Publications

cloning and characterization of budgerigar fledgling disease virus, an avian polyomavirus.	the dna of a virus isolated from fledgling budgerigars, designated bfdv, was cloned and analyzed with regard to its relationship to the polyomavirus subgroup of the papovavirus family. under relaxed conditions, the dna of bfdv cross-hybridized with the dnas of members of the polyomavirus subgroup, such as the mouse polyomavirus, the monkey viruses simian virus 40, stump-tailed macaque virus, and lymphotropic papovavirus, and the human viruses jcv and bkv. under stringent conditions, however, no ...	1986	3010557
the genome of budgerigar fledgling disease virus, an avian polyomavirus.	budgerigar fledgling disease virus (bfdv) represents the first avian member of the polyomavirus family. in contrast to mammalian polyomaviruses bfdv exhibits unique biological properties, in particular it is able to cause an acute disease with distinct organ manifestations in affected birds. here we present the complete nucleotide sequence of the bfdv genome, consisting of 4980 bp. when compared to published nucleotide sequences of other polyomaviruses, the bfdv genome exposes a number of very s ...	1988	2838972
myristoylation of budgerigar fledgling disease virus capsid protein vp2.	we present evidence that the structural protein vp2 of budgerigar fledgling disease virus, an avian polyomavirus, is specifically modified by covalent attachment of myristic acid. the fatty acid linkage is insensitive to hydroxylamine treatment and thus represents the amide type of fatty acylation of proteins.	1989	2535744
polymerase chain reaction assay for avian polyomavirus.	a polymerase chain reaction assay was developed for detection of budgerigar fledgling disease virus (bfdv). the assay used a single set of primers complementary to sequences located in the putative coding region for the bfdv vp1 gene. the observed amplification product had the expected size of 550 bp and was confirmed to derive from bfdv dna by its restriction digestion pattern. this assay was specific for bfdv and highly sensitive, being able to detect as few as 20 copies of the virus. by using ...	1991	1647403
organ distribution of avian polyomavirus dna and virus-neutralizing antibody titers in healthy adult budgerigars.	tissue specimens and serum samples obtained from adult budgerigars in various stages of reproduction housed in an aviary with enzootic avian polyomavirus (apv) disease were examined by means of polymerase chain reaction techniques for apv dna. although the birds were apparently healthy, apv dna could be detected in all 40 birds examined (inapparent infection rate, 100%). viral dna was found in most organ systems examined. analysis of data suggested that organ virus concentrations were lower in b ...	1993	8116935
infection with the avian polyomavirus, bfdv, selectively affects myofibril structure in embryonic chick ventricle cardiomyocytes.	embryonic cardiomyocytes can both beat and divide. they assemble cardiac muscle-specific proteins into sarcomeric myofibrils and contract. in addition, they periodically synthesize dna, complete mitosis, disassemble sarcomeric myofibrils in the area of the mitotic spindle, assemble cytoplasmic isoform-specific proteins into a cleavage furrow contractile ring, undergo cytokinesis, and then reform sarcomeric myofibrils in daughter cells. little is known about how embryonic cardiomyocytes disassemb ...	1993	8228865
diagnosis of polyomavirus-induced hepatic necrosis in psittacine birds using dna probes.	liver sections from 32 psittacine birds with multifocal to coalescing hepatocellular necrosis were examined to determine the cause of disease. avian polyomavirus (apv) infection (19 of 32 birds), bacterial hepatitis (5 of 32 birds), and chlamydiosis (3 of 32 birds) were major causes of hepatic disease. the presence of apv inclusions or nucleic acid was demonstrated using hematoxylin and eosin (he) staining, dna in situ hybridization, and dna amplification with southern blotting. amphophilic intr ...	1994	7524692
host restriction in the productive cycle of avian polyomavirus budgerigar fledgling disease virus type 3 depends on a single amino acid change in the common region of structural proteins vp2/vp3.	the three avian polyomaviruses budgerigar fledgling disease virus types 1 to 3 (bfdv-1 to -3) contain genomes of identical size, 4981 bp. with differences of up to only 15 bp between the three genomes, these viruses show distinct tropism for cultured cells of various avian species: infection of chicken embryo (ce) cells with bfdv-1 and -2 results in virus propagation, whereas bfdv-3 is not replicated; all three viruses replicate, with different efficiencies, in infected muscovy duck cells. trans ...	1994	8077924
diagnosis of polyomavirus infection in seedcrackers (pyrenestes sp.) and blue bills (spermophaga haematina) using dna in situ hybridization.	avian polyomavirus (apv) infection was diagnosed in a closed research colony of seedcrackers (pyrenestes sp.) and blue-bills (spermophaga haematina) using dna in situ hybridization. the dna probe was a 1-kbp double-stranded pcr-generated probe that recognized a conserved nucleotide sequence within the vp-1 gene. using this technique, apv infection was diagnosed, in 25 of 45 birds based upon examination of formalin-fixed paraffin embedded tissues. birds infected with apv apparently had a higher i ...	1994	18671119
diagnosis of psittacine beak and feather disease (pbfd) viral infection, avian polyomavirus infection, adenovirus infection and herpesvirus infection in psittacine tissues using dna in situ hybridization.	the evaluation of the usefulness of dna probes in a diagnostic setting to identify nuclear inclusions in selected viral infections (psittacine beak and feather disease viral infection, avian polyomavirus infection, adenovirus infection and pacheco's parrot disease) is reported. a dna in situ hybridization method was used to detect viral nucleic acid in sections of paraffin-embedded tissues coming from birds naturally and/or experimentally infected. it is concluded that dna probes used for polyom ...	1994	18671131
