| investigation into avian pneumovirus persistence in poults and chicks using cyclosporin a immunosuppression. | one-day-old poults or two-week old chicks were infected oculonasally with avian pneumovirus. cloacal swabs were collected for virus isolation as were selected tissues (harderian gland, turbinates, trachea, lungs and kidneys) from birds killed at regular intervals up to 33 days post infection (p.i.) for poults, and up to 40 days p. i. for chicks. in an attempt to induce virus re-excretion, the t-cell-suppressor cyclosporin a (csa) was given for 12 days starting from three weeks p.i. in poults and ... | 1999 | 10208895 |
| a reverse transcription-polymerase chain reaction assay for the detection of avian pneumovirus (colorado strain). | a reverse transcription-polymerase chain reaction assay was developed for the detection of avian pneumovirus (colorado strain) (apv-col). the specific primers were designed from the published sequence of the matrix protein gene of apv-col. the primers amplified a product of 631 nucleotides from apv-col. the assay identified only apv-col and did not react with newcastle disease virus and infectious bronchitis virus. | 1999 | 10494434 |
| molecular characterization of brazilian avian pneumovirus isolates: comparison between immunochemiluminescent southern blot and nested pcr. | avian pneumovirus (apv) causes acute respiratory tract infection both in turkeys (turkey rhinotracheitis) and chickens (swollen head syndrome (shs)) with sudden onset and rapid spread through the flocks. in this study, an immunochemiluminescent southern blot rt-pcr assay was employed to detect a f gene transcript of the apv in two european turkey isolates and two brazilian chicken isolates. limiting dilution pcr was carried out to compare the sensitivity of immunochemiluminescent southern blot a ... | 1999 | 10381093 |
| detection and characterization of proteins encoded by the second orf of the m2 gene of pneumoviruses. | the nucleotide sequence of the m2 gene of pneumonia virus of mice (pvm) was determined. the sequence showed that the gene encoded a protein of 176 amino acids with a predicted molecular mass of 20165 da from a major orf, which is smaller than the equivalent proteins encoded by human, bovine and ovine respiratory syncytial (rs) viruses. the pvm m2 protein is conserved, having 41% similarity to the equivalent human rs virus protein. in common with the m2 genes of the rs viruses and avian pneumovir ... | 1999 | 10466798 |
| infections and reinfections with avian pneumovirus subtype a and b on belgian turkey farms and relation to respiratory problems. | a longitudinal study was performed on six turkey farms in order to determine whether infections with avian pneumovirus (apv) occur and if they are related to outbreaks of respiratory problems in belgium. blood was taken at 1-3 week intervals of 20 identified animals during the fattening period. on five farms, the turkeys seroconverted against apv shortly after the appearance of respiratory problems. on two farms, where the animals had not been vaccinated against apv, attempts were made to isolat ... | 1998 | 9916553 |
| serologic evidence of pneumovirus in chile. | chicken and turkey serum samples were obtained and tested in an enzyme-linked immunosorbent assay to establish the presence or absence of antibodies to avian pneumovirus in the commercial poultry population of chile. a total of 600 serum samples representing 15 different poultry farms of the central region of chile were considered. these samples were obtained from 52 different flocks and included 220 turkey and 380 chicken sera. the results showed three flocks of market turkeys belonging to the ... | 1998 | 9876855 |
| detection of antibodies to avian pneumovirus by a micro-indirect immunofluorescent antibody test. | a micro-indirect immunofluorescent antibody (micro-ifa) test with a 96-well, flat-bottomed microplate was developed for measuring avian pneumovirus (apv) antibodies. two japanese apv strains (mm-1, 8597/cv94) isolated at different places and times and vero cells were used for antigen preparation in this test. the test results were compared with those of a serum neutralization (sn) test. by the micro-ifa test, specific immunofluorescent antigens were observed in the cytoplasm of cells infected wi ... | 1999 | 10494406 |
| nucleotide sequence of the gene encoding the viral polymerase of avian pneumovirus. | we report here the nucleotide sequence of the l gene of avian pneumovirus (apv). this is the second pneumovirus l gene and the second avian paramyxovirus l gene, following that of newcastle disease virus, to be sequenced. the apv l gene is 6099 nucleotides long and encodes a single large orf of 2004 amino acids. this makes the apv l protein the smallest to be described for any nonsegmented, negative-strand rna virus. the protein contains six linear non-contiguous domains, a putative atp-binding ... | 1996 | 9000096 |
| sequence analysis of a functional polymerase (l) gene of bovine respiratory syncytial virus: determination of minimal trans-acting requirements for rna replication. | the complete nucleotide sequence of a functional clone of the large polymerase (l) gene of bovine respiratory syncytial virus (brsv) strain a51908 was determined by analysis of cloned cdnas obtained from genomic and mrnas. the brsv l gene is 6573 nt in length and the derived polypeptide has 2162 aa. alignment of the sequences of the brsv l gene, and its encoded protein, with sequences of the l gene and protein of human respiratory syncytial virus strain a2 showed 77% identity at the nucleotide l ... | 1998 | 9747733 |
| matrix protein gene nucleotide and predicted amino acid sequence demonstrate that the first us avian pneumovirus isolate is distinct from european strains. | avian pneumovirus (apv) is the etiological agent of turkey rhinotracheitis (trt). outbreaks of trt first occurred in the us during may, 1996 and continued through june, 1997. this is the first report of these virus types in the us that was previously considered exotic to the us and canada. the us isolate, apv/co, was replicated in chick embryo fibroblasts (cef) and poly-a rna from apv/co infected cef cells was purified for cdna synthesis. degenerate oligonucleotide primers were used to amplify n ... | 1998 | 9879761 |
| turkey rhinotracheitis virus isolated from broiler chicken with swollen head syndrome in japan. | turkey rhinotracheitis (trt) virus was first isolated from a commercial broiler chicken with swollen head syndrome (shs) in japan. at the same time, newcastle disease virus (ndv), infectious bronchitis virus (ibv), avian reovirus (arv), escherichia coli (e.coli), morganella morganii, and proteus mirabilis were also isolated from the same broiler chicken. the presence of antibodies to trt virus was confirmed in the sera of 34-day-old chickens of the flock with shs, however the antibodies to trt v ... | 1995 | 8593307 |
| towards the routine application of nucleic acid technology for avian disease diagnosis. | the use of nucleic acid technology (polymerase chain reaction, probing, restriction fragment analysis and nucleotide sequencing) in the study of avian diseases has largely been confined to fundamental analysis and retrospective studies. more recently these approaches have been applied to diagnosis and what one might call real-time epidemiological studies on chickens and turkeys. at the heart of these approaches is the identification and characterisation of pathogens based on their genetic materi ... | 1997 | 9276989 |
