Parvovirus DNA Research Articles

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.

For better or worse: crosstalk of parvovirus and host DNA damage response.

Parvoviruses are a group of non-enveloped DNA viruses that have a broad spectrum of natural infections, making them important in public health. NS1 is the largest and most complex non-structural protein in the parvovirus genome, which is indispensable in the life cycle of parvovirus and is closely related to viral replication, induction of host cell apoptosis, cycle arrest, DNA damage response (DDR), and other processes. Parvovirus activates and utilizes the DDR pathway to promote viral replication through NS1, thereby increasing pathogenicity to the host cells. Here, we review the latest progress of parvovirus in regulating host cell DDR during the parvovirus lifecycle and discuss the potential of cellular consequences of regulating the DDR pathway, targeting to provide the theoretical basis for further elucidation of the pathogenesis of parvovirus and development of new antiviral drugs.

Occurrence of Typical Domestic Animal Viruses in Wild Carnivorans: An Emerging Threat to the Conservation of Endangered Species

Wild species are susceptible to several typical domestic animal pathogens, and the increasingly close contact between these groups is a predictive factor for disease exposure. Some viruses are important and old-known, and others are emerging or reemerging for domestic carnivorans and have been identified as threats to the conservation of wild mammals. The purpose of the study was to investigate the occurrence of bocaparvoviruses (BoVs, Parvoviridae family, Parvovirinae subfamily, Bocaparvovirus genus), parvoviruses (Parvoviridae family, Parvovirinae subfamily, Protoparvovirus genus, Protoparvovirus carnivoran1), hepadnaviruses (Hepadnaviridae family), coronaviruses (Coronaviridae family, Orthocoronavirinae subfamily), paramyxoviruses (Paramyxoviridae family) and canine distemper virus (Orthoparamyxovirinae subfamily, Morbillivirus genus, Morbillivirus canis), poxviruses (Poxviridae family), feline herpesvirus (Orthoherpesviridae family, Alphaherpesvirinae subfamily, Varicellovirus genus, Varicellovirus felidalpha1), feline calicivirus (Caliciviridae family, Vesivirus genus, FCV), feline immunodeficiency virus (Retroviridae family, Orthoretrovirinae subfamily, Lentivirus genus, FIV), feline leukemia virus (Retroviridae family, Orthoretrovirinae subfamily, Gammaretrovirus genus, FeLV), and gammaherpesviruses (Orthoherpesviridae family, Gammaherpesvirinae subfamily) in wild carnivorans. A total of 30 biological samples from the families Canidae, Felidae, Mephitidae, Mustelidae, and Procyonidae were evaluated. All animals were victims of vehicular collisions in the state of Mato Grosso do Sul, Brazil. Canine parvovirus (CPV-2) DNA was detected in the spleen of a bush dog (Speothos venaticus), a jaguarundi (Puma yagouaroundi), and a jaguar (Panthera onca), FeLV proviral DNA was found in the spleen of an ocelot (Leopardus pardalis); while CDV RNA was detected in the liver of a jaguarundi. Phylogenetic analysis carried out with the partial sequence of the CPV-2 VP2 gene and the U3 (LTR) gag region of FeLV showed 100% identity with strains obtained from domestic dogs and cats, respectively. The approximation between wild and domestic animals favors the transmission of pathogens, especially between phylogenetically close species, such as members of the Canidae and Felidae families. Identification of the DNA and RNA of potentially fatal viruses such as CPV-2, FeLV, and CDV in four wilds endangered to extinction and understudied species contributes to our understanding of the pathogens circulating in this free-ranging and vulnerable population.

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.

Screening of West Nile Virus, Herpesvirus, and Parvovirus in Rattus spp. in Klang Valley, Malaysia