early and late pre-mrna processing of budgerigar fledgling disease virus 1: identification of viral rna 5' and 3' ends and internal splice junctions.	budgerigar fledgling disease virus 1 (bfdv-1) is the first avian polyomavirus to be identified, and it possesses uncommon structural and biological properties. here we present an analysis of the processed viral rnas in infected chicken embryo fibroblast cells. two early and 18 late bfdv-1 mrnas were defined according to their 5' ends and internal splice patterns. in the early region of the genome an incomplete splice reaction covering 195 nt is responsible for creating two mrnas that could encod ...	1995	7844527
development and application of an immunohistochemical staining technique to detect avian polyomaviral antigen in tissue sections.	an immunohistochemical staining technique was developed to detect polyomaviral antigens of budgerigar fledgling disease in formalin-fixed tissue sections. this technique used an indirect avidin-biotin, alkaline phosphatase labeling system with a mixture of monoclonal antibodies developed against the virus major capsid protein. the staining technique was applied retrospectively to 24 avian accessions which were originally diagnosed as budgerigar fledgling disease or avian polyomavirus infection b ...	1995	8580163
failure of maternally derived yolk igg to reach detectable concentrations in the sera of nestling budgerigars (melopsittacus undulatus).	transfer of maternal immunoglobulin g (igg) to the yolk and nestling was investigated in the budgerigar. specific antibodies to avian polyomavirus and newcastle disease virus could be detected in 82% of yolk extracts of eggs from seropositive hens. using a double immunodiffusion assay with anti-chicken igg antibodies, igg could also be detected in yolk supernatants with virus neutralizing activity. in all assays, igg concentrations in the yolk extracts were significantly less than those of the a ...	1995	8719202
production of avian polyomavirus seronegative budgerigars (melopsittacus undulatus) from seropositive adults.	adult budgerigars (melopsittacus undulatus) with 2 years of breeding experience were removed from an aviary with enzootic avian polyomavirus (apv) disease and maintained in an isolation unit. following a 7-month respite from breeding, these birds were allowed to breed without interruption for 2 years. although the adults were seropositive both at the beginning and end of the experiment, all 102 of their offspring were seronegative. these data suggest that apv can be eliminated from a budgerigar ...	1995	8719226
development of a chicken model for studying avian polyomavirus infection.	the purpose of this study was to develop a chicken model for studying the pathogenesis of avian polyomaviral infection. ninety-two 1-day-old specific-pathogen-free (spf) chicks were divided into the following three treatment groups: nontreated controls, treated with cyclosporine and treated with cyclophosphamide (cy). all birds were inoculated with polyomavirus; half were orally inoculated and half were inoculated by intraperitoneal (ip) injection. spontaneous mortality and lesion development co ...	1996	8790889
polyomavirus encephalopathy in a ducorps' cockatoo (cacatua ducorpsii) with psittacine beak and feather disease.	necropsy tissues were examined from an adult wild-caught ducorps' cockatoo (cacatua ducorpsii) with progressive neurologic signs. of the tissue specimens selected for histologic evaluation, only the brain contained rare amphophilic, glassy intranuclear inclusions within astrocytes and some neurons. astrocyte and neuronal degeneration and necrosis also were observed. scattered astrocytes, with and without discernable inclusions, contained avian polyomavirus (apv) nucleic acid, as determined by dn ...	1996	8844570
characterization of a calcium binding domain in the vp1 protein of the avian polyomavirus, budgerigar fledgling disease virus.	calcium ions appear to play a major role in maintaining the structural integrity and assembly of papovavirus virions and are likely involved in the process of viral uncoating. recently it was reported that the purified recombinant vp1 protein of budgerigar fledgling disease virus (bfdv) was capable of assembling into capsid-like particles in the presence of calcium. it is now reported that the major capsid protein vp1 of bfdv binds calcium ions in an in vitro calcium binding assay. two deletions ...	1996	8879141
an inactivated avian polyomavirus vaccine is safe and immunogenic in various psittaciformes.	the safety and immunogenicity of adjuvanted and nonadjuvanted inactivated avian polyomavirus vaccines, administered either intramuscularly or subcutaneously (s.c.), were evaluated in a group of mixed species psittaciformes. in 233 vaccinates representing species of macaws, cockatoos, conures, and parrots, gross reactions were limited to small scab formation at the s.c. injection site in three african grey parrots. both vaccines stimulated a virus neutralizing (vn) antibody response, particularly ...	1996	8911004
characterization of the avian polyomavirus-associated glomerulopathy of nestling parrots.	the glomerulopathy occurring in nestling nonbudgerigar parrots with avian polyomavirus (apv) disease was examined in 10 parrots. glomerular lesions were characterized by the presence of dense, periodic acid-schiff (pas)-positive material that expanded the mesangium and that narrowed and at times occluded capillary lumina. pas-staining was found to be more sensitive than hematoxylin and eosin in the detection of the lesions. ultrastructurally, finely granular electron-dense material was found in ...	1996	8713028
the effect of space flight on monoclonal antibody synthesis in a hybridoma mouse cell line.	the hybridoma cell line, 3g10g5, producing a monoclonal antibody to the major capsid protein vp1 from the avian polyomavirus budgerigar fledgling disease virus, was produced from a balb/c mouse. this cell line was used to test the effects of microgravity on cellular processes, specifically protein synthesis. a time course study utilizing incorporation of [35s]methionine into newly synthesized monoclonal antibody was performed on sts-77. after 5.5 days, it was observed that cell counts for the sa ...	1997	9024803