| viral diseases of the respiratory system. | infectious bronchitis, newcastle disease, infectious laryngotracheitis, avian influenza, and pneumovirus are the viruses that more frequently affect the respiratory tract of chickens. because of the tendency to change its antigenic properties, infectious bronchitis is currently the viral disease present in most poultry producing areas of the world. new serotypes and variant strains are reported in several countries. current commercially available vaccines do not always provide protection against ... | 1998 | 9706079 |
| nucleotide sequence of the matrix protein gene of a subgroup b avian pneumovirus. | the nucleotide sequence of the gene encoding the matrix protein of a subgroup b avian pneumovirus has been determined. the gene shows 73.5% homology with that of a subgroup a virus, with most differences occurring in the third codon position. comparison with pneumovirus matrix proteins shows that the apv matrix protein retains the hydrophobic domain common to the others. the analysis indicates that the matrix protein gene can be used to differentiate the two apv subgroups. | 1996 | 8879134 |
| presence of avian pneumovirus type a in continental europe during the 1980s. | three isolates of avian pneumovirus (apv) were isolated in germany during 1987 and 1988 from turkeys with clinical signs of turkey rhinotracheitis and one was isolated during 1990 from a broiler breeder flock with typical signs of swollen head syndrome. the isolates were typed using type-specific reverse transcriptase-polymerase chain reactions. the three isolates from turkeys were identified as type a, while the isolate from the broiler breeders was type b. during the late 1980s no apv live-vir ... | 2000 | 11075551 |
| isolation of an avian pneumovirus from broiler chickens. | | 1994 | 8017018 |
| extensive sequence variation in the attachment (g) protein gene of avian pneumovirus: evidence for two distinct subgroups. | the putative attachment protein of the avian pneumovirus that causes turkey rhinotracheitis is, by analogy with mammalian pneumoviruses, expected to be the major antigenic determinant. we report the nucleotide sequence of the attachment (g) protein genes of five different continental european isolates and compare them with the previously published sequence of the g gene for the focal variant of a u.k. isolate. the nucleotide sequences and the predicted amino acid sequences indicate that there ar ... | 1994 | 7964599 |
| sequence of the nucleocapsid protein gene of subgroup a and b avian pneumoviruses. | the nucleocapsid protein (n) gene of two subgroup a and one subgroup b strains of avian pneumovirus has been cloned and sequenced. the gene of all three isolates comprised 1197 nucleotides (nt), which formed a single major open reading frame, potentially encoding a protein of 391 amino acid residues. the n gene of the two subgroup a isolates differed by only 1 nt but differed by 282 (24%) nt and 35 (11%) amino acids from the b isolate. the predicted protein was identical in length to that of hum ... | 1996 | 8738178 |
| sequence and in vitro expression of the phosphoprotein gene of avian pneumovirus. | the phosphoprotein (p) gene of two subgroup a strains of avian pneumovirus comprised 855 nucleotides containing only one substantial open reading frame encoding a protein of 278 amino acids, with a predicted m(r) of 30,323. in vitro translation of p mrna in a wheat germ system resulted in the synthesis of two polypeptides of m(r) 35,000. comparison of the deduced p protein sequence with that of the known mammalian pneumoviruses revealed overall amino acid identities ranging from 31 to 34.5%, sug ... | 1995 | 7653102 |
| immuno-gold labelling of turkey rhinotracheitis virus. | the morphology and morphogenesis of five viruses isolated in great britain, france and south africa from turkeys with rhinotracheitis were examined. the five isolates were antigenically related by immunofluorescence and were indistinguishable by negative contrast and thin section electron microscopy. negative contrast electron microscopy of infected vero cell cultures revealed ortho- or paramyxovirus-like particles and helical nucleocapsids 14 nm in diameter with a pitch of 6 nm. the viral natur ... | 1992 | 1414097 |
| fusion protein predicted amino acid sequence of the first us avian pneumovirus isolate and lack of heterogeneity among other us isolates. | avian pneumovirus (apv) was first isolated from turkeys in the west-central us following emergence of turkey rhinotracheitis (trt) during 1996. subsequently, several apv isolates were obtained from the north-central us. matrix (m) and fusion (f) protein genes of these isolates were examined for sequence heterogeneity and compared with european apv subtypes a and b. among us isolates the m gene shared greater than 98% nucleotide sequence identity with only one nonsynonymous change occurring in a ... | 2000 | 10725547 |
| isolation of avian pneumovirus from an outbreak of respiratory illness in minnesota turkeys. | antibodies to avian pneumovirus (apv) were first detected in minnesota turkeys in 1997. virus isolation was attempted on 32 samples (28 tracheal swabs, 4 pools of trachea and turbinates) that were positive for apv by reverse transcriptase polymerase chain reaction (rt-pcr). the cell cultures used were chicken embryo fibroblast (cef), vero cells, and qt-35 cells. five virus isolates were obtained from these samples, and the identity of the isolates was confirmed by rt-pcr. four isolates were obta ... | 2000 | 10730950 |
| experimental and serologic observations on avian pneumovirus (apv/turkey/colorado/97) infection in turkeys. | an avian pneumovirus (apv) was isolated from commercial turkeys in colorado (apv/colorado) showing clinical signs of a respiratory disease. the results of virus neutralization and indirect fluorescent antibody tests showed that the apv/colorado was partially related to apv subgroup a but was unrelated to apv subgroup b. turkeys experimentally inoculated with the apv/colorado were observed for signs, lesions, seroconversion, and virus shedding. thirty-six 7-wk-old turkeys were distributed into th ... | 2000 | 10737640 |
| avian pneumovirus infection in minnesota turkeys: experimental reproduction of the disease. | avian pneumovirus (apv) is an emerging viral respiratory disease agent of turkeys in minnesota. clinical signs of apv infection include open mouth breathing, ocular and nasal discharge, and swelling of infraorbital sinuses. the virus spreads rapidly among flocks of susceptible turkeys and is associated with increased mortality rates. a flock of 11-wk-old turkeys experienced a respiratory problem characterized by coughing, sneezing, swollen sinuses, and nasal discharge. the reverse transcriptase- ... | 2000 | 10737667 |
| avian rhinotracheitis. | turkey rhinotracheitis, now commonly termed avian pneumovirus (apv) infection, is associated with serious welfare and economic problems in susceptible populations of turkeys and probably also of chickens. the infection principally affects the upper respiratory tract, although egg-laying performance may also be affected in breeding turkeys. secondary infections exacerbate the effects of the primary virus infection. the virus persists for only a short time both in the host and in the environment a ... | 2000 | 10935282 |