Free-roaming and scavenging lifestyles of Rattus spp. in densely populated urban areas expose them to multiple pathogens that facilitate the transmission of infection to the human population more rapidly, raising public health concerns. There is limited information on the status of rat susceptibility to virus infection, particularly West Nile virus (WNV), herpesvirus, and parvovirus, to prepare for emerging zoonosis. A total of 23 (n = 23) blood samples collected from Rattus spp. in the wet market areas of Klang Valley, Malaysia, were subjected to molecular assay using a one-step reverse transcription-polymerase chain reaction (RT-PCR) to detect the highly conserved region of the WNV capsid and pre-membrane protein via nested polymerase chain reaction (PCR) assay targeting highly conserved amino acid motifs within the herpesviral DNA-directed DNA polymerase gene (DPOL) and polymerase chain reaction (PCR) assay targeting the parvovirus non-structural (NS) protein. As a result, 4 out of 23 (17.39%) rats were positive for herpesvirus DNA, but none were positive for WNV RNA and parvovirus DNA. The positive PCR amplicons of herpesvirus DNA were subjected to partial DNA sequencing analysis, 100% identical to Acomys herpesvirus SVMS 226,222 from Betaherpesvirinae, which is highly suggestive of rat cytomegalovirus (RCMV). This study has successfully demonstrated the presence of RCMV from Rattus spp. in the Klang Valley. The RCMV potentially crosses species barriers and establishes infection, raising public health concerns. The non-viraemic state of WNV or parvovirus infection, low sample size, and limited niche distribution emphasise the need for the expansion of this study in the future.

Low Intrahost and Interhost Genetic Diversity of Carnivore Protoparvovirus 1 in Domestic Cats during a Feline Panleukopenia Outbreak.

Feline panleukopenia (FPL), a highly contagious and frequently fatal disease of cats, is caused by Feline parvovirus (FPV) and Canine parvovirus (CPV). We characterised the diversity of these Carnivore protoparvovirus 1 variants in 18 faecal samples collected from domestic cats with FPL during an outbreak, using targeted parvoviral DNA metagenomics to a mean depth of >10,000 × coverage per site. All samples comprised FPV alone. Compared with the reference FPV genome, isolated in 1967, 44 mutations were detected. Ten of these were nonsynonymous, including 9 in nonstructural genes and one in VP1/VP2 (Val232Ile), which was the only one to exhibit interhost diversity, being present in five sequences. There were five other polymorphic nucleotide positions, all with synonymous mutations. Intrahost diversity at all polymorphic positions was low, with subconsensus variant frequencies (SVF) of <1% except for two positions (2108 and 3208) in two samples with SVF of 1.1–1.3%. Intrahost nucleotide diversity was measured across the whole genome (0.7–1.5%) and for each gene and was highest in the NS2 gene of four samples (1.2–1.9%). Overall, intrahost viral genetic diversity was limited and most mutations observed were synonymous, indicative of a low background mutation rate and strong selective constraints.

Prevalence, Cell Tropism, and Clinical Impact of Human Parvovirus Persistence in Adenomatous, Cancerous, Inflamed, and Healthy Intestinal Mucosa.

Parvoviruses are single-stranded DNA viruses, infecting many animals from insects to humans. Human parvovirus B19 (B19V) causes erythema infectiosum, arthropathy, anemia, and fetal death, and human bocavirus (HBoV) 1 causes respiratory tract infections, while HBoV2-4 are enteric. Parvoviral genomes can persist in diverse non-permissive tissues after acute infection, but the host-cell tropism and the impact of their tissue persistence are poorly studied. We searched for parvoviral DNA in a total of 427 intestinal biopsy specimens, as paired disease-affected and healthy mucosa, obtained from 130 patients with malignancy, ulcerative colitis (UC), or adenomas, and in similar intestinal segments from 55 healthy subjects. Only three (1.6%) individuals exhibited intestinal HBoV DNA (one each of HBoV1, 2, and 3). Conversely, B19V DNA persisted frequently in the intestine, with 50, 47, 31, and 27% detection rates in the patients with malignancy, UC, or adenomas, and in the healthy subjects, respectively. Intra-individually, B19V DNA persisted significantly more often in the healthy intestinal segments than in the inflamed colons of UC patients. The highest loads of B19V DNA were seen in the ileum and colon specimens of two healthy individuals. With dual-RNAscope in situ hybridization and immunohistochemistry assays, we located the B19V persistence sites of these intestines in mucosal B cells of lymphoid follicles and vascular endothelial cells. Viral messenger RNA transcription remained, however, undetected. RNA sequencing (RNA-seq) identified 272 differentially expressed cellular genes between B19V DNA-positive and -negative healthy ileum biopsy specimens. Pathway enrichment analysis revealed that B19V persistence activated the intestinal cell viability and inhibited apoptosis. Lifelong B19V DNA persistence thus modulates host gene expression, which may lead to clinical outcomes.

Why serology just is not enough: Strategic parvovirus risk assessment using a novel qPCR assay.

