Avian Polyomavirus Among Psittacine Birds in Iran: Molecular Detection Rate and Associated Risk Factors.

Avian polyomavirus (APV) infection causes various health problems in psittacine species, including death. The present study was conducted to investigate the prevalence of APV among psittacine birds in Iran. We also aimed to evaluate the impact of age, sex, species, season, and origin of the birds on the prevalence of APV. This study investigated the presence of APV among 1050 individual birds from 7 psittacine species over a 1-year period in Iran, namely, green-cheeked parakeets (Pyrrhura molinae), rosy-faced lovebirds (Agapornis roseicollis), monk parakeets (Myiopsitta monachus), sun conures (Aratinga solstitialis), Senegal parrots (Poicephalus senegalus), cockatiels (Nymphicus hollandicus), and grey parrots (Psittacus erithacus). The overall prevalence of APV in all studied species was 25% (263/1050, 95% confidence interval [CI]: 22.5-27.8). Results of the study showed that age and the season of the year were 2 important determinant factors in the prevalence of APV in psittacine birds. Young psittacine birds <6 months old were 2.94 (95% CI: 1.19-7.27) times more likely to be infected with APV than birds >1 year old, and there was a significant interaction between season and species in the multivariate analysis. In the winter season, rosy-faced lovebirds and green-cheeked parakeets were 15.6 (95% CI: 4.20-57.95) and 4.76 (95% CI: 1.4-16.21) times more likely to be infected with APV than in other seasons, respectively. This is the first report on the detection rate of APV in psittacine birds in Iran.

Hamster polyomavirus-associated T-cell lymphomas in Syrian hamsters (Mesocricetus auratus).

Hamster polyomavirus (HaPyV) infection has been associated with lymphomas in Syrian hamsters. In the present study, 14 cases of lymphoma in pet Syrian hamsters were pathologically examined and the involvement of HaPyV was investigated. Among 14 cases, 11 were abdominal and 3 were cutaneous lymphomas. The average ages of hamsters with abdominal lymphoma and cutaneous lymphoma were 7 months (range: 4-12 months) and 14 months (range: 6-23 months), respectively. Histologically, abdominal lymphomas were characterized by the diffuse growth of tumor cells with intermediate or large nuclei, low mitotic rates, the presence of tingible body macrophages, and the T-cell immunophenotype. Furthermore, 4/11 abdominal lymphomas were immunopositive for T-cell intracellular antigen-1, suggesting cytotoxic T-cell lymphomas. Cutaneous lymphomas were diagnosed as nonepitheliotropic T-cell lymphoma. Polymerase chain reaction (PCR) detected HaPyV DNA in 12/14 samples, and a sequence analysis of PCR amplicons confirmed >99% nucleotide identity to the published HaPyV sequences. In situ hybridization (ISH) for HaPyV DNA resulted in diffuse nuclear signals within tumor cells in 10/14 cases. Consistent with previous findings, all HaPyV-associated lymphomas were observed in the abdominal cavity of young hamsters. Polymerase chain reaction and ISH were useful for identifying the involvement of HaPyV in lymphomas, and ISH results indicated the presence of episomal HaPyV in neoplastic lymphocytes. The present study suggests that HaPyV infection is highly involved in abdominal lymphomas in young pet Syrian hamsters in Japan and provides diagnostic information on HaPyV-associated lymphoma.

Pathogenicity of Avian Polyomaviruses and Prospect of Vaccine Development.

Polyomaviruses are nonenveloped icosahedral viruses with a double-stranded circular DNA containing approximately 5000 bp and 5-6 open reading frames. In contrast to mammalian polyomaviruses (MPVs), avian polyomaviruses (APVs) exhibit high lethality and multipathogenicity, causing severe infections in birds without oncogenicity. APVs are classified into 10 major species: Adélie penguin polyomavirus, budgerigar fledgling disease virus, butcherbird polyomavirus, canary polyomavirus, cormorant polyomavirus, crow polyomavirus, Erythrura gouldiae polyomavirus, finch polyomavirus, goose hemorrhagic polyomavirus, and Hungarian finch polyomavirus under the genus Gammapolyomavirus. This paper briefly reviews the genomic structure and pathogenicity of the 10 species of APV and some of their differences in terms of virulence from MPVs. Each gene's genomic size, number of amino acid residues encoding each gene, and key biologic functions are discussed. The rationale for APV classification from the Polyomavirdae family and phylogenetic analyses among the 10 APVs are also discussed. The clinical symptoms in birds caused by APV infection are summarized. Finally, the strategies for developing an effective vaccine containing essential epitopes for preventing virus infection in birds are discussed. We hope that more effective and safe vaccines with diverse protection will be developed in the future to solve or alleviate the problems of viral infection.

