respiratory tract infection. This study included 2,310 patients between the ages of 0-18 in whom HBoV and other respiratory tract viral pathogens were analyzed in nasopharyngeal swab specimens. In the pediatric age group, HBoV was found in 4.5% (105/2310) of the patients and higher in children between the ages of 1 and 5. Mixed infection was detected in 43.8% (46/105) of HBoV positive patients (p = 0.10). Mono and mixed infection rates were higher in outpatients than in inpatients (p < 0.05). Respiratory syncytial virus was significantly higher than the other respiratory viral pathogens (p < 0.001). This study is important as it is one of the rare studies performed on the incidence of HBoV in the Marmara region. In pediatric age group, the incidence of HBoV was found 4.5%. The incidence rate of HBoV in this study was similar to those in studies around the world, but close to low rates. The incidence of HBoV was found higher especially among children between the ages of 1-5 in this study. In addition to the incidence of HBoV, accompanying co-infections in the pediatric age group were also investigated in this study. Since concurrence of RSV, HRV and hMPV with HBoV was the most common it must be considered that there may be more than one agents in patients with symptoms of respiratory tract infection.

Oncolytic H-1 Parvovirus Enters Cancer Cells through Clathrin-Mediated Endocytosis.

H-1 protoparvovirus (H-1PV) is a self-propagating virus that is non-pathogenic in humans and has oncolytic and oncosuppressive activities. H-1PV is the first member of the Parvoviridae family to undergo clinical testing as an anticancer agent. Results from clinical trials in patients with glioblastoma or pancreatic carcinoma show that virus treatment is safe, well-tolerated and associated with first signs of efficacy. Characterisation of the H-1PV life cycle may help to improve its efficacy and clinical outcome. In this study, we investigated the entry route of H-1PV in cervical carcinoma HeLa and glioma NCH125 cell lines. Using electron and confocal microscopy, we detected H-1PV particles within clathrin-coated pits and vesicles, providing evidence that the virus uses clathrin-mediated endocytosis for cell entry. In agreement with these results, we found that blocking clathrin-mediated endocytosis using specific inhibitors or small interfering RNA-mediated knockdown of its key regulator, AP2M1, markedly reduced H-1PV entry. By contrast, we found no evidence of viral entry through caveolae-mediated endocytosis. We also show that H-1PV entry is dependent on dynamin, while viral trafficking occurs from early to late endosomes, with acidic pH necessary for a productive infection. This is the first study that characterises the cell entry pathways of oncolytic H-1PV.

The Effect of Phenoloxidase Activity on Survival Is Host Plant Dependent in Virus-Infected Caterpillars.

An important goal of disease ecology is to understand trophic interactions influencing the host–pathogen relationship. This study focused on the effects of diet and immunity on the outcome of viral infection for the polyphagous butterfly, Vanessa cardui Linnaeus (Lepidoptera: Nymphalidae) (painted lady). Specifically, we aimed to understand the role that larval host plants play when fighting a viral pathogen. Larvae were orally inoculated with the entomopathogenic virus, Junonia coenia densovirus (JcDV) (Family Parvoviridae, subfamily Densovirinae, genus Protoambidensovirus, species Lepidopteran protoambidensovirus 1) and reared on two different host plants (Lupinus albifrons Bentham (Fabales: Fabaceae) or Plantago lanceolata Linnaeus (Lamiales: Plantaginaceae)). Following viral infection, the immune response (i.e., phenoloxidase [PO] activity), survival to adulthood, and viral load were measured for individuals on each host plant. We found that the interaction between the immune response and survival of the viral infection was host plant dependent. The likelihood of survival was lowest for infected larvae exhibiting suppressed PO activity and feeding on P. lanceolata, providing some evidence that PO activity may be an important defense against viral infection. However, for individuals reared on L. albifrons, the viral infection had a negligible effect on the immune response, and these individuals also had higher survival and lower viral load when infected with the pathogen compared to the controls. Therefore, we suggest that host plant modifies the effects of JcDV infection and influences caterpillars’ response when infected with the virus. Overall, we conclude that the outcome of viral infection is highly dependent upon diet, and that certain host plants can provide protection from pathogens regardless of immunity.

No G-Quadruplex Structures in the DNA of Parvovirus B19: Experimental Evidence versus Bioinformatic Predictions.