Health monitoring of laboratory rodents not only improves animal health but also enhances the validity of animal experiments. In particular, infections of laboratory animals with murine parvoviruses influence biomedical research data. Despite strict barrier housing, prevalence remains high in animal facilities, leading to increased risk of parvovirus introduction after the import of contaminated mice. Unfortunately, hygienic rederivation can be challenging, since gametes often contain residual virus material. Consequently, the process has to be closely monitored with highly sensitive diagnostic methods to verify parvovirus decontamination of the rederived progeny. However, diagnostic sensitivity of traditional methods is often low and requires testing of large animal cohorts. Therefore, we aimed to develop a powerful quantitative real-time polymerase chain reaction (qPCR) assay for the fast and reliable detection of murine parvoviruses in different sample materials. We validated the assay within an infection experiment and systematically analysed various animal-derived and environmental sample materials. We further developed a strategic risk assessment procedure for parvovirus monitoring after embryo transfer. Our novel qPCR assay reliably detected parvovirus DNA in a broad variety of sample materials, with environmental samples dominating in the acute phase of infection, whereas animal-derived samples were more suitable to detect low virus loads in the chronic phase. Here, the assay served as a highly sensitive screening method for parvovirus contamination in mouse colonies, requiring significantly lower sample sizes than traditional methods like conventional PCR and serology. Thus, the use of our novel qPCR assay substantially improves parvovirus diagnostics, enhancing research validity according to the 6Rs.

Articles of Significant Interest in This Issue

The terminal hairpin sequences are thought to be indispensable for parvoviral DNA replication. Shen et al. (e01108-21) showed that transfection of the human bocavirus (HBoV1) duplex genome, which retains a minimal replication origin at the right end (OriR) but without the right-end hairpin sequence, produced virions in HEK293 cells. An 18-nt sequence (nt 5403 to 5420) beyond the OriR was required to allow the progeny virions to be infectious in polarized human airway epithelia. This study suggests that the leading strand of the HBoV1 duplex genome can initiate strand displacement without hairpin transfer, which is hairpin-independent parvoviral DNA replication.

A Novel Amperometric Genosensor for Rapid Detection of Canine Parvovirus in Feces.

A highly sensitive novel amperometric genosensor has been developed for rapid detection of canine parvovirus (CPV) DNA in fecal swabs of naturally infected dogs. The genosensor is based on a single stranded 5°-thiolated (SH) DNA probe complementary to VP1/VP2 gene of canine parvo vaccine strain, immobilized covalently on a polycrystalline gold (Au) electrode. The genosensor has been characterized by scanning electron microscopy (SEM), Fourier Transform Infra-Red Spectroscopy (FTIR), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectra (EIS). The ssDNA-SH/Au electrode was hybridized with single stranded target DNA (ss T-DNA) in the sample. This hybridization was detected by reduction in current, generated by interaction of methylene blue (MB) with free guanine of ssDNA. The current response of genosensor was determined by CV, DPV and EIS. The sensor detected single stranded genomic DNA (ss g-DNA) isolated from vaccine strain of CPV in the range, 1.0-12.0 ng/μl at 25 °C for 10 min. Subsequently, the genobiosensor was applied for detection of CPV viral DNA in fecal swabs of naturally infected dogs. The limit of detection (LOD) of the sensor was 1.0 ng/μl of fecal viral DNA. To the best of our knowledge, this is the first report on development and application of amperometric biosensor for rapid, sensitive, specific point of care detection of viral DNA of CPV in feces.

Persistence of Human Bocavirus 1 in Tonsillar Germinal Centers and Antibody-Dependent Enhancement of Infection.