fatal avian polyomavirus infection during quarantine in adult wild-caught red-faced lovebirds (agapornis pullaria).	an outbreak of avian polyomavirus infection is reported in a group of six wild-caught red-faced lovebirds (agapornis pullaria), all of which died during quarantine. the birds had not shown any previous symptoms. histologic examination of the lungs, kidneys, livers, and spleens revealed the presence of basophilic intranuclear inclusions. avian polyomavirus was isolated from the liver and the spleen. neutralizing antibodies were detected in the sera from other lovebirds (agapornis personata, agapo ...	1997	9201423
safety, immunogenicity, and efficacy of an inactivated avian polyomavirus vaccine.	to determine safety, immunogenicity, and efficacy of an inactivated avian polyomavirus vaccine in nonbudgerigar psittacine birds that varied in age, species, and immunologic status.	1998	9492926
avian polymavirus in wild birds: genome analysis of isolates from falconiformes and psittaciformes.	avian polyomavirus (apv) infections have been reported to cause fatal disease in a wide range of psittacine species. here we demonstrate apv infections in buzzards (buteo buteo) and in a falcon (falco tinnunculus) found dead in germany, and in lovebirds (agapornis pullaria) with fatal disease, wild-caught in moçambique. apv infection in buzzards was determined by pcr amplification of parts of the viral genome followed by southern blot hybridisation. the genomes of the isolates obtained from the ...	1998	9739329
a concurrent outbreak of psittacine beak and feather disease virus, and avian polyomavirus infection in budgerigars (melopsittacus undulatus).	a dual natural infection with psittacine beak and feather disease virus and budgerigar fledgling disease virus in a breeding aviary of budgerigars (melopsittacus undulatus) is described. one-hundred per cent of newly-hatched birds were affected and mortality was high (85%). most surviving birds had diarrhoea, feather alterations and 30% mortality after a 5- to 10-week period. necropsies of 1-week-old and 2-month-old birds demonstrated non-specific lesions, but histologically nuclear inclusions s ...	1998	18483964
a serologic survey for avian polyomavirus and pacheco's disease virus in australian cockatoos.	sera collected from wild and captive australian cockatoos and other psittacine species (n = 411) were tested for antibodies to avian polyomavirus (apv) and pacheco's disease virus (pdv). of 144 wild sulphur-crested cockatoos (cacatua galerita) sampled at three regions in new south wales (nsw) 96 (64.4%) birds had positive (>/= 1:32) neutralizing antibody titres to avian polyomavirus (range 1:32-1:2048). two of 17 wild long-billed corellas (cacatua tenuirostris) were also apv-antibody positive. h ...	1998	18483996
[polyomavirus infections in exotic birds in switzerland].	polyomavirus infections in budgerigars, in other parrots as well as in passeriformes have been described in many countries, but not in switzerland so far. this paper reports on cases of polyomavirus infections in three different bird collections in switzerland. the first outbreak occurred in a mixed collection of passeriformes, the second in a collection of parrotlets (genus forpus), and the third in a large groups of parrots (psittaciformes), of which only one recently acquired kea (nestor nota ...	1999	10354740
genetic diversity in twenty variants of the avian polyomavirus.	to determine if different pathotypes of the avian polyomavirus (apv) exist and to compare the genomes of apvs originating from different geographic areas, dates, and species of birds, the partial sequences of 18 apvs were determined. new viral sequences were compared with three published apv sequences. two of the new viruses had identical sequences. forty point mutations were found at 31 loci. a 27-bp deletion was found in the vp2 and vp3 open reading frames of one virus. a duplication of the pu ...	1999	10396633
experimental inoculation of avian polyomavirus in chemically and virally immunosuppressed chickens.	the purpose of this series of experiments was to determine the effect of various types of immunosuppressive treatments (cyclophosphamide, infectious bursal disease virus [ibdv], chicken anemia virus [cav], and combination infection with ibdv and cav) on susceptibility of chickens to challenge with avian polyomavirus. in the first experiment, chickens were chemically bursectomized with intraperitoneal injections of cyclophosphamide; in the second study, chickens were orally inoculated with ibdv; ...	1999	10494416
avian polyomavirus infection and disease in a green aracaris (pteroglossus viridis).	avian polyomavirus (apv) is one of the most significant pathogens of domestically raised psittacine birds (parrots). one or more apvs are suspected to infect nonpsittacine cage birds, but the relationship of these viruses to the apv infecting parrots remains unclear. in this report, for the first time, we fully document an apv infection in a nonpsittacine cage bird, a green aracaris (pteroglossus viridis). grossly, this bird evidenced generalized hemorrhage. histologically, there was severe hepa ...	1999	10494430
avian polyomavirus major capsid protein vp1 interacts with the minor capsid proteins and is transported into the cell nucleus but does not assemble into capsid-like particles when expressed in the baculovirus system.	the baculovirus system was used to construct and isolate acmnpv-vp1, acmnpv-vp2 and acmnpv-vp3 recombinant viruses which express the respective avian polyomavirus (apv) structural proteins in sf9 insect cells. these recombinant acmnpvs containing apv structural protein genes were utilized to investigate protein-protein interactions between the structural proteins. immunofluorescence studies utilizing sf9 cells infected with the acmnpv-vp1 revealed that the vp1 protein was expressed and localized ...	1999	10518713
recombinant expression of late genes agno-2a and agno-2b of avian polyomavirus bfdv.	budgerigar fledgling disease virus (bfdv) genome contains two times two (two pairs) open reading frames (agnogenes) at the 5' end of the late coding region. recombinant influenza a viruses were constructed to express the second pair of bfdv agnoproteins, agno-2a and agno-2b, with a fusion of a histidine-tag at their carboxy-termini, respectively. specific proteins were detected in western blot analysis using anti histidine-tag monoclonal antibody. by indirect immunofluorescence experiments agno- ...	1999	10595409