| susceptibility of an avian pneumovirus isolated from minnesota turkeys to physical and chemical agents. | survival characteristics of a minnesota avian pneumovirus (apv) isolated from a turkey nasoturbinate, propagated in tissue culture, and exposed to various physiochemical treatments were determined. these characteristics included survivability under various conditions. specifically, apv was viable at temperatures of -70 c and -20 c for over 26 wk, 4 c for less than 12 wk, 20 c for less than 4 wk, 37 c for 48 hr, and 50 c for less than 6 hr. in addition, apv survived 12 freeze/thaw cycles with no ... | 2000 | 10879914 |
| development and evaluation of an enzyme-linked immunosorbent assay for the detection of antibodies to avian pneumovirus. | the development and evaluation of an enzyme-linked immunosorbent assay (elisa) for the detection of antibodies to avian pneumovirus (apv) in chicken or turkey sera is described. the assay was capable of detecting serological responses as early as 11 days after chickens had been experimentally exposed to apv. the assay was evaluated by testing 4989 chicken or turkey sera from canada (a known apv-negative country) and by testing 1190 chicken or turkey sera assumed positive from evidence of other l ... | 1994 | 7702500 |
| specific detection of avian pneumovirus (apv) us isolates by rt-pcr. | this report details the development of an rt-pcr assay for the specific detection of us isolates of avian pneumovirus (apv). of the several primer pairs tested, two sets of primers derived from the matrix gene of apv were able to specifically detect the viral rna of apv. the nucleotide sequence comparison of the pcr products of apv isolates from minnesota suggested that these viruses were closely related to the colorado strain of apv, but were distinct from subtypes a and b european isolates of ... | 2000 | 10948996 |
| absence of antibodies to avian pneumovirus in canadian poultry. | | 1993 | 8456552 |
| duration of cross-protection between subtypes a and b avian pneumovirus in turkeys. | the degree and duration of clinical and virological cross-protection between avian pneumovirus subtypes a and b were examined in two-week-old pneumovirus antibody-free turkeys. the turkeys were inoculated with either a virulent subtype a (belgian isolate a/t6/96), a virulent subtype b (belgian isolate b/t9/96), an attenuated subtype a or an attenuated subtype b, and challenged homologously and heterologously with virulent avian pneumovirus two, five and 11 weeks after inoculation. birds inoculat ... | 2000 | 10958535 |
| avian pneumovirus infections of turkeys and chickens. | avian pneumoviruses (apvs) cause major disease and welfare problems in many areas of the world. in turkeys the respiratory disease and the effect on egg laying performance are clearly defined. however, in chickens, the role of apv as a primary pathogen is less clear, although it is widely believed to be one of the factors involved in swollen head syndrome. the mechanisms of virus transmission over large distances are not understood, but wild birds have been implicated. apv has recently been repo ... | 2000 | 10985803 |
| the ectodomains but not the transmembrane domains of the fusion proteins of subtypes a and b avian pneumovirus are conserved to a similar extent as those of human respiratory syncytial virus. | the fusion glycoprotein (f(b)) gene of five strains of the b subtype of avian pneumovirus (apv; turkey rhinotracheitis virus) has been sequenced. the length of the f(b) protein was 538 amino acids, identical to that of the f protein of subtype a virus, with which it had 74% and 83% overall nucleotide and deduced amino acid identities, respectively. the f(b) and f(a) ectodomains had 90% amino acid identity, very similar to the 91% identity between the ectodomains of the f proteins of subtype a an ... | 1998 | 9634080 |
| rescue of synthetic minireplicons establishes the absence of the ns1 and ns2 genes from avian pneumovirus. | we have determined the nucleotide sequences of the regions 3' and 5' proximal to the avian pneumovirus (apv) n and l genes, respectively. these sequences were used in the construction of a synthetic minireplicon construct in which the chloramphenicol acetyltransferase (cat) reporter gene was flanked at its 3' end with the apv leader together with the apv n gene start signal and at its 5' end with the apv l gene end signal and the genome trailer region. the ability of t7 rna polymerase runoff tra ... | 1997 | 9371659 |
| avian pneumovirus (apv) rna from wild and sentinel birds in the united states has genetic homology with rna from apv isolates from domestic turkeys. | nasal turbinates or swabs were collected from wild ducks, geese, owls, sparrows, swallows, and starlings and from sentinel ducks placed next to turkey farms experiencing avian pneumovirus (apv) infections and were analyzed for apv genome and infectious particles. apv rna was detected in samples examined from geese, sparrows, and starlings. apv rna and antibodies were also detected in two different groups of sentinel ducks. infectious apv was recovered from sentinel duck samples. the apv m gene i ... | 2000 | 11060113 |
| the sensitivity and specificity of a reverse transcription-polymerase chain reaction assay for the avian pneumovirus (colorado strain). | a reverse transcription-polymerase chain reaction (rt-pcr) assay for the detection of avian pneumovirus (apv), colorado strain (us/co), was evaluated for sensitivity and specificity. the single-tube rt-pcr assay utilized primers developed from the matrix (m) gene sequence of the us/co apv. the rt-pcr amplified the us/co apv but did not amplify other pneumoviruses, including the avian pneumoviruses subgroups a and b. the rt-pcr was capable of detecting between 10(0.25) mean tissue culture infecti ... | 2000 | 11007019 |
| nucleotide sequences of the f, l and g protein genes of two non-a/non-b avian pneumoviruses (apv) reveal a novel apv subgroup. | sequence analysis was performed of all or part of the genes encoding the fusion (f), polymerase (l) and attachment (g) proteins of two french non-a/non-b avian pneumovirus (apv) isolates (fr/85/1 and fr/85/2). the two isolates shared at least 99.7% nt and 99.0% aa sequence identity. comparison with the f genes from subgroup a, subgroup b or colorado apvs revealed nt and aa identities of 70.0-80. 5% and 77.6-97.2%, respectively, with the l gene sharing 76.1% nt and 85.3% aa identity with that of ... | 2000 | 11038385 |
| development of a highly sensitive and specific enzyme-linked immunosorbent assay based on recombinant matrix protein for detection of avian pneumovirus antibodies. | the matrix (m) protein of avian pneumovirus (apv) was evaluated for its antigenicity and reliability in an enzyme-linked immunosorbent assay (elisa) for diagnosis of apv infection, a newly emergent disease of turkeys in united states. sera from apv-infected turkeys consistently contained antibodies to a 30-kda protein (m protein). an elisa based on recombinant m protein generated in escherichia coli was compared with the routine apv elisa that utilizes inactivated virus as antigen. of 34 experim ... | 2000 | 11060061 |