Viral gene expression profile of goose haemorrhagic polyomavirus in susceptible primary cells.

Routine culturing of goose haemorrhagic polyomavirus (GHPV) is cumbersome, and limited data are available about its replication and gene expression profile. In this study, goose embryo fibroblast cells were infected with GHPV for temporal measurement of the viral genome copy number and mRNA levels with quantitative PCR. Accumulation of small and large tumour antigen-encoding mRNAs was detected as early as 9 hours post-infection (hpi), while high level expression of the capsid protein encoding VP1-VP3, and ORF-X mRNAs was first detected at 24 hpi. Elevation of GHPV genome copy number was noted at 48 hpi. The results indicate that the gene expression profile of GHPV is similar to that described for mammalian polyomaviruses.RESEARCH HIGHLIGHTS GHPV was propagated in culture of primary goose embryo fibroblast cells.The transcription commenced before the onset of viral DNA replication.The transcription patterns of GHPV and mammalian polyomaviruses were comparable.

A polyomavirus detected in American black bear (Ursus americanus).

Polyomaviruses are ancient DNA viruses that infect several species of animals. While recognition of the family Polyomaviridae has grown rapidly, there are few studies that consider their potential association with disease. Carnivora are a diverse and widespread order affected by polyomaviruses (PyVs) that have co-evolved with their hosts for millions of years. PyVs have been identified in sea lions, raccoons, badgers, Weddell seals, and dogs. We have discovered a polyomavirus, tentatively named "Ursus americanus polyomavirus 1" (UaPyV1) in black bears (Ursus americanus). UaPyV1 was detectable in various tissues of six out of seven bears submitted for necropsy. Based on viral phylogenetic clustering and detection of the virus in multiple individuals, we suggest that black bears are the natural hosts for UaPyV1. In this albeit small group, there is no clear relationship between UaPyV1 infection and any specific disease.

Identification of African Elephant Polyomavirus in wild elephants and the creation of a vector expressing its viral tumor antigens to transform elephant primary cells.

Wild elephant populations are declining rapidly due to rampant killing for ivory and body parts, range fragmentation, and human-elephant conflict. Wild and captive elephants are further impacted by viruses, including highly pathogenic elephant endotheliotropic herpesviruses. Moreover, while the rich genetic diversity of the ancient elephant lineage is disappearing, elephants, with their low incidence of cancer, have emerged as a surprising resource in human cancer research for understanding the intrinsic cellular response to DNA damage. However, studies on cellular resistance to transformation and herpesvirus reproduction have been severely limited, in part due to the lack of established elephant cell lines to enable in vitro experiments. This report describes creation of a recombinant plasmid, pAelPyV-1-Tag, derived from a wild isolate of African Elephant Polyomavirus (AelPyV-1), that can be used to create immortalized lines of elephant cells. This isolate was extracted from a trunk nodule biopsy isolated from a wild African elephant, Loxodonta africana, in Botswana. The AelPyV-1 genome contains open-reading frames encoding the canonical large (LTag) and small (STag) tumor antigens. We cloned the entire early region spanning the LTag and overlapping STag genes from this isolate into a high-copy vector to construct a recombinant plasmid, pAelPyV-1-Tag, which effectively transformed primary elephant endothelial cells. We expect that the potential of this reagent to transform elephant primary cells will, at a minimum, facilitate study of elephant-specific herpesviruses.

Genomic evolution of avian polyomaviruses with a focus on budgerigar fledgling disease virus.

Gammapolyomaviruses may cause serious inflammatory diseases in a broad range of avian hosts. In this study we investigated genomic evolution of and selection constraint acting on avian polyomaviruses (APyVs). Our analyses suggested that goose haemorrhagic polyomavirus (GHPV) evolves more slowly (3.03 × 10-5 s/s/y mean evolutionary rate) than budgerigar fledgling disease virus (BFDV), finch polyomavirus (FPyV) and canary polyomavirus (CaPyV) (1.39 × 10-4 s/s/y, 2.63 × 10-4 s/s/y and 1.41 × 10-4 s/s/y mean evolutionary rate, respectively). In general, purifying selection seems to act on the protein coding regions of APyV genomes, although positive Darwinian selection was also predicted in a few positions (e.g., in the large tumor antigen coding region of BFDV and GHPV and in the capsid protein sequences of BFDV). The importance of these aa changes remains elusive. Overall, a better understanding of adaptive changes in the genome of APyVs requires additional data from various incidental hosts and reservoir species.