agnoprotein-1a of avian polyomavirus budgerigar fledgling disease virus: identification of phosphorylation sites and functional importance in the virus life-cycle.	the avian polyomavirus budgerigar fledgling disease virus (bfdv) encodes an unusual set of four agnoproteins in its late upstream region. of the two pairs of these proteins, which overlap each other in two different reading frames, the p(l1)-promoted agnoprotein-1a (agno-1a) is the dominant species and is able to support virus propagation in the absence of the other three polypeptides. viral bfdv agno-1a, and also agno-1a expressed via an influenza virus vector, consists of a complex series of e ...	2000	10644834
evidence for translation of vp3 of avian polyomavirus bfdv by leaky ribosomal scanning.	due to several incomplete splicing reactions, budgerigar fledgling disease virus (bfdv) late mature mrnas are either bicistronic or polycistronic with an agnogene located upstream of viral protein (vp) genes. while the bicistronic mrnas code for the vast majority of vp1, the polycistronic mrnas contain the coding sequences of vp2, vp3, and vp1 (as the most distal cistron relative to vp2 and vp3). in this work, the translation initiation mechanism of vp3 was investigated in chicken embryo fibrobl ...	2000	10752562
agnoprotein 1a and agnoprotein 1b of avian polyomavirus are apoptotic inducers.	avian polyomavirus (apv) causes an acute fatal disease in a variety of avian species. dna laddering indicating apoptosis was demonstrated in apv-infected chicken embryo (ce) cells. dna laddering, however, was not observed in vero cells infected with mammalian polyomavirus simian virus 40. expression of apv agnoprotein 1a and agnoprotein 1b induced apoptosis in insect cells and ce cells. an apv full-length plasmid transfected in ce cells induced apoptosis, and infectious virus was produced. after ...	2000	10769059
severe leukopenia and liver necrosis in young african grey parrots (psittacus erithacus erithacus) infected with psittacine circovirus.	this paper describes the signs, clinical pathology, and postmortem findings in 14 young african grey parrots (psittacus erithacus erithacus) that were naturally infected with psittacine beak and feather disease (pbfd) virus (psittacine circovirus). all but two of the parrots had severe leukopenia at clinical presentation. two other parrots also had severe anemia. all birds died within 3 wk after presentation. postmortem examination documented liver necrosis in 11 of 14 birds and secondary bacter ...	2000	10879931
viremia, virus shedding, and antibody response during natural avian polyomavirus infection in parrots.	to determine rapidity of spread and onset and duration of viremia, virus shedding, and antibody production in parrots naturally infected with avian polyomavirus (apv).	2000	10909443
recombinant expression and modification analysis of protein agno-1b encoded by avian polyomavirus bfdv.	among two pairs of agnoproteins encoded in upstream positions in the late mrnas of avian polyomavirus bfdv, either agno-1a or its splice derivative agno-1b are required for viral propagation. out of the two proteins both of which consist of multiple electrophoretic subspecies, the smaller and less complex agno-1b has been cdna-cloned into an influenza-virus /rna-polymerase i expression system for production of higher amounts of this protein in infected chicken embryo fibroblasts. fractional modi ...	2000	10948993
development of a blocking enzyme-linked immunosorbent assay for the detection of avian polyomavirus-specific antibodies.	avian polyomavirus, described originally as budgerigar fledgling disease virus, has been associated with devastating contagious disease outbreaks in budgerigar aviaries. at present, this virus affects a wide range of psittacine and non-psittacine birds worldwide, and the serum neutralisation test is used for the serodiagnosis of avian polyomavirus infections. a blocking enzyme-linked immunosorbent assay was developed for the screening of large numbers of sera collected from various avian species ...	2000	10996638
avian polyomavirus agnoprotein 1a is incorporated into the virus particle as a fourth structural protein, vp4.	agnoproteins, encoded by the 5'-region of the late bicistronic mrna of some polyomaviruses, are small proteins with largely unknown functions. in avian polyomavirus (apv)-infected cells, mrnas of seven putative agnoproteins have been observed. recently, it has been shown that agnoprotein 1a and its truncated variant agnoprotein 1b, encoded by the predominant mrna species, are essential for apv replication. here, the presence of agnoprotein 1a is demonstrated in the nucleus of apv-infected cells ...	2001	11257197
herpesviral, but no papovaviral sequences, are detected in cloacal papillomas of parrots.	internal papillomatosis of parrots (ipp) is a tumour disease with unknown etiology, characterised by progressive development of papillomas in the oral and cloacal mucosa. based on epidemiologic data, infectious agents, particularly dna tumour viruses, are considered to be involved. in this study, cloacal papillomas were investigated by pcr for the presence of herpesvirus, papillomavirus and avian polyomavirus genomes, respectively. using consensus and specific primers, 5 out of 12 papillomas wer ...	2002	12376750
the genome of goose hemorrhagic polyomavirus, a new member of the proposed subgenus avipolyomavirus.	the full-length genome of goose hemorrhagic polyomavirus (ghpv), the ethiologic agent of hemorrhagic nephritis and enteritis of geese, was cloned and sequenced. transfection of the circular ds dna with a size of 5256 bp and an organisation typical of polyomaviruses produced viral progeny in cultured goose cells. according to the splicing sites determined by rt-pcr, five open reading frames (orfs) were found to encode putative proteins with significant similarities to large t antigen and small t ...	2003	12706079