Parvovirus B19 (B19V), an ssDNA virus in the family Parvoviridae, is a human pathogenic virus, responsible for a wide range of clinical manifestations, still in need of effective and specific antivirals. DNA structures, including G-quadruplex (G4), have been recognised as relevant functional features in viral genomes, and small-molecule ligands binding to these structures are promising antiviral compounds. Bioinformatic tools predict the presence of potential G4 forming sequences (PQSs) in the genome of B19V, raising interest as targets for antiviral strategies. Predictions locate PQSs in the genomic terminal regions, in proximity to replicative origins. The actual propensity of these PQSs to form G4 structures was investigated by circular dichroism spectroscopic analysis on synthetic oligonucleotides of corresponding sequences. No signature of G4 structures was detected, and the interaction with the G4 ligand BRACO-19 (N,N′-(9-{[4-(dimethylamino)phenyl]amino}acridine-3,6-diyl)bis(3-pyrrolidin-1-ylpropanamide) did not appear consistent with the stabilisation of G4 structures. Any potential role of PQSs in the viral lifecycle was then assessed in an in vitro infection model system, by evaluating any variation in replication or expression of B19V in the presence of the G4 ligands BRACO-19 and pyridostatin. Neither showed a significant inhibitory activity on B19V replication or expression. Experimental challenge did not support bioinformatic predictions. The terminal regions of B19V are characterised by relevant sequence and symmetry constraints, which are functional to viral replication. Our experiments suggest that these impose a stringent requirement prevailing over the propensity of forming actual G4 structures.

Footprint of the host restriction factors APOBEC3 on the genome of human viruses.

APOBEC3 enzymes are innate immune effectors that introduce mutations into viral genomes. These enzymes are cytidine deaminases which transform cytosine into uracil. They preferentially mutate cytidine preceded by thymidine making the 5'TC motif their favored target. Viruses have evolved different strategies to evade APOBEC3 restriction. Certain viruses actively encode viral proteins antagonizing the APOBEC3s, others passively face the APOBEC3 selection pressure thanks to a depleted genome for APOBEC3-targeted motifs. Hence, the APOBEC3s left on the genome of certain viruses an evolutionary footprint. The aim of our study is the identification of these viruses having a genome shaped by the APOBEC3s. We analyzed the genome of 33,400 human viruses for the depletion of APOBEC3-favored motifs. We demonstrate that the APOBEC3 selection pressure impacts at least 22% of all currently annotated human viral species. The papillomaviridae and polyomaviridae are the most intensively footprinted families; evidencing a selection pressure acting genome-wide and on both strands. Members of the parvoviridae family are differentially targeted in term of both magnitude and localization of the footprint. Interestingly, a massive APOBEC3 footprint is present on both strands of the B19 erythroparvovirus; making this viral genome one of the most cleaned sequences for APOBEC3-favored motifs. We also identified the endemic coronaviridae as significantly footprinted. Interestingly, no such footprint has been detected on the zoonotic MERS-CoV, SARS-CoV-1 and SARS-CoV-2 coronaviruses. In addition to viruses that are footprinted genome-wide, certain viruses are footprinted only on very short sections of their genome. That is the case for the gamma-herpesviridae and adenoviridae where the footprint is localized on the lytic origins of replication. A mild footprint can also be detected on the negative strand of the reverse transcribing HIV-1, HIV-2, HTLV-1 and HBV viruses. Together, our data illustrate the extent of the APOBEC3 selection pressure on the human viruses and identify new putatively APOBEC3-targeted viruses.

Acute Respiratory Infection in Co-Infection Form of Bacteria and Virus, Human Bocavirus with Streptococcus pneumoniae: A Case Report

Introduction: Human bocavirus (HBoV) belongs to the Parvoviridae family, which has been revealed to be associated with respiratory and gastrointestinal infections in children. There are many reports worldwide on respiratory infection or gastroenteritis caused by this virus. Case Presentation: In a twin case (a girl and a boy), we demonstrated that HBoV infection in combination with Streptococcus pneumonia as co-infection caused the death of a 14-month-old girl with a history of high fever and wheezing. A week later, her brother presented with almost the same symptoms, but only HBoV was found in a nasopharyngeal aspirate sample. Discussion: This case suggests that lower respiratory tract infections due to HBoV may cause severe and life-threatening diseases, resulting in death in combination with a bacterial infection, such as S. pneumonia. The study suggests replacing multiplex PCR as a fast and meticulous method instead of conventional and time-consuming microbiological methods for determining the causative organism for respiratory infections.