Comparative In Vitro and In Vivo Studies on Feline, Canine, and Human Merkel Cell Carcinoma.

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor, and most human MCC cases are infected by Merkel cell polyomavirus (MCPyV). However, the underlying pathogeneses of MCC in animals remain unclear. In the present study, newly established cell lines from feline and canine MCC, a MCPyV-positive human MCC cell line, and MCC tissues from 25 cats and 1 dog were examined and compared pathologically. Feline and canine MCCs were composed of tumor cells arranged in trabeculae and solid packets. Twenty out of 25 feline MCC cases (80%) had other proliferative cutaneous lesions, such as carcinoma in situ and squamous cell carcinoma. Among the 25 feline MCC cases, tumor cells were immunopositive for cytokeratins (CKs), including CK5/6 (4/25 cases, 16%), CK7 (5, 20%), CK18 (25, 100%), CK19 (20, 80%), and CK20 (20, 80%). The tumor cells of feline MCC were also immunopositive for synaptophysin (24/25, 96%) and CD56 (22/25, 88%). The tumor cells of canine MCC were immunopositive for CK18, CK19, CK20, and synaptophysin. Cultured feline and canine MCC cells grew in adherent monolayers and exhibited diffuse cytoplasmic immunoreactivity for CKs, whereas human MCC cells grew in suspension and exhibited dot-like cytoplasmic immunoreactivity for CKs. Differences in the distribution of CKs between human and animal MCC may be attributed to cell adhesion propensities. MCPyV genes and antigen were not detected in feline or canine MCC, suggesting a different etiology from human MCC.

Localization of goose haemorrhagic polyomavirus in naturally infected geese using in situ hybridization.

Goose haemorrhagic polyomavirus (GHPV) is the aetiological agent of haemorrhagic nephritis enteritis of geese (HNEG), a fatal disease that impacts geese and has been recorded only in Europe. The present study describes the first clinical cases of HNEG in Taiwan and the phylogenesis of Taiwanese GHPV, and it elucidates the pathogenesis of GHPV infection using in situ hybridization (ISH). The genomes of Taiwanese GHPV were highly similar to the previously reported strains. The diseased geese showed various degrees of vascular damage, especially in the digestive tract. The affected geese in the early stage showed transmural haemorrhagic enteritis in the intestine. In the middle to late stages, the most obvious lesion was hypoxic necrosis of renal tubules around intralobular central veins. Mineralization deposited in the kidney and systemic gout were also found. ISH revealed GHPV DNA in the vascular endothelial cells throughout the body, but not in the parenchymal cells of organs. Accordingly, the pathogenesis of GHPV infection was consistent with viral tropism in the endothelial cells. Specific attack of vascular endothelium by GHPV resulted in endothelial cell necrosis and subsequent increases of blood vessel permeability, as well as secondary circulation disorders, such as oedema, haemorrhage, and ischaemic necrosis in the adjacent parenchyma. RESEARCH HIGHLIGHTS Cell tropism of GHPV is determined by in situ hybridization. The tropism results in vascular dysfunction and subsequent pathobiology. Haemorrhagic nephritis and enteritis of geese described outside Europe for the first time.

Molecular epidemiology and phylodynamics of goose haemorrhagic polyomavirus.

Goose haemorrhagic polyomavirus (GHPV, or Anser anser polyomavirus 1) is a small dsDNA virus of the Polyomaviridae family. The virus infects the internal organs causing haemorrhagic nephritis and enteritis of geese that may be fatal for goslings. In this study, GHPV positivity was examined in goose and duck samples collected in Hungary between 2005 and 2019. In this period, 384 of the investigated 1,111 specimens were diagnosed as GHPV-positive by PCR assay. Twenty-two GHPV genomes were sequenced and subjected to phylogenetic and evolutionary analysis. Based on the sequence data, the mean evolutionary rates were estimated 6.57 × 10-6 -5.82 × 10-5  s/s/y for both GHPV complete genomes and individual genes, with negative selection acting on each gene. When GHPV VP1 sequences originating from wild birds were also included in the analyses, the nt and aa mutations inflated the substitution rate to 1.54 × 10-4  s/s/y that may imply adaptation of the virus to novel host species. Our data suggested the co-circulation of various GHPV strains in Hungarian goose farms; the source of these may be persistently infected domesticated or migratory wild birds. Detection and characterization of GHPV in wild birds and domestic waterfowls may help to elaborate new strategies for more effective disease control and prevention.