nuclear localization of avian polyomavirus structural protein vp1 is a prerequisite for the formation of virus-like particles.	virions of polyomaviruses consist of the major structural protein vp1, the minor structural proteins vp2 and vp3, and the viral genome associated with histones. an additional structural protein, vp4, is present in avian polyomavirus (apv) particles. as it had been reported that expression of apv vp1 in insect cells did not result in the formation of virus-like particles (vlp), the prerequisites for particle formation were analyzed. to this end, recombinant influenza viruses were created to (co)e ...	2004	14694124
detection of avian polyomavirus infection by polymerase chain reaction using formalin-fixed, paraffin-embedded tissues.	avian polyomavirus infection in psittacines was diagnosed in tissues by the use of polymerase chain reaction (pcr) test. the tissues used in the procedure were either formalin-fixed tissues embedded in paraffin blocks or fresh tissues (heart, liver, and spleen) collected from the psittacines during necropsy. dna was extracted from these tissues and was tested with the published primers for avian polyomavirus vp1 gene in the pcr that yielded an amplicon of 550 base pair size, which was then visua ...	2004	15283428
a survey to detect subclinical polyomavirus infections of captive psittacine birds in germany.	infections of avian polyomavirus (apv) are known to cause fatal disease in a wide range of psittacine and non-psittacine birds. here, we present a survey to investigate the existence of subpopulation of persistent or subclinically infected parrots inside the population of captive psittacine birds in germany. dna was isolated from feathers of 85 symptom-free birds from 20 different genera (all psittaciformes) taken from 30 different breeders from all over germany. the presence of apv was analysed ...	2004	15607086
detection of beak and feather disease virus (bfdv) and avian polyomavirus (apv) dna in psittacine birds in italy.	beak and feather disease (psittacine circovirus) and budgerigar fledgling disease (avian polyomavirus) are viral diseases that can frequently affect captive psittacine birds. we designed the first survey to investigate the presence of beak and feather disease virus (bfdv) and avian polyomavirus (apv) inside the population of captive psittacine birds in italy. samples were collected in 18 italian psittacine breeding centres and four trade centres over a 4-year period. a total of 1516 birds were t ...	2005	15752264
duplex shuttle pcr for differential diagnosis of budgerigar fledgling disease and psittacine beak and feather disease.	two common viral diseases in psittacine birds including budgerigar fledgling disease (bfd), generally called avian polyomavirus (apv) infection, and psittacine beak and feather disease (pbfd) have similar clinical manifestations characterized by feather disorders. a duplex shuttle pcr was developed for detection of apv and pbfd virus (pbfdv). two pairs of oligonucleotide primers were designed to amplify a 298-bp fragment of the t/t antigen region of apv genome and a 495-bp fragment of the capsid ...	2005	15781996
outbreak of avian polyomavirus infection with high mortality in recently captured crimson's seedcrackers (pyrenestes sanguineus).	avian polyomavirus (apv) infection of recently imported crimson's seedcrackers (pyrenestes sanguineus) resulted in mortality in 56 of 70 (80%) birds in january 2000. viral infection in these birds was characterized by diarrhea, anorexia, and lethargy, and death usually ensued within 48 to 72 hr of initial clinical signs. bacteriologic testing resulted in consistently negative results. histologic examination of tissues from dead birds revealed large intranuclear inclusion bodies, which at electro ...	2005	15827229
characterization of two novel polyomaviruses of birds by using multiply primed rolling-circle amplification of their genomes.	polyomaviruses are small nonenveloped particles with a circular double-stranded genome, approximately 5 kbp in size. the mammalian polyomaviruses mainly cause persistent subclinical infections in their natural nonimmunocompromised hosts. in contrast, the polyomaviruses of birds--avian polyomavirus (apv) and goose hemorrhagic polyomavirus (ghpv)--are the primary agents of acute and chronic disease with high mortality rates in young birds. screening of field samples of diseased birds by consensus ...	2006	16537620
an outbreak of the polyomavirus infection in budgerigars and cockatiels in slovakia, including a genome analysis of an avian polyomavirus isolate.	in winter 2003-04, large numbers of budgerigars (mellopsitacus undulatus) and cockatiels (nymphicus hollandicus) fell ill and died in a large parrot-breeding aviary in slovakia. in budgerigars, the disease outbreak occurred at the age of 2-3 weeks; cockatiels died within their first 7 days of life. in budgerigars, symptoms of the disease included delayed growth, tremor, darkish discoloration of skin, quill bleeding, and feathering defects. cockatiels often died without any symptoms and with a fu ...	2006	16617994
phylogenomics and molecular evolution of polyomaviruses.	we provide in this chapter an overview of the basic steps to reconstruct evolutionary relationships through standard phylogeny estimation approaches as well as network approaches for sequences more closely related. we discuss the importance of sequence alignment, selecting models of evolution, and confidence assessment in phylogenetic inference. we also introduce the reader to a variety of software packages used for such studies. finally, we demonstrate these approaches throughout using a data s ...	2006	16626026
comparing phylogenetic codivergence between polyomaviruses and their hosts.	seventy-two full genomes corresponding to nine mammalian (67 strains) and two avian (5 strains) polyomavirus species were analyzed using maximum likelihood and bayesian methods of phylogenetic inference. our fully resolved and well-supported (bootstrap proportions > 90%; posterior probabilities = 1.0) trees separate the bird polyomaviruses (avian polyomavirus and goose hemorrhagic polyomavirus) from the mammalian polyomaviruses, which supports the idea of spitting the genus into two subgenera. s ...	2006	16731904