| susceptibility of broiler chicks to infection by avian pneumovirus of turkey origin. | in this paper we present the results of studies on the infectivity of an isolate of avian pneumovirus (apv) from turkeys to broiler chickens. two-week-old broiler chicks free of antibodies to apv were exposed either by oculonasal or oral route with a cell cultured apv of turkey origin. chickens from both apv-inoculated groups exhibited clinical signs that included coughing, sneezing, nasal discharge, and watery eyes during 2-8 days postinoculation. tissue samples from birds in the apv-inoculated ... | 2000 | 11195633 |
| a multiplex reverse transcription-polymerase chain reaction assay for newcastle disease virus and avian pneumovirus (colorado strain). | newcastle disease virus (ndv) and avian pneumovirus (apv) cause newcastle disease and rhinotracheitis respectively, in turkeys. both of these viruses infect the respiratory system. a one-tube, multiplex, reverse transcription-polymerase chain reaction (rt-pcr) assay for the detection of both ndv and colorado strain of apv (apv-col) was developed and evaluated. the primers, specific for each virus, were designed from the matrix protein gene of apv-col and the fusion protein gene of ndv to amplify ... | 2000 | 11195650 |
| immunohistochemical detection of avian pneumovirus in formalin-fixed tissues. | an immunohistochemical staining technique (ihc) was developed to detect avian pneumovirus (apv) antigen in formalin-fixed, paraffin-embedded tissue sections using streptavidin-biotin immunoperoxidase staining. samples of nasal turbinates and infraorbital sinuses were collected from 4-week-old poults experimentally inoculated with apv and from older turkeys infected during naturally occurring outbreaks of avian pneumovirus. tissue was fixed in 10% buffered neutral formalin, embedded in paraffin, ... | 2001 | 11243355 |
| a newly discovered human pneumovirus isolated from young children with respiratory tract disease. | from 28 young children in the netherlands, we isolated a paramyxovirus that was identified as a tentative new member of the metapneumovirus genus based on virological data, sequence homology and gene constellation. previously, avian pneumovirus was the sole member of this recently assigned genus, hence the provisional name for the newly discovered virus: human metapneumovirus. the clinical symptoms of the children from whom the virus was isolated were similar to those caused by human respiratory ... | 2001 | 11385510 |
| the clinical, pathological and microbiological outcome of an escherichia coli o2:k1 infection in avian pneumovirus infected turkeys. | the purpose of this study was to evaluate the effect of an escherichia coli infection in avian pneumovirus (apv)-infected turkeys. one group of 2-week-old specific pathogen-free (spf) and two groups of 3-week-old conventional (con) turkeys were inoculated oculonasally with virulent apv subtype a alone, with e. coli o2:k1 alone or with both agents at varying intervals (1, 3, 5 or 7 days) between the two inoculations. the birds were followed clinically and examined for macroscopic lesions at necro ... | 2001 | 11390116 |
| fidelity of leader and trailer sequence usage by the respiratory syncytial virus and avian pneumovirus replication complexes. | the specificity of usage of promoters for replication and transcription by the pneumoviruses human respiratory syncytial virus (hrsv) and avian pneumovirus (apv) was studied using minigenomes containing a reporter gene. when infectious hrsv or apv was used as helper virus, replication could occur only if both the leader and trailer regions (containing the replicative and transcriptional promoters) were derived from the helper virus. in contrast, when the hrsv replication complex was supplied fro ... | 2001 | 11413292 |
| isolation of an avian pneumovirus-like agent from broiler breeder chickens in south africa. | | 1994 | 8085314 |
| isolation of avian pneumovirus in qt-35 cells. | | 1998 | 9854777 |
| a modified enzyme-linked immunosorbent assay for the detection of avian pneumovirus antibodies. | avian pneumovirus (apv) infection of turkeys in minnesota was first confirmed in march 1997. serum samples (n = 5,194) from 539 submissions to minnesota veterinary diagnostic laboratory were tested by a modified enzyme-linked immunosorbent assay (elisa). of these, 2,528 (48.7%) samples from 269 submissions were positive and 2,666 (51.3%) samples from 270 submissions were negative for apv antibodies. most positive samples were from kandiyohi, stearns, morrison, and meeker counties in minnesota. i ... | 2000 | 10907873 |
| detection of antibodies to u.s. isolates of avian pneumovirus by a recombinant nucleocapsid protein-based sandwich enzyme-linked immunosorbent assay. | the nucleocapsid (n) protein of subgroup c (united states-specific) avian pneumovirus (apv/us) was expressed in escherichia coli, and antibodies to the recombinant n protein were shown to specifically recognize the approximately 47-kda n protein of apv/us by western immunoblot analysis. the recombinant apv/us n protein was used in a sandwich-capture enzyme-linked immunosorbent assay (elisa), and the resulting assay was found to be more sensitive and specific than the routine indirect elisa for t ... | 2001 | 11474024 |
| pcr-based detection of an emerging avian pneumovirus in us turkey flocks. | avian pneumovirus (apv) or turkey rhinotracheitis virus (trtv) is an important respiratory pathogen of domesticated poultry in many countries in europe, africa, and asia. until recently, the united states was considered free of apv. in late 1996, an atypical upper respiratory tract infection appeared in turkey flocks in colorado and shortly thereafter in turkey flocks in minnesota. an avian pneumovirus (apv-us) that was serologically distinct from the previously described trtv was isolated as th ... | 2001 | 11482596 |
| serological evidence of avian pneumovirus infection in reared and free-living pheasants. | | 2001 | 11488344 |
| isolation and identification of avian pneumovirus from pheasants. | | 2001 | 11570801 |
| detection of avian pneumovirus in tissues and swab specimens from infected turkeys. | conventional nested and taqman reverse transcription-polymerase chain reaction (rt-pcr) assays for the detection of avian pneumovirus (apv) were evaluated and compared with virus isolation (vi) for sensitivity and specificity. respiratory tissues and tracheal swabs were collected from experimentally inoculated turkeys between 1 and 21 days postinoculation (dpi) and tested by all detection methods. apv was detected by both rt-pcr procedures as early as 1 dpi and as late as 17 dpi, whereas virus w ... | 2001 | 11569730 |
| protective efficacy of high-passage avian pneumovirus (apv/mn/turkey/1-a/97) in turkeys. | a u.s. isolate of avian pneumovirus (apv), apv/mn/turkey/1-a/97, was attenuated by serial cell culture passages in chicken embryo fibroblasts (seven passages) and vero cells (34 passages). this virus was designated as apv passage 41 (p41) and was evaluated for use as a live vaccine in commercial turkey flocks. the vaccine was inoculated by nasal and ocular routes in 2-to-4-wk-old turkeys in 10 turkey flocks, each with 20,000-50,000 birds. only 2 birds per 1000 birds were inoculated in each flock ... | 2001 | 11569731 |