Monitoring of free-ranging and captive Psittacula populations in Western Europe for avian bornaviruses, circoviruses and polyomaviruses.

Avian pathogens such as bornaviruses, circoviruses and polyomaviruses are widely distributed in captive collections of psittacine birds worldwide and can cause fatal diseases. In contrast, only little is known about their presence in free-ranging psittacines and their impact on these populations. Rose-ringed parakeets (Psittacula krameri) and Alexandrine parakeets (Psittacula eupatria) are non-native to Europe, but have established stable populations in parts of Western Europe. From 2012-2017, we surveyed free-ranging populations in Germany and France as well as captive Psittacula individuals from Germany and Spain for avian bornavirus, circovirus and polyomavirus infections. Samples from two out of 469 tested free-ranging birds (0.4%; 95% confidence interval [CI-95]: 0.1-1.5%) were positive for beak and feather disease virus (BeFDV), whereas avian bornaviruses and polyomaviruses were not detected in the free-ranging populations. In contrast, avian bornaviruses and polyomaviruses, but not circoviruses were detected in captive populations. Parrot bornavirus 4 (PaBV-4) infection was detected by RT-PCR in four out of 210 captive parakeets (1.9%; CI-95: 0.7-4.8%) from four different holdings in Germany and Spain and confirmed by detection of bornavirus-reactive antibodies in two of these birds. Three out of 160 tested birds (1.9%; CI-95: 0.5-5.4%) possessed serum antibodies directed against budgerigar fledgling disease virus (BuFDV). PaBV-4 and BuFDV were also detected in several psittacines of a mixed holding in Germany, which had been in contact with free-ranging parakeets. Our results demonstrate that Psittacula parakeets are susceptible to common psittacine pathogens and their populations in Western Europe are exposed to these viruses. Nevertheless, the prevalence of avian bornaviruses, circoviruses and polyomaviruses in those populations is very low.RESEARCH HIGHLIGHTS Psittacula parakeets are susceptible to bornavirus, circovirus and polyomavirus infection.Introduced Psittacula populations in Europe have been exposed to these viruses.Nevertheless, they may be absent or present at only low levels in free-ranging Psittacula populations.Free-ranging populations in Europe pose a minor threat of transmitting these viruses to captive Psittaciformes.

Codon usage patterns of LT-Ag genes in polyomaviruses from different host species.

BACKGROUND: Polyomaviruses (PyVs) have a wide range of hosts, from humans to fish, and their effects on hosts vary. The differences in the infection characteristics of PyV with respect to the host are assumed to be influenced by the biochemical function of the LT-Ag protein, which is related to the cytopathic effect and tumorigenesis mechanism via interaction with the host protein. METHODS: We carried out a comparative analysis of codon usage patterns of large T-antigens (LT-Ags) of PyVs isolated from various host species and their functional domains and sequence motifs. Parity rule 2 (PR2) and neutrality analysis were applied to evaluate the effects of mutation and selection pressure on codon usage bias. To investigate evolutionary relationships among PyVs, we carried out a phylogenetic analysis, and a correspondence analysis of relative synonymous codon usage (RSCU) values was performed. RESULTS: Nucleotide composition analysis using LT-Ag gene sequences showed that the GC and GC3 values of avian PyVs were higher than those of mammalian PyVs. The effective number of codon (ENC) analysis showed host-specific ENC distribution characteristics in both the LT-Ag gene and the coding sequences of its domain regions. In the avian and fish PyVs, the codon diversity was significant, whereas the mammalian PyVs tended to exhibit conservative and host-specific evolution of codon usage bias. The results of our PR2 and neutrality analysis revealed mutation bias or highly variable GC contents by showing a narrow GC12 distribution and wide GC3 distribution in all sequences. Furthermore, the calculated RSCU values revealed differences in the codon usage preference of the LT-AG gene according to the host group. A similar tendency was observed in the two functional domains used in the analysis. CONCLUSIONS: Our study showed that specific domains or sequence motifs of various PyV LT-Ags have evolved so that each virus protein interacts with host cell targets. They have also adapted to thrive in specific host species and cell types. Functional domains of LT-Ag, which are known to interact with host proteins involved in cell proliferation and gene expression regulation, may provide important information, as they are significantly related to the host specificity of PyVs.

Isolation and characterization of an Aves polyomavirus 1 from diseased budgerigars in China.

