| inhibition of interferon-mediated antiviral responses by influenza a viruses and other negative-strand rna viruses. | | 2001 | 11162793 |
| serological monitoring on layer farms with specific pathogen-free chickens. | to monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (spf) chickens were introduced into two layer farms and reared with laying hens for 12 months. spf chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. as a result, antibodies to eight or ten kinds of pathogens were detected in spf chickens on each farm. antibodies to infectious bronchitis virus (ibv), avian nephritis virus, mycoplasma galli ... | 2000 | 11193353 |
| 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 |
| lack of antigenic relationship between french and recent north american non-a/non-b turkey rhinotracheitis viruses. | twelve turkey rhinotracheitis viruses (trtvs) including the colorado isolate and two french non-a/non-b viruses were serologically compared. six enzyme-linked immunosorbent assay (elisa) antigens derived from subgroup a, subgroup b, a french non-a/non-b, and the colorado trtvs were used. virus neutralization (vn) tests were performed with four ma-104-adapted viruses derived from subgroup a, subgroup b, a french non-a/non-b, and the colorado viruses. french strains isolated since 1995 were assign ... | 2000 | 11195657 |
| 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 |
| neonatal syncytial giant cell hepatitis with paramyxoviral-like inclusions. | syncytial giant cell hepatitis in the neonatal period has been associated with many different etiologic agents and may present initially as cholestasis. infectious causes are most common and include: (1 ) generalized bacterial sepsis, (2) viral agents, (3) toxoplasmosis, (4) syphilis, (5) listeriosis, and (6) tuberculosis. viral hepatitis may be due to cytomegalovirus, rubella virus, herpes simplex, hhv-6, varicella, coxsackievirus, echovirus, reovirus 3, parvovirus b19, hiv, enteroviruses, para ... | 2001 | 11297322 |
| multicentered study of viral acute lower respiratory infections in children from four cities of argentina, 1993-1994. | this study describes the first multicentered study of acute lower respiratory infection viral etiology in young children from four different geographical areas of argentina. a total of 1,278 children under 5 years of age, hospitalized in primary care centers from buenos aires, córdoba, santa fé and mar del plata cities during a 2-year period were studied (1993-1994). nasopharyngeal aspirates were investigated for respiratory syncytial virus (rsv), adenovirus, parainfluenza, and influenza a and b ... | 2001 | 11360249 |
| 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 |
| 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 |
| susceptibility of ducks to avian pneumovirus of turkey origin. | to determine the susceptibility of ducks to avian pneumovirus (apv) of turkey origin. | 2001 | 11453499 |
| 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 |
| pulmonary tumors in germfree mice: induction with urethan. | | 1970 | 11515033 |
| chimeric bovine respiratory syncytial virus with attachment and fusion glycoproteins replaced by bovine parainfluenza virus type 3 hemagglutinin-neuraminidase and fusion proteins. | chimeric bovine respiratory syncytial viruses (brsv) expressing glycoproteins of bovine parainfluenza virus type 3 (bpiv-3) instead of brsv glycoproteins were generated from cdna. in the brsv antigenome cdna, the open reading frames of the major brsv glycoproteins, attachment protein g and fusion protein f, were replaced individually or together by those of the bpiv-3 hemagglutinin-neuraminidase (hn) and/or fusion (f) glycoproteins. recombinant virus could not be recovered from cdna when the brs ... | 2001 | 11533200 |
| 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 |
| 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 |
| isolation and identification of avian pneumovirus from pheasants. | | 2001 | 11570801 |
| identification and molecular characterization of 18 paramyxoviruses isolated from snakes. | viral agents from 18 different snake species (families colubridae, viperidae, and crotalidae) showing respiratory symptoms and neuronal disease were identified as paramyxoviruses by typical cytopathogenic effect (cpe), electron microscopy, and hemagglutination inhibition. detailed molecular characterization of the viruses was performed by partial l- and f-gene-specific reverse transcription polymerase chain reaction (rt-pcr) and sequencing, nucleotide and amino acid sequence alignment, and phylo ... | 2001 | 11597749 |