| pathogenic and immunosuppressive effects of avian pneumovirus in turkeys. | avian pneumovirus (apv) causes a respiratory disease in turkeys. the virus has been associated with morbidity and mortality due to secondary infections. our objective was to determine if apv caused immunosuppression in the t-cell or b-cell compartments and to study the pathogenesis of the disease in apv maternal antibody-lacking 2-wk-old commercial turkeys. apv was administered by the eyedrop/intranasal route. observations were made for gross lesions, viral genome, and t-cell mitogenesis and cyt ... | 2002 | 11922327 |
| neonatal avian pneumovirus infection in commercial turkeys. | eleven market turkey flocks developed a respiratory disease characterized by coughing, swollen sinuses and nasal discharge. these symptoms first appeared between 3 and 16 days of age. avian pneumovirus (apv) rna was detected by reverse transcriptase (rt)-polymerase chain reaction (pcr) in six of six flocks tested. apv was detected by immunohistochemistry in turbinates of three of three affected flocks tested. virus isolation attempts were negative. ten of 11 flocks became seropositive on the apv ... | 2002 | 11922343 |
| sequence analysis of the nucleocapsid and phosphoprotein genes of avian pneumoviruses circulating in the us. | avian pneumovirus (apv) has recently been described as the cause of a new respiratory syndrome in turkey flocks in the united states. we here describe the complete sequence of the nucleocapsid (n) and phosphoprotein (p) genes of this emerging apv (apv/us). our results show 59 and 61% nucleotide sequence identity of the apv/us n gene with n genes of previously described european apv subgroups a and b, respectively. the p gene of apv/us showed only 53% nucleotide sequence identity with the ortholo ... | 2001 | 11551642 |
| avian pneumoviruses and emergence of a new type in the united states of america. | avian pneumovirus (apv) primarily causes an upper respiratory disease recognized as turkey rhinotracheitis (trt) or swollen head syndrome (shs) in chickens. the virus was first isolated in south africa during the early 1970s and has subsequently been reported in europe, asia and south america. in february 1997, a serologically distinct apv isolate was officially reported in the usa following an outbreak of trt during the previous year. this was the first report of these virus types in the usa; t ... | 2000 | 11706845 |
| rapid detection of avian pneumovirus in tissue culture by microindirect immunofluorescence test. | an indirect immunofluorescence (ifa) test with a 96-well, flat-bottomed microplate was developed to detect avian pneumovirus (apv) antigen in vero cell cultures. samples of nasal turbinates and swabs from infraorbital sinuses and trachea were collected from 4-week-old poults experimentally inoculated with apv. the apv titers by tissue culture ifa staining were compared with that of visual reading of cytopathic effect (cpe). the ability of ifa staining to detect apv antigen correlated well with v ... | 2002 | 11939343 |
| molecular epidemiology of subgroup c avian pneumoviruses isolated in the united states and comparison with subgroup a and b viruses. | the avian pneumovirus (apv) outbreak in the united states is concentrated in the north-central region, particularly in minnesota, where more outbreaks in commercial turkeys occur in the spring (april to may) and autumn (october to december). comparison of the nucleotide and amino acid sequences of nucleoprotein (n), phosphoprotein (p), matrix (m), fusion (f), and second matrix (m2) genes of 15 u.s. apv strains isolated between 1996 and 1999 revealed between 89 and 94% nucleotide sequence identit ... | 2002 | 11980943 |
| vaccination of turkeys with an avian pneumovirus isolate from the united states. | four-week-old poults obtained from avian pneumovirus (apv) antibody-free parents were vaccinated with different serial 10-fold dilutions of cell culture-propagated apv vaccine. the birds were vaccinated with 50 microl into each conjunctival space and nostril (total of 200 microl). each poult of each group was vaccinated in groups that received doses of 4 x 10(4), 4 x 10(3), 4 x 10(2), 4 x 10(1), or 4 x 10(0) 50% tissue culture infective dose (tcid50) of apv vaccine, respectively. respiratory sig ... | 2001 | 11785871 |
| pathogenesis of avian pneumovirus infection in turkeys. | avian pneumovirus (apv) is the cause of a respiratory disease of turkeys characterized by coughing, ocular and nasal discharge, and swelling of the infraorbital sinuses. sixty turkey poults were reared in isolation conditions. at 3 weeks of age, serum samples were collected and determined to be free of antibodies against apv, avian influenza, hemorrhagic enteritis, newcastle disease, mycoplasma gallisepticum, mycoplasma synoviae, mycoplasma meleagridis, ornithobacterium rhinotracheale, and borde ... | 2002 | 12014494 |
| reduced efficacy of hemorrhagic enteritis virus vaccine in turkeys exposed to avian pneumovirus. | avian pneumovirus (apv) is an immunosuppressive respiratory pathogen of turkeys. we examined the effect of apv infection on the vaccine efficacy of hemorrhagic enteritis virus (hev) vaccines. apv was inoculated in 2-wk-old turkeys. two or four days later, an attenuated hev vaccine (hevp30) or marble spleen disease virus (msdv) vaccine were administered. virulent hev challenge was given 19 days after hev vaccination. apv exposure compromised the ability of hevp30 and msdv to protect turkeys again ... | 2002 | 12061644 |
| experimental infection of turkeys with avian pneumovirus and either newcastle disease virus or escherichia coli. | avian pneumoviruses (apvs) are rna viruses responsible for upper respiratory disease in poultry. experimental infections are typically less severe than those observed in field cases. previous studies with apv and escherichia coli suggest this discrepancy is due to secondary agents. field observations indicate apv infections are more severe with concurrent infection by newcastle disease virus (ndv). in the current study, we examined the role of lentogenic ndv in the apv disease process. two-week- ... | 2002 | 12061652 |
| in vitro effects of some steroidal hormones on the replication of avian pneumovirus. | the effects of testosterone, oestradiol, progesterone and cortisone on the in vitro replication of avian pneumovirus in tracheal organ cultures (toc) were investigated. samples of cell-associated and cell-free virus from toc, grown in medium containing these hormones, were taken at selected intervals. progesterone and cortisone caused a slight increase in cell-associated virus. testosterone and oestradiol caused a slight delay and decrease in virus replication when compared with the controls. al ... | 2002 | 12069273 |
| isolation of avian pneumovirus from mallard ducks that is genetically similar to viruses isolated from neighboring commercial turkeys. | our earlier studies demonstrating avian pneumovirus (apv) rna in wild geese, sparrows, swallows, starlings and mallard ducks suggested that wild birds might be involved in the circulation of apv in the united states. to determine whether turkey virus can be transmitted to the free flying birds, we placed apv-negative mallard ducks next to a turkey farm experiencing a severe apv outbreak and in an area with a large population of waterfowls. the sentinel ducks did not develop clinical apv disease ... | 2002 | 11864753 |