Aves polyomavirus 1 (APV) causes inflammatory disease in psittacine birds, especially in young budgerigar. In this study, an APV virus (SD18 strain) was isolated from a diseased psittacine birds breeding facility. The full genome (4981 bp) of SD18 was determined and analyzed. Phylogenetic analysis of full genome sequences indicated all the APV strains form two groups. The SD18 strain showed close relationship with APV isolated from Poland, however, the other Chinese strains are located in group II, which suggested different genotypes APVs are co-circulating in China. Compared with the consensus sequence of APV full genome, the SD18 strain contains 13 nucleotide mutations, and 2 unique amino acid substitutions (R179M and Q382K) located in VP2/3 and Large T proteins. To explore the pathogenicity of the virus, the SD18 strain was used to challenge 2-week-old budgerigars. All infected birds died no later than 5 days post infection, and virus was detected in multiple organs including brain, heart, ingluvies, liver, and intestine, which indicated that SD18 is fatal and causes systemic infection in young budgerigar. In vitro studies showed that SD18 replicated efficiently in CEF cells and reached the highest viral titers at 9 days post infection. Notably, replication of SD18 stimulated IFN-ß response in CEF cells and overexpression of the VP4 or VP4Delta proteins significantly inhibited IFN-ß promoter activation, which could be the strategy of APV to escape from the host innate immunity.

First detection and molecular characterization of avian polyomavirus in young parrots in Pakistan.

Avian polyomavirus (APV) infection, also called as budgerigar fledgling disease (BFD) causes various health problems in many psittacine species which may cause untimely death. The aims of this study were to investigate, for the first time, the detection, molecular characterization and phylogenetic analysis of avian polyomavirus (APV) in Pakistani psittacine birds. In an aviary a disease similar to APV was found and 90% of the nestlings died within a few weeks. Seven to ten-day-old parrot nestlings (n = 3) from the aviary were presented with feather abnormalities, plumage defect and were clinically depressed. Birds died at 11th, 14th and 16th day of age. Samples of hearts, livers, spleen, feathers and kidneys were collected from the dead birds. Samples were analyzed for the presence of APV DNA by using PCR. APV VP1 gene was partially sequenced, and phylogenetic analysis was performed. The APV strain was similar to those previously reported in other areas of the world. The results of this investigation indicate presence of a high frequency of APV infections in psittacine birds in Pakistan.

Development of a colorimetric loop-mediated isothermal amplification assay for rapid and specific detection of Aves polyomavirus 1 from psittacine birds.

A colorimetric loop-mediated isothermal amplification (LAMP) assay was developed for the rapid and specific detection of the T gene of Aves polyomavirus 1 (APyV), a causative agent of budgerigar fledgling disease (BFD) in psittacine birds. The amplification can be completed in 40 min at 60 °C, and the results can be visually detected by the naked eye using hydroxyl naphthol blue as a colorimetric indicator. The assay specifically amplified APyV DNA but not other viral and bacterial nucleic acids. The limit of detection of the assay was 5 × 102 DNA copies/reaction, which was comparable to those of previously reported conventional polymerase chain reaction assays. In the clinical evaluation, the LAMP results showed 100% concordance with those of the previously reported PCR assays with regard to specificity, sensitivity, and percentage of overall agreement, with a kappa value of 1.0. These results indicate that the developed LAMP assay will be a valuable tool for the rapid, sensitive and specific detection of APyV from BFD-suspected psittacine bird samples even in resource-limited laboratories.

Prevalence of Aves Polyomavirus 1 and Beak and Feather Disease Virus From Exotic Captive Psittacine Birds in Chile.

Avian polyomavirus disease and psittacine beak and feather disease (PBFD) are both contagious viral diseases in psittacine birds with similar clinical manifestations and characterized by abnormal feathers. To determine the prevalence of Aves polyomavirus 1 (APyV) and beak and feather disease virus (BFDV) in captive, exotic psittacine birds in Chile, feathers from 250 psittacine birds, representing 17 genera, were collected and stored during the period 2013-2016. Polymerase chain reaction testing was used to detect APyV and BFDV were detected in feather bulb samples. The results indicated that 1.6% (4/250) of the samples were positive for APyV, 23.2% (58/250) were positive to BFDV, and 0.8% (2/250) were positive to both APyV and BFDV. This is the first report, to our knowledge, of APyV and BFDV prevalence in captive, exotic psittacine birds in South America. Analysis of 2 Chilean partial sequences of the gene encoding agnoprotein 1a (APyV) and the replication-associated protein (BFDV) extends the knowledge of genomic variability for both APyV and BFDV isolates and their spectrum of hosts. No geographical marker was detected for the local isolates.