| gene expression in epithelial cells in response to pneumovirus infection. | respiratory syncytial virus (rsv) and pneumonia virus of mice (pvm) are viruses of the family paramyxoviridae, subfamily pneumovirus, which cause clinically important respiratory infections in humans and rodents, respectively. the respiratory epithelial target cells respond to viral infection with specific alterations in gene expression, including production of chemoattractant cytokines, adhesion molecules, elements that are related to the apoptosis response, and others that remain incompletely ... | 2001 | 11686888 |
| eosinophils, eosinophil ribonucleases, and their role in host defense against respiratory virus pathogens. | eosinophils remain among the most enigmatic of cells, as our appreciation of their detrimental activities--e.g., asthma and allergic disease--far outweighs our understanding of their beneficial effects. among the major secretory effector proteins of eosinophils are the ribonucleases eosinophil-derived neurotoxin (edn) and eosinophil cationic protein (ecp) in primates and their orthologs, the eosinophil-associated ribonucleases (ears) in rodents. the rapid diversification observed among these rib ... | 2001 | 11698487 |
| 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 |
| glucocorticoid administration accelerates mortality of pneumovirus-infected mice. | the use of glucocorticoids for the treatment of symptoms associated with respiratory syncytial virus (rsv) infection has been questioned. to evaluate the sequelae of glucocorticoid administration in the setting of pneumovirus infection in vivo, hydrocortisone was administered to mice infected with pneumonia virus of mice (pvm), a pneumovirus and natural rodent pathogen that is closely related to rsv and replicates the signs and symptoms of severe human rsv infection. results showed that hydrocor ... | 2001 | 11740726 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| differential expression of proinflammatory cytokine genes in vivo in response to pathogenic and nonpathogenic pneumovirus infections. | pneumonia virus of mice (pvm; paramyxoviridae, subfamily pneumovirinae) is an important pathogen for the study of physiologically relevant acute inflammatory responses in rodent hosts. in contrast to the severe symptomatology observed in response to infection with pvm strain j3666, infection with strain 15 resulted in few clinical symptoms, limited cellular inflammatory response, and no production of macrophage inflammatory protein-1alpha or monocyte chemoattractant peptide (mcp)-1. microarray a ... | 2002 | 12089656 |
| 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 |
| 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 |
| response of pheasants to live attenuated turkey rhinotracheitis vaccine. | the entire crop of 18,120 pheasants for the 2000 rearing season (may 8 to august 7) of one estate in the south of england was vaccinated at one day and five weeks of age with a turkey rhinotracheitis (trt) vaccine. blood samples and oropharyngeal swabs were taken from the second week's hatching every three weeks throughout the growing season to assess the response of the birds. there was evidence of seroconversion in samples collected three weeks after vaccination, with positive titres being mai ... | 2002 | 12371689 |
| 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 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 |
| replication and clearance of respiratory syncytial virus: apoptosis is an important pathway of virus clearance after experimental infection with bovine respiratory syncytial virus. | human respiratory syncytial virus is an important cause of severe respiratory disease in young children, the elderly, and in immunocompromised adults. similarly, bovine respiratory syncytial virus (brsv) is causing severe, sometimes fatal, respiratory disease in calves. both viruses are pneumovirus and the infections with human respiratory syncytial virus and brsv have similar clinical, pathological, and epidemiological characteristics. in this study we used experimental brsv infection in calves ... | 2002 | 12466134 |
| 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 |