a survey of avian polyomavirus (apv) infection in imported and domestic bred psittacine birds in japan.	although birds infected with avian polyomavirus (apv) subclinically could be a source of infection, no epidemiological studies of apv in psittacine birds have been reported in japan. in the present study, we investigated subclinical morbidity rate of apv in imported and domestically bred psittacine birds by polymerase chain reaction (pcr). of 402 live birds from which blood or feather samples were taken between april, 2003 and march, 2004, 11 (2.7%) were found to be apv positive. the dna sequenc ...	2006	16891790
detection and sequence analysis of avian polyomavirus and psittacine beak and feather disease virus from psittacine birds in taiwan.	avian polyomavirus (apv) and psittacine beak and feather disease virus (pbfdv) are the most common viral diseases of psittacine birds. in taiwan, however, the existence of these viruses in psittacine birds has not been established. polymerase chain reaction (pcr) methodology was therefore employed to ascertain whether apv and pbfdv genomes were present in isolates from psittacine birds of taiwan. a total of 165 psittacine birds belonging to 22 genera were examined between 2002 and 2005. findings ...	2006	17039833
avian polyomavirus mutants with deletions in the vp4-encoding region show deficiencies in capsid assembly and virus release, and have reduced infectivity in chicken.	avian polyomavirus (apv) is the causative agent of an acute fatal disease in psittacine and some non-psittacine birds. in contrast to mammalian polyomaviruses, the apv genome encodes the additional capsid protein vp4 and its variant vp4delta, truncated by an internal deletion. both proteins induce apoptosis. mutation of their common initiation codon prevents virus replication. here, the generation of replication competent deletion mutants expressing either vp4 or vp4delta is reported. in contras ...	2007	17325354
[detection of dna of the finch polyomavirus in diseases of various types of birds in the order passeriformes].	between 2000 and 2004 a disease occurred in an aviary in germany affecting various bird species belonging to the order passeriformes including collared grosbeaks (mycerobas affinis), eurasian bullfinches (pyrrhula pyrrhula griseiventris), brown bullfinches (pyrrhula nipalensis), grey-headed bullfinches (pyrrhula erythaca) and yellow-bellied tits (periparus venustulus). the major clinical signs included increased mortality of fledglings and young birds, as well as feather disorders and feather lo ...	2007	17416133
mycobacterium genavense and avian polyomavirus co-infection in a european goldfinch (carduelis carduelis).	systemic mycobacteriosis associated with avian polyomavirus infection was diagnosed histologically in an 8-year-old, captive european goldfinch with a history of nervous signs. severe mycobacterial lesions were observed in the central nervous system, lungs, cervical air sacs and adrenal glands, without involvement of the gastrointestinal tract. in addition to mycobacteriosis, intranuclear inclusions, typical of polyomavirus, were identified in the adrenal glands. polymerase chain reaction assays ...	2007	17899468
infectious offspring: how birds acquire and transmit an avian polyomavirus in the wild.	detailed patterns of primary virus acquisition and subsequent dispersal in wild vertebrate populations are virtually absent. we show that nestlings of a songbird acquire polyomavirus infections from larval blowflies, common nest ectoparasites of cavity-nesting birds, while breeding adults acquire and renew the same viral infections via cloacal shedding from their offspring. infections by these dna viruses, known potential pathogens producing disease in some bird species, therefore follow an 'upw ...	2007	18060070
comparison of three template preparation methods for routine detection of beak and feather disease virus and avian polyomavirus with single and nested polymerase chain reaction in clinical specimens.	direct comparisons are important when assessing the value of dna extraction methods for diagnostic virology as the inhibitors present and the efficiency of extraction vary with the target infectious agent as well as the species and the site from which the clinical sample was obtained. three dna extraction methods were compared for routine polymerase chain reaction (pcr) detection of beak and feather disease virus (bfdv) in whole blood and feather samples and of avian polyomavirus (apv) in feathe ...	2008	18393092
development of novel real-time pcr assays for detecting dna virus infections in psittaciform birds.	viral diseases of psittacine birds are detected presently by pcr. however, conventional pcr methods are not quantitative and the products can sometimes include non-specific products of the same size. to avoid these problems, real-time pcr assays based on the sybr green assay system were developed for the detection and quantitation of four virus diseases of psittacine birds: psittacine beak and feather disease, avian polyomavirus infection, psittacid herpesvirus infection, and psittacine adenovir ...	2008	18824037
molecular characterizations of avian polyomavirus isolated from budgerigar in china.	budgerigar fledgling disease is an acute viral infectious disease caused by avian polyomavirus (apv). in this study, 34 liver tissue samples of young, dead budgerigar with typical symptoms were collected in 2004. all the samples had positive polymerase chain reaction (pcr) test based on the vp1 specific primers. vp1 genes of these samples were sequenced and had high similarities to each other (99%-100%). a strain (hbym02) was isolated and sequenced. as shown in the phylogenetic tree, there are t ...	2008	18939634
avian polyomavirus expression patterns of bicistronic late mrnas.	avian polyomavirus (apv, previously called budgerigar fledgling disease virus, bfdv-1) differs from other polyoma viruses by a complex arrangement within its late genes: p(l1)-promoted agno-genes 1a and 1b overlap p(l2)-promoted agno-genes 2a and 2b in different reading frames, and are located upstream of standard late vp genes. as a minimal set, agno-gene 1a plus vp1, vp2, vp3 support effective viral propagation in cell culture, together with the origin-region and t-antigen section. all viral l ...	2009	19329136