Human bocavirus 1 (HBoV1), a nonenveloped single-stranded DNA parvovirus, causes mild to life-threatening respiratory tract infections, acute otitis media, and encephalitis in young children. HBoV1 often persists in nasopharyngeal secretions for months, hampering diagnosis. It has also been shown to persist in pediatric palatine and adenoid tonsils, which suggests that lymphoid organs are reservoirs for virus spread; however, the tissue site and host cells remain unknown. Our aim was to determine, in healthy nonviremic children with preexisting HBoV1 immunity, the adenotonsillar persistence site(s), host cell types, and virus activity. We discovered that HBoV1 DNA persists in lymphoid germinal centers (GCs), but not in the corresponding tonsillar epithelium, and that the cell types harboring the virus are mainly naive, activated, and memory B cells and monocytes. Both viral DNA strands and both sides of the genome were detected, as well as infrequent mRNA. Moreover, we showed, in B-cell and monocyte cultures and ex vivo tonsillar B cells, that the cellular uptake of HBoV1 occurs via the Fc receptor (FcγRII) through antibody-dependent enhancement (ADE). This resulted in viral mRNA transcription, known to occur exclusively from double-stranded DNA in the nucleus, however, with no detectable productive replication. Confocal imaging with fluorescent virus-like particles moreover disclosed endocytosis. To which extent the active HBoV1 GC persistence has a role in chronic inflammation or B-cell maturation disturbances, and whether the virus can be reactivated, will be interesting topics for forthcoming studies.IMPORTANCE Human bocavirus 1 (HBoV1), a common pediatric respiratory pathogen, can persist in airway secretions for months hampering diagnosis. It also persists in tonsils, providing potential reservoirs for airway shedding, with the exact location, host cell types, and virus activity unknown. Our study provides new insights into tonsillar HBoV1 persistence. We observed HBoV1 persistence exclusively in germinal centers where immune maturation occurs, and the main host cells were B cells and monocytes. In cultured cell lines and primary tonsillar B cells, we showed the virus uptake to be significantly enhanced by HBoV1-specific antibodies, mediated by the cellular IgG receptor, leading to viral mRNA synthesis, but without detectable productive replication. Possible implications of such active viral persistence could be tonsillar inflammation, disturbances in immune maturation, reactivation, or cell death with release of virus DNA, explaining the long-lasting HBoV1 airway shedding.

Парвовирусная инфекция у детей и беременных

Parvovirus (PV) is a widespread infection, despite the fact that this pathogen was discovered only recently. The therapeutic effect of PV, in particular its oncolytic activity, is being actively studied now. Notably, PVs causing infections in animals, such as rat PV H-1, caninae PV, and rodent protoparvovirus (minute virus of mice) suppress oncogenesis in these animals. There is an ex vivo evidence of rat glioblastoma and gliosarcoma sensitivity to PV. The affinity of PV B19 to P-antigen located primarily on the membranes of erythroid cells is crucial for the disease pathogenesis. The teratogenic effect of PV B19 is associated with its ability to infect placental cells (P-antigen is present on the cells of chorionic villi and surface of the trophoblast). PV infection can be acquired or congenital, typical or atypical. The outcome of intrauterine infection with PV B19 largely depends on the gestation age when the infection occurred. Women infected during the second trimester are at higher risk of vertical transmission and severe intrauterine pathology with a poor outcome than those infected during the third trimester. Constant contact with young children significantly increases the risk of PV B19 infection among pregnant women with no immunity to this virus. Serum is the most convenient biomaterial for detecting both PV DNA and virus-specific antibodies. One test for anti-PV IgG using enzyme-linked immunosorbent assay is sufficient to determine the immune status of a patient. Polymerase chain reaction with amniotic fluid is used to diagnose intrauterine infection with PV B19. Blood components and products should be checked for PV B19. High frequency of PV B19 detection in the blood of donors necessitates the development of special measures aimed at prevention of virus transmission. Key words: pregnant women, children, parvovirus B19, parvovirus infection

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.

Molecular Design and Production of AAV Viral Vectors for Gene Therapy.

Adeno-associated virus (AAV) is a helper-dependent single-stranded DNA parvovirus. Over the years, AAV has become the vector of choice in the gene therapy field due to its safety profile and low immunogenicity. With a carrying capacity of 4.2kbp, these vectors have demonstrated their clinical value, especially in the field of ophthalmology. Herein we describe methods for the molecular design and packaging of AAV viral vectors. These methods apply to the design of single-stranded or self-complementary AAV vectors.

Results of a study of parvovirus B19 (Parvoviridae, Parvovirinae, Erythroparvovirus, Primate erythroparvovirus 1) prevalence and circulation activity in socially significant categories of the population