| altered pathogenesis of severe pneumovirus infection in response to combined antiviral and specific immunomodulatory agents. | we report here the responses of mice with symptomatic pneumovirus infection to combined antiviral and specific immunomodulatory agents. mice infected with pneumonia virus of mice, a natural mouse pathogen that replicates the signs and symptoms of severe infection with respiratory syncytial virus (rsv), responded to the antiviral agent ribavirin when it was administered in the setting of endogenous (gene deletion) or exogenous (antibody-mediated) blockade of the mip-1alpha proinflammatory signali ... | 2003 | 12502841 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| identification of amino acids that are critical to the processivity function of respiratory syncytial virus m2-1 protein. | the m2-1 protein of respiratory syncytial virus (rsv) is a transcription processivity factor that is essential for virus replication. the function of rsv m2-1 protein can be examined by using an rsvlacz minigenome assay in vitro since the expression of the lacz gene is dependent on m2-1. the m2-1 protein of pneumonia virus of mice (pvm), also a member of the pneumovirus genus, functions poorly in the rsvlacz minigenome assay despite conservation of the cys(3)-his(1) motif at its n terminus and a ... | 2003 | 12692207 |
| seroprevalence of human metapneumovirus in japan. | a new human pneumovirus, provisionally designated human metapneumovirus, was discovered by dutch researchers. we examined 142 serum samples from the general population aged from 1 month to 35 years in japan for human metapneumovirus antibody by indirect immunofluorescence assays using human metapneumovirus-infected monkey kidney cells. the overall prevalence of human metapneumovirus infection was 72.5%. the seropositive rate was lowest in the age group of 6 months to 1 year and gradually increas ... | 2003 | 12696118 |
| 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 |
| 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 |
| profilin is required for viral morphogenesis, syncytium formation, and cell-specific stress fiber induction by respiratory syncytial virus. | actin is required for the gene expression and morphogenesis of respiratory syncytial virus (rsv), a clinically important pneumovirus of the paramyxoviridae family. in hep-2 cells, rsv infection also induces actin stress fibers, which may be important in the immunopathology of the rsv disease. profilin, a major regulator of actin polymerization, stimulates viral transcription in vitro. thus, we tested the role of profilin in rsv growth and rsv-actin interactions in cultured cells (ex vivo). | 2003 | 12740026 |
| detection of sendai virus and pneumonia virus of mice by use of fluorogenic nuclease reverse transcriptase polymerase chain reaction analysis. | sendai virus may induce acute respiratory tract disease in laboratory mice and is a common contaminant of biological materials. pneumonia virus of mice (pvm) also infects the respiratory tract and, like sendai virus, may induce a persistent wasting disease syndrome in immunodeficient mice. reverse transcriptase-polymerase chain reaction (rt-pcr) assays have proven useful for detection of sendai virus and pvm immunodeficient animals and contaminated biomaterials. fluorogenic nuclease rt-pcr assay ... | 2003 | 12784851 |
| 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 |
| 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 |
| 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 |
| 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 |
| development and evaluation of a blocking enzyme-linked immunosorbent assay for detection of avian metapneumovirus type c-specific antibodies in multiple domestic avian species. | the first cases of infection caused by avian metapneumoviruses (ampvs) were described in turkeys with respiratory disease in south africa during 1978. the causative agent was isolated and identified as a pneumovirus in 1986. ampvs have been detected in domestic nonpoultry species in europe, but tests for the detection of these viruses are not available in the united states. to begin to understand the potential role of domestic ducks and geese and wild waterfowl in the epidemiology of ampv, we ha ... | 2003 | 12904358 |
| diminished expression of an antiviral ribonuclease in response to pneumovirus infection in vivo. | the mouse eosinophil-associated ribonucleases (mears) are species specific, divergent orthologs of the human antiviral rnase a ribonucleases, eosinophil-derived neurotoxin (rnase 2) and eosinophil cationic protein (rnase 3). we show here that mear 2 is also an antiviral ribonuclease, as micromolar concentrations promote a approximately sixfold reduction in the infectivity of pneumonia virus of mice (pvm) for target respiratory epithelial cells in vitro. although initially identified as a compone ... | 2003 | 12927308 |
| chimeric pneumovirus nucleocapsid (n) proteins allow identification of amino acids essential for the function of the respiratory syncytial virus n protein. | the nucleocapsid (n) protein of the pneumovirus respiratory syncytial virus (rsv) is a major structural protein which encapsidates the rna genome and is essential for replication and transcription of the rsv genome. the n protein of the related virus pneumonia virus of mice (pvm) is functionally unable to replace the rsv n protein in a minigenome replication assay. using chimeric proteins, in which the immediate c-terminal part of the rsv n protein was replaced with the equivalent region of the ... | 2003 | 13679601 |