| infectious agents associated with respiratory disease in pheasants. | in a case-control study of the infectious agents associated with natural outbreaks of respiratory disease in pheasants, 28 batches of birds from sites affected by disease and eight batches of birds from unaffected sites were examined by six veterinary laboratories in england, wales and scotland, and tested for mycoplasmas, other bacteria and viruses. sinusitis was the commonest sign of disease and was associated with mycoplasma gallisepticum as detected by pcr in the trachea (p < 0.05) and conju ... | 2002 | 12054135 |
| antigenic cross-reactivity among avian pneumoviruses of subgroups a, b, and c at the matrix but not nucleocapsid proteins. | earlier findings from our laboratory based on analysis of nucleotide and predicted amino acid sequence identities of 15 avian pneumoviruses (apvs) isolated from the united states (subgroup c) demonstrated that the viruses were phylogenetically separated from the european subgroup a and subgroup b viruses. here, we investigated whether viruses from the three subgroups were cross-reactive by testing field sera positive for each of the apv subgroups in an enzyme-linked immunosorbent assay (elisa) t ... | 2002 | 12243541 |
| a single subtype of avian pneumovirus circulates among minnesota turkey flocks. | the recent emergence of avian pneumovirus (apv) infection among us turkey flocks has resulted in a major economic threat to the turkey industry. in order to elucidate the molecular epidemiology of apv, comparative sequence analysis of the fusion (f) protein gene of apv was performed for 3 cell culture-adapted isolates and 10 apv positive clinical samples recovered from us turkey flocks. relatively modest levels of nucleotide and amino acid sequence divergence were identified, suggesting the prev ... | 2002 | 12296387 |
| efficacy of avian pneumovirus vaccines against an avian pneumovirus/escherichia coli o2:k1 dual infection in turkeys. | the clinical, pathological and microbiological outcome of a challenge with avian pneumovirus (apv) and escherichia coli o2:k1 was evaluated in turkeys vaccinated with an attenuated apv vaccine and with or without maternally derived antibodies. two groups of two-week-old poults, one with and one without maternally derived antibodies against apv, were vaccinated oculonasally with attenuated apv subtype a or b. a third group remained unvaccinated. eleven weeks later, the turkeys were inoculated int ... | 2002 | 11936883 |
| no effect of turkey herpesvirus infections on the outcome of avian pneumovirus infections in turkeys. | to determine whether turkey herpesvirus (hvt) impairs the aspecific and specific defense against an avian pneumovirus (apv) infection, specific-pathogen-free turkeys were inoculated at 7 days of age with hvt and 1, 5, or 7 wk later with apv. clinical signs, apv replication, and development of antibodies against apv were evaluated. no differences were found between the birds that received both hvt and apv and those that received only apv. | 2001 | 11417838 |
| plaque assay for avian metapneumovirus using a japanese quail fibrosarcoma cell line (qt-35). | a plaque assay for detecting, isolating and titrating avian pneumoviruses using a japanese quail fibrosarcoma cell line (qt-35) is described. plaques are produced after application of either an agarose or carboxymethyl-cellulose (cmc) overlay onto cell monolayers infected with representative avian metapneumoviruses which belong to subgroup a, b or c. virus plaques can be easily visualized by light microscopy or after staining. the parameters affecting plaque appearance include: cell seeding conc ... | 2003 | 12445932 |
| detection and differentiation of avian pneumoviruses (metapneumoviruses). | the available detection methods for avian pneumoviruses (turkey rhinotracheitis virus; genus metapneumovirus) in turkeys, domestic fowl and other species are reviewed. the advantages and disadvantages of virus isolation techniques, virus or genome (polymerase chain reaction) detection and serology are discussed. some of the problems likely to be encountered are considered, including the detection of yet to be discovered subtypes, as are the factors that are likely to influence the outcome of the ... | 2002 | 12396356 |
| susceptibility of ducks to avian pneumovirus of turkey origin. | to determine the susceptibility of ducks to avian pneumovirus (apv) of turkey origin. | 2001 | 11453499 |
| experimental and field evaluation of a live vaccine against avian pneumovirus. | the attenuation of an avian pneumovirus (apv) isolate (apv/mn/turkey/1-a/97) by 63 serial passages in cell culture (seven in chicken embryo fibroblasts and 56 in vero cells) and its evaluation as a live attenuated vaccine in turkey poults is described. the birds were vaccinated with two different doses of attenuated virus (10(4.5) median tissue culture infectious dose (tcid(50))/ml and 10(2.5) tcid(50) /ml) at 2 weeks of age, and were challenged 2 weeks later with virulent apv. no clinical signs ... | 2002 | 12396339 |
| detection of avian pneumovirus in wild canada (branta canadensis) and blue-winged teal (anas discors) geese. | choanal cleft swab samples from 770 wild canada geese (branta canadensis) and 358 blue-winged teal (anas discors), captured for relocation or banding, were examined for the presence of avian pneumovirus (apv) rna by reverse transcription (rt)-polymerase chain reaction (pcr) and for virus isolation. the swab samples were pooled into groups of 5 or 10. sixty eight of 102 (66.7%) pooled goose samples were rt-pcr positive for apv rna. thirteen of 52 (25.0%) pooled blue-winged teal samples were rt-pc ... | 2002 | 12495069 |
| regulation of host cell transcriptional physiology by the avian pneumovirus provides key insights into host-pathogen interactions. | infection with a viral pathogen triggers several pathways in the host cell that are crucial to eliminating infection, as well as those that are used by the virus to enhance its replication and virulence. we have here used suppression subtractive hybridization and cdna microarray analyses to characterize the host transcriptional response in an avian pneumovirus model of infection. the results of our investigations reveal a dynamic host response that includes the regulation of genes with roles in ... | 2003 | 12663796 |
| metapneumoviruses in birds and humans. | avian pneumovirus (apv, turkey rhinotracheitis virus) and human metapneumovirus (hmpv) are pathogens of birds and humans, respectively, that are associated with upper respiratory tract infections. based on their different genomic organization and low level of nucleotide (nt) and amino acid (aa) identity with paramyxoviruses in the genus pneumovirus, apv and hmpv have been classified into a new genus referred to as metapneumovirus. first isolated in 1970s, apv strains have since been isolated in ... | 2003 | 12573494 |
| subtype b avian metapneumovirus resembles subtype a more closely than subtype c or human metapneumovirus with respect to the phosphoprotein, and second matrix and small hydrophobic proteins. | avian metapneumovirus (ampv) subtype b (ampv/b) nucleotide sequences were obtained for the phosphoprotein (p), second matrix protein (m2), and small hydrophobic protein (sh) genes. by comparison with sequences from other metapneumoviruses, ampv/b was most similar to subtype a ampv (ampv/a) relative to the us subtype c isolates (ampv/c) and human metapneumovirus (hmpv). strictly conserved residues common to all members of the pneumovirinae were identified in the predicted amino acid sequences of ... | 2003 | 12686426 |