Molecular biology and structure of a novel penaeid shrimp densovirus elucidate convergent parvoviral host capsid evolution

The giant tiger prawn (Penaeus monodon) is a decapod crustacean widely reared for human consumption. Currently, viruses of two distinct lineages of parvoviruses (PVs, family Parvoviridae; subfamily Hamaparvovirinae) infect penaeid shrimp. Here, a PV was isolated and cloned from Vietnamese P. monodon specimens, designated Penaeus monodon metallodensovirus (PmMDV). This is the first member of a third divergent lineage shown to infect penaeid decapods. PmMDV has a transcription strategy unique among invertebrate PVs, using extensive alternative splicing and incorporating transcription elements characteristic of vertebrate-infecting PVs. The PmMDV proteins have no significant sequence similarity with other PVs, except for an SF3 helicase domain in its nonstructural protein. Its capsid structure, determined by cryoelectron microscopy to 3-Å resolution, has a similar surface morphology to Penaeus stylirostris densovirus, despite the lack of significant capsid viral protein (VP) sequence similarity. Unlike other PVs, PmMDV folds its VP without incorporating a βA strand and displayed unique multimer interactions, including the incorporation of a Ca2+ cation, attaching the N termini under the icosahedral fivefold symmetry axis, and forming a basket-like pentamer helix bundle. While the PmMDV VP sequence lacks a canonical phospholipase A2 domain, the structure of an EDTA-treated capsid, determined to 2.8-Å resolution, suggests an alternative membrane-penetrating cation-dependent mechanism in its N-terminal region. PmMDV is an observed example of convergent evolution among invertebrate PVs with respect to host-driven capsid structure and unique as a PV showing a cation-sensitive/dependent basket structure for an alternative endosomal egress.

Human Bocavirus 1 Infection of Well-Differentiated Human Airway Epithelium.

Human bocavirus 1 (HBoV1) is a small DNA virus that belongs to the Bocaparvovirus genus of the Parvoviridae family. HBoV1 is a common respiratory pathogen that causes mild to life-threatening acute respiratory tract infections in children and immunocompromised individuals, infecting both the upper and lower respiratory tracts. HBoV1 infection causes death of airway epithelial cells, resulting in airway injury and inflammation. In vitro, HBoV1 only infects well-differentiated (polarized) human airway epithelium cultured at an air-liquid interface (HAE-ALI), but not any dividing human cells. A full-length HBoV1 genome of 5543 nucleotides has been cloned from DNA extracted from a human nasopharyngeal swab into a plasmid called HBoV1 infectious clone pIHBoV1. Transfection of pIHBoV1 replicates efficiently in human embryonic kidney 293 (HEK293) cells and produces virions that are highly infectious. This article describes protocols for production of HBoV1 in HEK293 cells, generation of HAE-ALI cultures, and infection with HBoV1 in HAE-ALI. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Human bocavirus 1 production in HEK293 cells Support Protocol 1: HEK293 cell culture and transfection Support Protocol 2: Quantification of human bocavirus 1 using real-time quantitative PCR Basic Protocol 2: Differentiation of human airway cells at an air-liquid interface Support Protocol 3: Expansion of human airway epithelial cell line CuFi-8 Support Protocol 4: Expansion of human airway basal cells Support Protocol 5: Coating of plastic dishes and permeable membranes of inserts Support Protocol 6: Transepithelial electrical resistance measurement Basic Protocol 3: Human bocavirus 1 infection in human airway epithelium cultured at an air-liquid interface Support Protocol 7: Isolation of infected human airway epithelium cells from inserts Basic Protocol 4: Transduction of airway basal cells with lentiviral vector.

Identification of multiple potential viral diseases in a large urban center using wastewater surveillance

Viruses are linked to a multitude of human illnesses and can disseminate widely in urbanized environments causing global adverse impacts on communities and healthcare infrastructures. Wastewater-based epidemiology was employed using metagenomics and quantitative polymerase chain reaction (qPCR) assays to identify enteric and non-enteric viruses collected from a large urban area for potential public health monitoring and outbreak analysis. Untreated wastewater samples were collected from November 2017 to February 2018 (n = 54) to evaluate the diversity of human viral pathogens in collected samples. Viruses were classified into virus types based on primary transmission routes and reviewed against viral associated diseases reported in the catchment area. Metagenomics detected the presence of viral pathogens that cause clinically significant diseases reported within the study area during the sampling year. Detected viruses belong to the Adenoviridae, Astroviridae, Caliciviridae, Coronaviridae, Flaviviridae, Hepeviridae, Herpesviridae, Matonaviridae, Papillomaviridae, Parvoviridae, Picornaviridae, Poxviridae, Retroviridae, and Togaviridae families. Furthermore, concentrations of adenovirus, norovirus GII, sapovirus, hepatitis A virus, human herpesvirus 6, and human herpesvirus 8 were measured in wastewater samples and compared to metagenomic findings to confirm detected viral genus. Hepatitis A virus obtained the greatest average viral load (1.86 × 107 genome copies/L) in wastewater samples compared to other viruses quantified using qPCR with a 100% detection rate in metagenomic samples. Average concentration of sapovirus (1.36 × 106 genome copies/L) was significantly greater than norovirus GII (2.94 × 104 genome copies/L) indicating a higher burden within the study area. Findings obtained from this study aid in evaluating the utility of wastewater-based epidemiology for identification and routine monitoring of various viruses in large communities. This methodology has the potential to improve public health responses to large scale outbreaks and viral pandemics.