molecular characterization of avian polyomavirus isolated from psittacine birds based on the whole genome sequence analysis.	seven avian polyomaviruses (apvs) were isolated from seven psittacine birds of four species. their whole genome sequences were genetically analyzed. comparing with the sequence of bfdv1 strain, nucleotide substitutions in the sequences of seven apv isolates were found at 63 loci and a high level of conservation of amino acid sequence in each viral protein (vp1, vp2, vp3, vp4, and t/t antigen) was predicted. an a-to-t nucleotide substitution was observed in non-control region of all seven apv seq ...	2009	19345024
histologic, immunohistochemical, and electron microscopic features of a unique pulmonary tumor in cockatiels (nymphicus hollandicus): six cases.	a unique form of pulmonary malignancy develops in cockatiels. this report describes the gross, histologic, electron microscopic, and immunohistochemical features of this tumor in 6 cockatiels. dna in-situ hybridization for polyomavirus in the neoplasm was also performed. the tumor was comprised predominantly of compact sheets of anaplastic round to polygonal cells. all tumors had a high mitotic index, and had occasional large clear to slightly basophilic intranuclear inclusions that caused perip ...	2009	19605913
mortality due to polyomavirus infection in two nightjars (caprimulgus europaeus).	two nightjars (caprimulgus europaeus) from a bird park in the netherlands died suddenly, with no clinical signs, within 1 month of each other. the main pathologic findings at necropsy were splenomegaly and hepatic necrosis. on histologic examination, intranuclear viral inclusion bodies consistent with avian polyomavirus were observed in the liver, spleen, and kidneys. polymerase chain reaction testing of samples from the liver, spleen, and kidneys detected avian polyomaviral dna, and sequence an ...	2009	19673460
a review of dna viral infections in psittacine birds.	to date, several dna viral infections have been reported in psittacine birds. psittacine beak and feather disease (pbfd) is characterized by symmetric feather dystrophy and loss and development of beak deformities. pbfd is caused by beak and feather virus, which belongs to the circoviridae, and is the most important infection in psittacine birds worldwide. avian polyomavirus infection causes acute death, abdominal distention, and feather abnormalities. pacheco's disease (pd), which is caused by ...	2010	20424393
a longitudinal study on avian polyomavirus-specific antibodies in captive spix's macaws (cyanopsitta spixii).	avian polyomavirus (apv) causes a range of disease syndromes in psittacine birds, from acute fatal disease to subclinical infections, depending on age, species, and other unidentified risk factors. to determine the prevalence of apv-specific antibodies in a captive population of spix's macaws (cyanopsitta spixii) in quatar, 54 birds were tested by blocking enzyme-linked immunosorbent assay. a prevalence of 48.1% for apv antibodies, which indicates viral exposure, was found. of 36 spix's macaws t ...	2010	21046939
the structure of avian polyomavirus reveals variably sized capsids, non-conserved inter-capsomere interactions, and a possible location of the minor capsid protein vp4.	avian polyomavirus (apv) causes a fatal, multi-organ disease among several bird species. using cryogenic electron microscopy and other biochemical techniques, we investigated the structure of apv and compared it to that of mammalian polyomaviruses, particularly jc polyomavirus and simian virus 40. the structure of the pentameric major capsid protein (vp1) is mostly conserved; however, apv vp1 has a unique, truncated c-terminus that eliminates an intercapsomere-connecting β-hairpin observed in ot ...	2011	21239031
Avian polyomavirus infection of a fledgling budgerigar (Melopsittacus undulatus) and differential diagnoses of viral inclusions in psittacine birds--case report and mini-review.	A two-week-old budgerigar (Melopsittacus undulatus) of an outdoor aviary died suddenly and was submitted for determination the cause of illness and death. Macroscopically, the sparsely feathered animal was in a poor body condition. Histopathological examination revealed in various mesenchymal and epithelial tissues, numerous up to 15 microm in diameter large intranuclear, amphophilic to basophilic inclusion bodies with a clearing of the centre. Additionally, a feather dysplasia and retention hyp ...	2011	22059291
Prevalence and genetic characterization of avian polyomavirus and psittacine beak and feather disease virus isolated from budgerigars in Mainland China.	Budgerigar fledgling disease (BFD) and psittacine beak and feather disease (PBFD) are caused by avian polyomavirus (APV) and psittacine beak and feather disease virus (PBFDV), respectively. These diseases frequently infect psittacine birds and result in similar clinical manifestations. In this study, we observed the prevalence of PBFDV infection and a dual infection of APV and PBFDV in a budgerigar (Melopsittacus undulatus) in Mainland China for the first time. One PBFDV isolate and two APV isol ...	2011	22002652
seroprevalence of the human polyomavirus 9 (hpyv9) and cross-reactivity to the african green monkey-derived lymphotropic polyomavirus (lpv).	human polyomavirus 9 (hpyv9) was recently discovered in immunocompromised patients and shown to be genetically closely related to the b-lymphotropic polyomavirus (lpyv). no serological data are available for hpyv9, but human antibodies against lpyv have been reported previously. to investigate the seroepidemiology of hpyv9 and the sero-crossreactivity between hpyv9 and lpyv, a capsomer-based igg elisa was established using the major capsid proteins vp1 of hpyv9 and lpyv. vp1 of an avian polyomav ...	2012	22218677
serological cross-reactions between four polyomaviruses of birds using virus-like particles expressed in yeast.	polyomaviruses are aetiological agents of fatal acute diseases in various bird species. genomic analysis revealed that avian polyomavirus (apyv), crow polyomavirus (cpyv), finch polyomavirus (fpyv) and goose hemorrhagic polyomavirus (ghpyv) are closely related to each other, but nevertheless form separate viral species; however, their serological relationship was previously unknown. as only apyv can be grown efficiently in tissue culture, virus-like particles (vlps) were generated by expression ...	2012	22933666