| characterization of avian metapneumoviruses isolated in the usa. | avian pneumovirus (apv; officially known as turkey rhinotracheitis virus) is an emergent pathogen of birds in the usa that results in upper respiratory tract disease in turkeys. six years after the first outbreak in the usa, the disease continues to ravage turkey flocks, primarily in the state of minnesota. from 1997 to 2000, the industry recorded losses estimated at 15 million us dollars per annum. researchers have developed sensitive diagnostic techniques, including the enzyme-linked immunosor ... | 2002 | 12665110 |
| nucleotide and predicted amino acid sequence-based analysis of the avian metapneumovirus type c cell attachment glycoprotein gene: phylogenetic analysis and molecular epidemiology of u.s. pneumoviruses. | a serologically distinct avian metapneumovirus (ampv) was isolated in the united states after an outbreak of turkey rhinotracheitis (trt) in february 1997. the newly recognized u.s. virus was subsequently demonstrated to be genetically distinct from european subtypes and was designated ampv serotype c (ampv/c). we have determined the nucleotide sequence of the gene encoding the cell attachment glycoprotein (g) of ampv/c (colorado strain and three minnesota isolates) and predicted amino acid sequ ... | 2003 | 12682171 |
| deduced amino acid sequence of the small hydrophobic protein of us avian pneumovirus has greater identity with that of human metapneumovirus than those of non-us avian pneumoviruses. | we report here the nucleotide and deduced amino acid (aa) sequences of the small hydrophobic (sh) gene of the avian pneumovirus strain colorado (apv/co). the sh gene of apv/co is 628 nucleotides in length from gene-start to gene-end. the longest orf of the sh gene encoded a protein of 177 aas in length. comparison of the deduced aa sequence of the sh protein of apv/co with the corresponding published sequences of other members of genera metapneumovirus showed 28% identity with the newly discover ... | 2003 | 12727346 |
| sequence analysis of the matrix (m2) protein gene of avian pneumovirus recovered from turkey flocks in the united states. | we here report the comparative sequence and phylogenetic analysis of the avian pneumovirus subgroup c (apv c) matrix (m2) gene of cell culture-adapted isolates and clinical samples. limited heterogeneity was observed among the m2 sequences, suggesting that diagnostic tests and vaccines against apv c are likely to exhibit broad cross-reactivity. | 2003 | 12791921 |
| effect of an immunomodulator on the efficacy of an attenuated vaccine against avian pneumovirus in turkeys. | since 1997, avian pneumovirus (apv) has caused estimated annual losses of $15 million to the minnesota turkey industry. in order to develop an attenuated live vaccine against apv, we serially passaged a minnesota isolate of apv (apv/mn/turkey/1-a/97) in vitro in cell cultures for 41 passages. laboratory experiments with this high-passage virus (p41) indicated that the attenuated virus provided immunogenic protection to turkeys against challenge with virulent apv, although some birds showed mild ... | 2002 | 12243518 |
| pathogenicity, transmissibility, and tissue distribution of avian pneumovirus in turkey poults. | the pathogenicity, transmissibility, tissue distribution, and persistence of avian pneumovirus (apv) in turkey poults were investigated in three experiments. in the first experiment, we inoculated 2-wk-old commercial turkey poults oculonasally with apv alone or in combination with bordetella avium. in the dually infected group, clinical signs were more severe, the virus persisted longer, the bacteria invaded more respiratory tissues, and the birds had higher antibody titer than the group exposed ... | 2002 | 12243529 |
| comparison of enzyme-linked immunosorbent assays and virus neutralization test for detection of antibodies to avian pneumovirus. | two different whole-virus enzyme-linked immunosorbent assays (elisas), developed in ohio (oh) with apv/minnesota/turkey/2a/97 and in minnesota (mn) with apv/colorado/turkey/97, and the virus neutralization (vn) test were used to test 270 turkey serum samples from 27 minnesota turkey flocks for avian pneumovirus (apv) antibodies. in addition, 77 turkey serum samples and 128 ostrich serum samples from ohio were tested. none of the turkey samples from ohio had antibodies to apv by the vn test and o ... | 2002 | 12243535 |
| transcriptional analysis of the response of poultry species to respiratory pathogens. | respiratory tract diseases are the single most important cause of economic loss due to infections among poultry populations worldwide. however, the molecular mechanisms of the host response to infections remain unknown. here, we review the literature and describe the adoption of a conceptually simple approach to understand the genetic and biochemical responses of host cells during infection with respiratory pathogens, such as avian pneumovirus (apv). the strategy that we have adopted integrates ... | 2003 | 12817442 |
| presence of avian pneumovirus subtypes a and b in japan. | four avian pneumovirus (apv) isolates from chickens clinically diagnosed with swollen head syndrome were genetically characterized as to the subtypes of the virus in japan. the results of reverse transcriptase-polymerase chain reactions based on subtype-specific primers and direct sequence analysis of g genes indicated subtypes a and b but not c or d of apv were present in japan. several routes or sources are conceivable for apv to invade into japan. | 2003 | 12887210 |
| subgroup c avian metapneumovirus (mpv) and the recently isolated human mpv exhibit a common organization but have extensive sequence divergence in their putative sh and g genes. | the genes encoding the putative small hydrophobic (sh), attachment (g) and polymerase (l) proteins of the colorado isolate of subgroup c avian pneumovirus (apv) were entirely or partially sequenced. they all included metapneumovirus (mpv)-like gene start and gene end sequences. the deduced colorado sh protein shared 26.9 and 21.7 % aa identity with its counterpart in human mpv (hmpv) and apv subgroup a, respectively, but its only significant aa similarities were to hmpv. conserved features inclu ... | 2003 | 12867649 |
| avian pneumovirus and its survival in poultry litter. | the survival of avian pneumovirus (apv) in turkey litter was studied at different temperature (room temperature, [approximately 22-25 c], 8 c, and -12 c) conditions. built-up turkey litter from a turkey breeder farm known to be free of apv was obtained and was divided into two portions. one portion was sterilized by autoclaving and the other portion was kept nonautoclaved. both samples were inoculated with a vero cell-propagated minnesota isolate of apv subtype c (apv/mn2a) with a titer of 10(5) ... | 2003 | 14562910 |