Porcine Parvovirus 7: Evolutionary Dynamics and Identification of Epitopes toward Vaccine Design.

Porcine parvovirus 7 (PPV7) belonging to the genus Chapparvovirus in the family Parvoviridae, has been identified in the USA, Sweden, Poland, China, South Korea and Brazil. Our objective was to determine the phylogeny, estimate the time of origin and evolutionary dynamics of PPV7, and use computer-based immune-informatics to assess potential epitopes of its Cap, the main antigenic viral protein, for vaccines or serology. Regarding evolutionary dynamics, PPV7 had 2 major clades, both of which possibly had a common ancestor in 2004. Furthermore, PPV7 strains from China were the most likely ancestral strains. The nucleotide substitution rates of NS1 and Cap genes were 8.01 × 10−4 and 2.19 × 10−3 per site per year, respectively, which were higher than those reported for PPV1-4. The antigenic profiles of PPV7 Cap were revealed and there were indications that PPV7 used antigenic shift to escape from the host’s immune surveillance. Linear B cell epitopes and CD8 T cell epitopes of Cap with good antigenic potential were identified in silico; these conserved B cell epitopes may be candidates for the PPV7 vaccine or for the development of serological diagnostic methods.

Multi-host dispersal of known and novel carnivore amdoparvoviruses.

Amdoparvoviruses (family Parvoviridae) are ssDNA viruses that cause an immune complex-mediated wasting syndrome in carnivores. They are multi-host pathogens and cross-species infection is facilitated by the fact that viral entry is mediated by cellular Fc receptors recognizing antibody-coated viruses. We developed a pan-amdoparvovirus PCR and screened tissue samples from 666 wild carnivores (families Felidae, Canidae, and Mustelidae) from Newfoundland or Labrador (Canada) and molecularly characterized the identified strains. Fifty-four out of 666 (8.1%) animals were amdoparvovirus-positive. Infection rate was the highest in American mink (34/47, 72.3%), followed by foxes (Arctic and red foxes, 13/311, 4.2%), lynx (2/58, 3.5%), and American martens (5/156, 3.4%). No virus was detected in samples from 87 coyotes and 17 ermines. Viruses from Newfoundland were classified as Aleutian mink disease virus (AMDV). Mink harvested near AMDV-affected fur farms had higher prevalence (24/24, 100%) than other mink (10/23, 43.5%; P < 0.001) and their viruses were phylogenetically closely related to those from farms, while most viruses from other mink were in other clades. Strains from three foxes and two lynx were highly related to mink strains. This proves that farms disperse AMDV that subsequently spreads among wild mink (maintenance host) and transmits to other spillover carnivore hosts. In Labrador two novel viruses were identified, Labrador amdoparvovirus 1 (LaAV-1) found in foxes (9/261, 3.5%) and martens (5/156, 3.4%), and LaAV-2 found in one fox (0.4%). LaAV-1 fulfills all requirements to be classified as a novel species. LaAV-1 was most similar to viruses of mink and skunks (AMDV and skunk amdoparvovirus (SKAV)) while LaAV-2 was more closely related to other viruses infecting canids. LaAV-1 capsid proteins were almost indistinguishable from those of AMDV in some regions, suggesting that LaAV-1 could be a virus of mustelids that can infect foxes. While intensive farming practices provide occasions for inter-species transmission in farms, niche overlap or predation could explain cross-species transmission in the wild, but competition among sympatric species reduces the chances of direct contacts, making this an infrequent event. Pan-amdoparvovirus detection methods in wide epidemiological investigations can play a crucial role in defining amdoparvoviral ecology and evolution and discovering novel viruses.