inactivation of stable viruses in cell culture facilities by peracetic acid fogging.	looking for a robust and simple method to replace formaldehyde fumigation for the disinfection of virus-handling laboratories and facilities, we tested peracetic acid fogging as a method to inactivate stable viruses under practical conditions. peracetic acid/hydrogen peroxide (5.8%/27.5%, 2.0 ml/m³) was diluted in sufficient water to achieve ≥ 70% relative humidity and was vaporized as <10 μm droplets in a fully equipped 95 m³ laboratory unit. high titers of reovirus 3, mvm parvovirus and an avi ...	2012	22424718
laboratory reporting accuracy of polymerase chain reaction testing for avian polyomavirus.	polymerase chain reaction (pcr) assays are available for detection of birds infected with avian polyomavirus (apv). several laboratories offer this diagnostic assay in the united states, but little information is available regarding assay sensitivity, specificity, and accuracy. in this study, known apv-positive and apv-negative samples (each n = 10, 5 undiluted and 5 diluted) were sent to 5 commercial laboratories. a significant difference in reporting accuracy was found among laboratories, most ...	2013	23772454
retraction: infectious offspring: how birds acquire and transmit an avian polyomavirus in the wild.		2013	23690907
avian polyomavirus identified in a nestling gouldian finch (erythrura gouldiae) in new zealand.	abstract	2013	23445119
novel ssdna viruses discovered in yellow-crowned parakeet (cyanoramphus auriceps) nesting material.	during routine monitoring of yellow-crowned parakeets in the poulter valley of the south island of new zealand, a dead parakeet chick was discovered in a nest. known parrot-infecting viruses, such as beak and feather disease virus (bfdv), avian polyomavirus (apv), and parrot hepatitis b virus (phbv), were not detected in the nesting material. however, we recovered two novel single-stranded dna viruses (ssdna), cynncxv (2308 nt) and cynnckv (2087 nt), which have genome architectures similar to th ...	2013	23417396
production and biomedical applications of virus-like particles derived from polyomaviruses.	virus-like particles (vlps), aggregates of capsid proteins devoid of viral genetic material, show great promise in the fields of vaccine development and gene therapy. these particles spontaneously self-assemble after heterologous expression of viral structural proteins. this review will focus on the use of virus-like particles derived from polyomavirus capsid proteins. since their first recombinant production 27 years ago these particles have been investigated for a myriad of biomedical applicat ...	2013	23999392
butcherbird polyomavirus isolated from a grey butcherbird (cracticus torquatus) in queensland, australia.	a novel avian polyomavirus was detected in peri-ocular skin lesions collected from a grey butcherbird (cracticus torquatus), using a combination of multiply primed rolling circle amplification, nested pcr and long range pcr. the sequence of butcherbird polyomavirus was determined by combining next generation sequencing and primer walking techniques. the circular double-stranded dna genome of butcherbird polyomavirus consisted of 5084 bp, and encoded six open reading frames (orf-x, vp2, vp3, vp1, ...	2014	24355535
disease screening of three breeding populations of adult exhibition budgerigars (melopsittacus undulatus) in new zealand reveals a high prevalence of a novel polyomavirus and avian malaria infection.	disease surveillance is vital to the management of new zealand's endemic and threatened avian species. three infectious agents that are potential threats to new zealand's endemic birds include avian polyomavirus (apv), beak and feather disease virus (bfdv), and avian malaria. all three agents have been reported in new zealand; however, possible reservoir populations have not been identified. in this communication, we report the first study of apv, bfdv, and avian malaria in introduced adult exhi ...	2014	24758122
complete genome sequence of a novel avian polyomavirus isolated from gouldian finch.	a novel polyomavirus was identified in a fatally diseased gouldian finch (erythrura gouldiae). the new polyomavirus, strain vl 1209, was detected using a broad-spectrum nested pcr.	2015	26383660
identification of an avian polyomavirus associated with adélie penguins (pygoscelis adeliae).	little is known about viruses associated with antarctic animals, although they are probably widespread. we recovered a novel polyomavirus from adélie penguin (pygoscelis adeliae) faecal matter sampled in a subcolony at cape royds, ross island, antarctica. the 4988 nt adélie penguin polyomavirus (adpyv) has a typical polyomavirus genome organization with three orfs that encoded capsid proteins on the one strand and two non-structural protein-coding orfs on the complementary strand. the genome of ...	2015	25537375
avian polyomavirus genome sequences recovered from parrots in captive breeding facilities in poland.	eight genomes of avian polyomaviruses (apvs) were recovered and sequenced from deceased psittacula eupatria, psittacula krameri, and melopsittacus undulatus from various breeding facilities in poland. of these apv-positive samples, six had previously tested positive for beak and feather disease virus (bfdv) and/or parrot hepatitis b virus (phbv).	2015	26404592
survey of captive parrot populations around port phillip bay, victoria, australia, for psittacine beak and feather disease virus, avian polyomavirus and psittacine adenovirus.	this study investigated the prevalence of psittacine beak and feather disease virus (bfdv), avian polyomavirus (apv) and psittacine adenovirus (psadv) in captive psittacine birds around port phillip bay, victoria, australia.	2015	26220322
health assessment of captive psittacine species in prerelease programs at costa rican rescue centers.	with stricter laws regulating the capture and possession of wild animals in costa rica, local wildlife-rescue centers have been overwhelmed by an influx of confiscated or relinquished illegal pets, specifically of psittacine species. as part of a nationwide health-assessment program targeting these centers, 122 birds representing five psittacine species ( ara macao, amazona autumnalis, amazona auropalliata, amazona farinosa, aratinga finschi) and one hybrid macaw ( ara macao × ara ambiguus) were ...	2017	29297799