Currently, along with the increasing need of medical organizations for blood preparations, algorithms for laboratory testing of blood donors are not available for all infections with hemo-contact mechanism of transmission. A representative example is infection caused by parvovirus В19. Purpose of the study. The article presents the results of the original study, the purpose of which was to study the prevalence of antibodies to parvovirus B19 and the activity of the circulation of this virus in socially important categories of the population. Material and methods. The materials of the study were blood samples from blood donors of Saint Petersburg, as well as parvovirus В19 sequences isolated from DNA-positive plasma samples. Results and discussion. According to the results of the laboratory examination, a high proportion of carriers of virus-specific IgG antibodies was found in studied group of donors, which confirms the previous infection of parvovirus B19 in them and illustrates the high prevalence of infection in this socially significant group. Based on the results of the blood preparations testing, the presence of parvovirus DNA В19 in a significant number of samples was determined by polymerase chain reaction method. This indicates an current parvovirus infection in the examined donors and points to a high epidemiological risk of the blood products obtained from them. Sequencing and phylogenetic analysis of a fragment of the VP1 gene demonstrated that the studied isolates belonged to А1 genotype and its subtype 1А2, which correlates with the genotypes of parvovirus В19 circulating in the European Union and Asia. In addition, two previously unknown В19 parvovirus isolates were isolated, the nucleotide sequences of which were deposited into the international GenBank database. Conclusion. Based on the results of the study, it is justified to include testing of blood samples for markers of В19 parvovirus infection in existing algorithms of laboratory examination of donors, which will ensure prevention of hemo-contact infection of blood recipients with parvovirus В19.

Parvovirus B19 infection in sickle cell disease: An analysis from the Centers for Disease Control haemoglobinopathy blood surveillance project.

In the multicentre Haemoglobinopathy Blood Surveillance Project, to evaluate the seroprevalence of parvovirus B19 and DNA viral load in sickle cell disease (SCD). Although the epidemiology of parvovirus B19 seropositivity in SCD has been well documented, there are few studies that have assessed possible persistent parvovirus DNAemia and associated risk factors including blood transfusion. A qualitative analysis of parvovirus B19 serology using ELISA and quantitative parvovirus B19 DNA by RT-PCR was performed in patients with SCD. Of 322 patients, 113 (35%) were parvovirus IgG positive and 119 (37%) were IgM positive at enrolment. The prevalence of IgG positivity increased with age. 71/322 (22%) were parvovirus DNA positive at enrolment with a mean viral load of 15 227 ± 55 227 SD. (range 72-329 238 IU/mL). Patients who were positive for parvovirus B19 DNA received a significantly higher red blood cell transfusion volume in the prior year compared to patients who were negative (mean RBC volume = 8310 mL vs 5435 mL, respectively; P = .0073). Seventy-seven patients had follow-up testing approximately 1 year after enrolment and 11/28 (39%) patients had persistently positive IgM. Further studies are needed to better understand the natural history of parvovirus B19 infection in SCD especially in relation to RBC transfusion as a risk factor, as well as disease outcome and severity.

Elaboration of Triplex PCR for Detection of Selected Viral Infections in Waterfowl.

IntroductionViral infections are the greatest threat to waterfowl and cause significant economic losses. Diagnosis and differentiation of three goose viruses is difficult in the field and often requires laboratory confirmation. Therefore, the aim of the study was to develop a triplex PCR and optimise its parameters for simultaneous detection of DNA of goose parvovirus (GPV), goose polyomavirus (GHPV), and goose circovirus (GoCV).Material and MethodsThe DNA of viruses isolated from field cases from the National Veterinary Research Institute’s own collection was used for the study. The primer attachment temperature, the number of reaction cycles, and the Taq DNA polymerase and Mg2+ concentrations were optimised. The sensitivity and specificity of this triplex PCR was also determined.ResultsBased on the obtained results, triplex PCR parameters were optimised for simultaneous detection of DNA of GPV, GHPV, and GoCV in one sample. The following PCR products of the expected size were obtained: GPV DNA of 806 bp, GoCV DNA of 571 bp, and GHPV DNA of 180 bp.ConclusionThe developed triplex PCR method proved to be useful for simultaneous detection of infections with three waterfowl viruses and will be used in relevant laboratory diagnostics.

Genetic characterization of Carnivore Parvoviruses in Spanish wildlife reveals domestic dog and cat-related sequences.