Virome of crab-eating (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) from southern Brazil and Uruguay

Crab-eating (Cerdocyon thous) and Pampas foxes (Lycalopex gymnocercus) are wild canids distributed in South America. Domestic dogs (Canis lupus familiaris) and wild canids may share viral pathogens, including rabies virus (RABV), canine distemper virus (CDV), and canine parvovirus 2 (CPV-2). To characterize the virome of these wild canid species, the present work evaluated the spleen and mesenteric lymph node virome of 17 crab-eating and five Pampas foxes using high-throughput sequencing (HTS). Organ samples were pooled and sequenced using an Illumina MiSeq platform. Additional PCR analyses were performed to identify the frequencies and host origin for each virus detected by HTS. Sequences more closely related to the Paramyxoviridae, Parvoviridae and Anelloviridae families were detected, as well as circular Rep-encoding single-stranded (CRESS) DNA viruses. CDV was found only in crab-eating foxes, whereas CPV-2 was found in both canid species; both viruses were closely related to sequences reported in domestic dogs from southern Brazil. Moreover, the present work reported the detection of canine bocavirus (CBoV) strains that were genetically divergent from CBoV-1 and 2 lineages. Finally, we also characterized CRESS DNA viruses and anelloviruses with marked diversity. The results of this study contribute to the body of knowledge regarding wild canid viruses that can potentially be shared with domestic canids or other species.

Studies of clinical symptoms of panleukopenia in cats in the Donetsk People’s Republic

Feline panleukopenia is a highly contagious viral disease of the members of the family Felidae caused by a DNA-virus of the family Parvoviridae. After infection, the virus is detected in saliva, nasal discharge, urine and feces; it is transmitted through excrements, water, food, and, according to some reports, by bloodsucking insects. The disease is characterized by gastrointestinal tract, central nervous system, hematopoietic tissue lesions. The paper describes the clinical signs of panleukopenia in cats in the territory of the Donetsk People’s Republic. Based on the records of a state-financed veterinary hospital and a charitable animal shelter located in the town of Yasinovataya, as well as those of private veterinary clinics and a veterinary office located in Donetsk, a classification of the clinical signs of the disease in pet and stray cats is suggested with the signs grouped according to their occurrence rate and by age groups. The paper provides evidence of feline panleukopenia occurrence in the territory of the Donetsk People’s Republic. In particular, the period from 2015 to 2018 was characterized by an increase in panleukopenia morbidity in stray animals; pet cats were also involved in the epidemic process. It was found that most of the clinical symptoms of panleukopenia were reported in cats of all age categories irrespective of their sex. Specific symptoms characteristic for different age groups were reported. It was found that panleukopenia morbidity rates for stray kittens aged 0–12 months were 1.8 times higher than those for pet kittens of the same age group. The disease was reported in adult pet cats 2.4 times less frequently than in stray cats. It is shown that the number of the disease cases in female cats is 1.5 times higher than in male ones. It is concluded that the violation of quarantine rules and insufficient vaccination coverage in cats are risk factors for the disease outbreak occurrence precipitating the multiple recurrent outbreaks of the disease.

Reorganizing the family Parvoviridae: a revised taxonomy independent of the canonical approach based on host association.

Parvoviridae, a diverse family of small single-stranded DNA viruses was established in 1975. It was divided into two subfamilies, Parvovirinae and Densovirinae, in 1993 to accommodate parvoviruses that infect vertebrate and invertebrate animals, respectively. This relatively straightforward segregation, using host association as the prime criterion for subfamily-level classification, has recently been challenged by the discovery of divergent, vertebrate-infecting parvoviruses, dubbed "chapparvoviruses", which have proven to be more closely related to viruses in certain Densovirinae genera than to members of the Parvovirinae. Viruses belonging to these genera, namely Brevi-, Hepan- and Penstyldensovirus, are responsible for the unmatched heterogeneity of the subfamily Densovirinae when compared to the Parvovirinae in matters of genome organization, protein sequence homology, and phylogeny. Another genus of Densovirinae, Ambidensovirus, has challenged traditional parvovirus classification, as it includes all newly discovered densoviruses with an ambisense genome organization, which introduces genus-level paraphyly. Lastly, current taxon definition and virus inclusion criteria have significantly limited the classification of certain long-discovered parvoviruses and impedes the classification of some potential family members discovered using high-throughput sequencing methods. Here, we present a new and updated system for parvovirus classification, which includes the introduction of a third subfamily, Hamaparvovirinae, resolves the paraphyly within genus Ambidensovirus, and introduces new genera and species into the subfamily Parvovirinae.These proposals were accepted by the ICTV in 2020 March.