| avian metapneumovirus excretion in vaccinated and non-vaccinated specified pathogen free laying chickens. | vaccinated and non-vaccinated specified pathogen-free white leghorn laying chickens were challenged at peak of lay by the intravenous or oculonasal route with a virulent avian metapneumovirus (ampv) subtype b chicken strain. severe clinical signs and a drop in egg production were induced in the non-vaccinated intravenously challenged birds whereas the vaccinates were not affected. live virus excretion was demonstrated in the faeces and respiratory tract of non-vaccinated hens for up to 7 days po ... | 2004 | 14681066 |
| immunity to avian pneumovirus infection in turkeys following in ovo vaccination with an attenuated vaccine. | fertile turkey eggs after 24 days of incubation were vaccinated in ovo with a commercial live attenuated subtype a avian pneumovirus (apv) vaccine. hatchability was not adversely affected. when a high dose (10 times maximum commercial dose) of vaccine was tested in maternal antibody negative (ma-) eggs, mild clinical signs developed in a small proportion of the poults for 1-4 days only. post-vaccination antibody titres at 3 weeks of age were significantly higher than those seen when the same dos ... | 2003 | 12615430 |
| cold adapted avian pneumovirus for use as live, attenuated vaccine in turkeys. | we report the development of a cold adapted strain of avian pneumovirus (apv) and its evaluation as a live vaccine candidate in 2-week-old turkey poults. a us isolate of apv (apv/mn/turkey/1-a/97) was serially passaged in vero cells for 41 passages and then adapted to grow at sub-optimal temperatures by growing successively at 35, 33 and 31 degrees c for eight passages at each temperature. the virus thus adapted to grow at 31 degrees c was used as a candidate vaccine. the birds were vaccinated w ... | 2003 | 12615432 |
| lack of antigenic relationships between avian pneumovirus and four avian paramyxoviruses. | avian paramyxoviruses (pmvs) and avian pneumovirus (apv) belong to the family paramyxoviridae. antigenic relationships between pmvs were shown previously, hence, this study was designed to investigate possible antigenic relationships between apv and four avian pmvs (pmv-1, pmv-2, pmv-3, and pmv-7). enzyme-linked immunosorbent assay (elisa), hemagglutination inhibition (hi) test, and virus neutralization (vn) test in chicken embryos and in vero cells were used. the hi test was performed with the ... | 2003 | 12713174 |
| sequence polymorphism of the predicted human metapneumovirus g glycoprotein. | the putative g glycoprotein genes of 25 human metapneumovirus (hmpv) field isolates obtained during five consecutive epidemic seasons (1997 to 2002) were sequenced. sequence alignments identified two major genetic groups, designated groups 1 and 2, and two minor genetic clusters within each major group, designated subgroups a and b. extensive nucleotide and deduced amino acid sequence variability was observed, consisting of high rates of nucleotide substitutions, use of alternative transcription ... | 2004 | 14993653 |
| immunization of turkeys with a dna vaccine expressing either the f or n gene of avian metapneumovirus. | in this study we compared protection by dna vaccination with the f (pcmv-f) or n (pcmv-n) gene from avian metapneumovirus (ampv) in turkeys. one-week-old turkey poults received two intramuscular injections 2 wk apart. birds were challenged with a turkey-embryo-adapted ampv at 5 wk of age. birds vaccinated with pcmv-f had decreased clinical signs of disease as well as significantly reduced virus load in tracheal swabs compared with birds vaccinated with pcmv-n or unvaccinated control birds. serum ... | 2003 | 14708985 |
| development of a nucleoprotein-based enzyme-linked immunosorbent assay using a synthetic peptide antigen for detection of avian metapneumovirus antibodies in turkey sera. | avian metapneumoviruses (ampv) cause an upper respiratory tract disease with low mortality but high morbidity, primarily in commercial turkeys, that can be exacerbated by secondary infections. there are three types of ampv, of which type c is found only in the united states. the ampv nucleoprotein (n) amino acid sequences of serotypes a, b, and c were aligned for comparative analysis. on the basis of the predicted antigenicity of consensus sequences, five ampv-specific n peptides were synthesize ... | 2004 | 15013970 |
| effects of bacterial coinfection on the pathogenesis of avian pneumovirus infection in turkeys. | four- and nine-week-old poults were inoculated with cell culture propagated avian pneumovirus (apv) into each conjunctival space and nostril, followed by inoculation 3 days later with escherichia coli, bordetella avium (ba), or ornithobacterium rhinotracheale or a mixture of all three (ebo). clinical signs were evaluated on days 3, 5, 7, 9, 11, and 14 postinoculation (pi) of apv. the poults were euthanatized on days 2, 4, 6, 10, and 14 pi, and blood and tissues were collected. the poults that re ... | 2004 | 15077796 |
| cold-adapted strain of avian pneumovirus as a vaccine in one-day-old turkeys and the effect of inoculation routes. | to determine the optimum route of vaccination, we inoculated 1-day-old turkeys with a cold-adapted strain of avian pneumovirus (apv) by oculonasal, oral, or aerosol route. another two groups served as nonvaccinated-challenged and nonvaccinated-nonchallenged groups. birds in all vaccinated and nonvaccinated-challenged groups were challenged with virulent apv 3 wk postvaccination. after challenge, no vaccinated bird developed clinical signs or virus shedding, whereas nonvaccinated-challenged birds ... | 2004 | 15077809 |
| detection of three avian respiratory viruses by single-tube multiplex reverse transcription-polymerase chain reaction assay. | acute respiratory tract infections are leading causes of morbidity in poultry farms throughout the world. avian pneumovirus (apv), avian influenza virus (aiv), and newcastle disease virus (ndv) have been recognized as the most important pathogens of both chicken and turkeys. single-virus reverse transcription-polymerase chain reaction (srt-pcr) assays are used extensively to detect these viruses in clinical samples. this study reports the development and evaluation of a single-tube multiplex rt- ... | 2004 | 15152843 |
| animal pneumoviruses: molecular genetics and pathogenesis. | pneumoviruses are single-stranded, negative-sense, nonsegmented rna viruses of the family paramyxoviridae, subfamily pneumovirinae, and include pathogens that infect humans (respiratory syncytial virus and human metapneumovirus), domestic mammals (bovine, ovine, and caprine respiratory syncytial viruses), rodents (pneumonia virus of mice), and birds (avian metapneumovirus). among the topics considered in this review are recent studies focused on the roles of the individual virus-encoded componen ... | 2004 | 15084507 |
| microwave or autoclave treatments destroy the infectivity of infectious bronchitis virus and avian pneumovirus but allow detection by reverse transcriptase-polymerase chain reaction. | a method is described for enabling safe transit of denatured virus samples for polymerase chain reaction (pcr) identification without the risk of unwanted viable viruses. cotton swabs dipped in avian infectious bronchitis virus (ibv) or avian pneumovirus (apv) were allowed to dry. newcastle disease virus and avian influenza viruses were used as controls. autoclaving and microwave treatment for as little as 20 sec destroyed the infectivity of all four viruses. however, both ibv and apv could be d ... | 2004 | 15223557 |