The impact of carnivore parvovirus infection on wild populations is not yet understood; disease signs are mainly developed in pups and assessing the health of litters in wild carnivores has big limitations. This study aims to shed light on the virus dynamics among wild carnivores thanks to the analysis of 213 samples collected between 1994 and 2013 in wild ecosystems from Spain. We determined the presence of carnivore parvovirus DNA by real-time PCR and sequenced the vp2 gen from 22 positive samples to characterize the strains and to perform phylogenetic analysis. The presence of carnivore parvovirus DNA was confirmed in 18% of the samples, with a higher prevalence detected in wolves (Canis lupus signatus, 70%). Fourteen sequences belonging to nine wolves, three Eurasian badgers (Meles meles), a common genet (Genetta genetta) and a European wildcat (Felis silvestris) were classified as canine parvovirus 2c (CPV-2c); five sequences from three wolves, a red fox (Vulpes vulpes) and a stone marten (Martes foina) as CPV-2b; and three sequences from a badger, a genet and a stone marten as feline parvovirus (FPV). This was the first report of a wildcat infected with a canine strain. Sequences described in this study were identical or very close related to others previously found in domestic carnivores from distant countries, suggesting that cross-species transmission takes place and that the parvovirus epidemiology in Spain, as elsewhere, could be influenced by global factors.

Faecal shedding of parvovirus deoxyribonucleic acid following modified live feline panleucopenia virus vaccination in healthy cats.

Positive canine parvovirus (CPV) faecal test results have been reported in dogs after modified live virus (MLV) vaccination. Thus, the aim was to investigate feline panleucopenia virus (FPV) shedding in recently vaccinated, adult, clinically healthy cats and to assess related factors. Forty cats were vaccinated with an FPV MLV vaccine. Faeces of cats were tested for presence of parvovirus DNA on days 7, 14, 21 and 28 by quantitative real-time PCR; DNA-positive samples were subjected to partial VP2 gene sequencing. Virus isolation was performed whenever sufficient amounts of faeces were available. Serum antibody titres were measured by haemagglutination inhibition on days 0, 7 and 28. Overall, 30.0 per cent (12/40; 95% CI 18.0 to 45.6) of cats shed parvovirus DNA. Sequencing revealed FPV vaccine virus DNA in three cats, FPV field virus DNA in four cats and CPV field virus DNA in one cat. Shedding was significantly associated with lack of prevaccination antibody titres (40) (P=0.016; OR: 6.44; 95% CI 1.44 to 28.89) and with postvaccination titre increases (fourfold) (P=0.029; OR: 5.00; 95% CI 1.17 to 21.39). Shedding of field or vaccine virus DNA seems to be common in healthy cats which can be a concern in shelters and catteries. Diagnostic tools should be developed to facilitate differentiation of vaccine and field virus shedding.

Carnivore Parvovirus Ecology in the Serengeti Ecosystem: Vaccine Strains Circulating and New Host Species Identified.

Carnivore parvoviruses infect wild and domestic carnivores, and cross-species transmission is believed to occur. However, viral dynamics are not well understood, nor are the consequences for wild carnivore populations of the introduction of new strains into wild ecosystems. To clarify the ecology of these viruses in a multihost system such as the Serengeti ecosystem and identify potential threats for wildlife conservation, we analyzed, through real-time PCR, 152 samples belonging to 14 wild carnivore species and 62 samples from healthy domestic dogs. We detected parvovirus DNA in several wildlife tissues. Of the wild carnivore and domestic dog samples tested, 13% and 43%, respectively, were positive for carnivore parvovirus infection, but little evidence of transmission between the wild and domestic carnivores was detected. Instead, we describe two different epidemiological scenarios with separate routes of transmission: first, an endemic feline parvovirus (FPV) route of transmission maintained by wild carnivores inside the Serengeti National Park (SNP) and, second, a canine parvovirus (CPV) route of transmission among domestic dogs living around the periphery of the SNP. Twelve FPV sequences were characterized; new host-virus associations involving wild dogs, jackals, and hyenas were discovered; and our results suggest that mutations in the fragment of the vp2 gene were not required for infection of different carnivore species. In domestic dogs, 6 sequences belonged to the CPV-2a strain, while 11 belonged to the CPV-2 vaccine-derived strain. This is the first description of a vaccine-derived parvovirus strain being transmitted naturally.IMPORTANCE Carnivore parvoviruses are widespread among wild and domestic carnivores, which are vulnerable to severe disease under certain circumstances. This study furthers the understanding of carnivore parvovirus epidemiology, suggesting that feline parvoviruses are endemic in wild carnivores in the Serengeti National Park (SNP), with new host species identified, and that canine parvoviruses are present in the dog population living around the SNP. Little evidence of transmission of canine parvoviruses into wild carnivore species was found; however, the detection of vaccine-derived virus (described here for the first time to be circulating naturally in domestic dogs) highlights the importance of performing epidemiological research in the region.