Persistent development of adomavirus and aquareovirus in a novel cell line from marbled eel with petechial skin haemorrhage.

In Taiwan, a petechial haemorrhage disease associated with mortality has affected marbled eels (Anguilla marmorata). The eels were revealed to be infected with adomavirus (MEAdoV, previously recognized as a polyoma-like virus). In this study, cell line DMEPF-5 was established from the pectoral fin of a diseased eel. DMEPF-5 was passaged >70 times and thoroughly proliferated in L-15 medium containing 2%-15% foetal bovine serum at 20-30°C. Transcripts of neural cell adhesion molecule 1 and nestin genes, and nucleic acids of MEAdoV and a novel reovirus (MERV) in the cells were demonstrated by reverse transcription-polymerase chain reaction analysis. Phylogenetic analysis revealed that the AdoV LO8 proteins mostly relate to adenovirus adenain, whereas MERV is close to American grass carp reovirus in Aquareovirus G, based on a partial VP2 nucleotide sequence. DMEPF-5 cells are susceptible to additional viral infection. Taken together, the marbled eels with the haemorrhagic disease have coinfection with MEAdoV and MERV, and the pathogenic role of MEAdoV and MERV warrants research. DMEPF-5 has gene expression associated with mesenchymal stem and progenitor cells and is the first cell line persistently infected with adomavirus and aquareovirus. DMEPF-5 can facilitate studies of such viruses and haemorrhagic disease.

Establishment of rapid detection method and surveillance of budgerigar fledgling disease virus using a TaqMan Real-Time PCR.

Budgerigar fledgling disease virus (BFDV) infection causes sudden death, abdominal distention, and feather abnormality in psittacine birds. In this study, we developed a TaqMan Real-time PCR assay to detect BFDV by targeting a conserved region in VP1 gene. The detection limit of the assay was 30 DNA gene copies, 1000 times more sensitive than conventional PCR. The coefficients of variation were less than 1.09% in either intra- or inter-assays, indicating high reproducibility. By using this method, the prevalence of BFDV in China was evaluated. 56 feces samples were collected from four psittacine birds breeding facilities in China. The results showed 28 out of 56 samples were positive for BFDV in Real-Time PCR assay, while only 19 samples were positive in PCR assay. Three facilities were positive for BFDV with positive rates from 60% to 87.5%. Further sequence analysis of VP1 genes from the positive samples indicated that VP1 genes fell into two different lineages in phylogenetic tree, suggesting that different genotypes BFDV are co-circulating in China.

Genomic analysis of Sheldrake origin goose hemorrhagic polyomavirus, China.

Goose hemorrhagic polyomavirus (GHPV) is not a naturally occurring infection in geese in China; however, GHPV infection has been identified in Pekin ducks, a domestic duck species. Herein, we investigated the prevalence of GHPV in five domestic duck species (Liancheng white ducks, Putian black ducks, Shan Sheldrake, Shaoxing duck, and Jinyun Sheldrake) in China. We determined that the Jinyun Sheldrake duck species could be infected by GHPV with no clinical signs, whereas no infection was identified in the other four duck species. We sequenced the complete genome of the Jinyun Sheldrake origin GHPV. Genomic data comparison suggested that GHPVs share a conserved genomic structure, regardless of the host (duck or geese) or region (Asia or Europe). Jinyun Sheldrake origin GHPV genomic characterization and epidemiological studies will increase our understanding of potential heterologous reservoirs of GHPV.

New polyomavirus species identified in nutria, Myocastor coypus polyomavirus 1.

A novel polyomavirus (PyVs) comprising 5,422 bp was identified by high-throughput sequencing (HTS) in pooled organs of nutria (Myocastor coypus). The new genome displays the archetypal organization of PyVs, which includes open reading frames for the regulatory proteins small T antigen (sTAg) and large T antigen (LTAg), as well as for the capsid proteins VP1, VP2 and VP3. Based on the International Committee on Taxonomy of Viruses (ICTV) Polyomaviridae Study Group criteria, this genome comprises a new PyVs species for the Alphapolyomavirus genus and is putatively named "Myocastor coypus Polyomavirus 1" . The complete genome sequence of this Myocastor coypus Polyomavirus 1 (McPyV1) isolate is publically available under the GenBank accession no. MH182627.