| seroprevalence of avian pneumovirus in minnesota turkeys. | avian pneumovirus (apv) causes respiratory tract infection in turkeys and was first seen in the united states in colorado in late 1996. in early 1997, the disease was recognized in minnesota and caused estimated losses of up to 15 million dollars per year. this virus has not been reported in the other turkey producing states. we here report the seroprevalence of apv in minnesota from august 1998 to july 2002. the average rate of seroprevalence has been 36.3% (range = 14.2%-64.8%). a seasonal bia ... | 2003 | 14562899 |
| 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 |
| 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 |
| human respiratory syncytial virus matrix protein is an rna-binding protein: binding properties, location and identity of the rna contact residues. | the human respiratory syncytial virus (hrsv) matrix (m) protein is a structural internal membrane protein. here we have shown that, like its orthomyxovirus and rhabdovirus counterparts, it has rna-binding capacity, as determined by retardation of (32)p-labelled riboprobes in gel electrophoresis, cross-linking with uv light and northern-western assays. its binding to rna was neither sequence-specific nor showed a length requirement, although it had cooperative kinetics with a k(d) of 25 nm and pr ... | 2004 | 14993657 |
| respiratory syncytial virus, pneumonia virus of mice, and influenza a virus differently affect respiratory allergy in mice. | respiratory viral infections in early childhood may interact with the immune system and modify allergen sensitization and/or allergic manifestations. in mice, respiratory syncytial virus (rsv) infection during allergic provocation aggravates the allergic t helper (th) 2 immune response, characterized by the production of il-4, il-5, and il-13, and inflammatory infiltrates. however, it is unclear whether the rsv-enhanced respiratory allergic response is a result of non-specific virus-induced dama ... | 2004 | 15005745 |
| control of nonsegmented negative-strand rna virus replication by sirna. | our laboratory provided the first proof-of-concept that double-stranded short interfering rna (ds-sirna) can act as potent and specific antiviral agents. designed against specific mrnas of nonsegmented negative-stranded rna (nnr) viruses, sirnas abrogated expression of the corresponding viral proteins, and generated the predicted viral phenotypes. knockdown was demonstrated across different genera: respiratory syncytial virus (rsv), a pneumovirus; vesicular stomatitis virus (vsv), a rhabdovirus; ... | 2004 | 15068877 |
| 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 |
| 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 |
| 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 |
| antigenic and genetic variability of human metapneumoviruses. | human metapneumovirus (hmpv) is a member of the subfamily pneumovirinae within the family paramyxo- viridae. other members of this subfamily, respiratory syncytial virus and avian pneumovirus, can be divided into subgroups on the basis of genetic or antigenic differences or both. for hmpv, the existence of different genetic lineages has been described on the basis of variation in a limited set of available sequences. we address the antigenic relationship between genetic lineages in virus neutral ... | 2004 | 15200856 |
| significance of interactions between escherichia coli and respiratory pathogens in layer hen flocks suffering from colibacillosis-associated mortality. | this study aimed to examine the significance of interactions between escherichia coli and various respiratory pathogens during outbreaks of colibacillosis-associated mortality in layer hen flocks under field conditions. for this purpose, a case-control study involving 20 control flocks with baseline mortality and 20 flocks with increased mortality due to e. coli septicaemia and polyserositis, was conducted. in each colibacillosis flock, blood samples were taken from 20 hens at the onset of clini ... | 2004 | 15223556 |
| 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 |
| functional antagonism of chemokine receptor ccr1 reduces mortality in acute pneumovirus infection in vivo. | we present an antiviral-immunomodulatory therapeutic strategy involving the chemokine receptor antagonist met-rantes, which yields significant survival in the setting of an otherwise fatal respiratory virus infection. in previous work, we demonstrated that infection with the natural rodent pathogen pneumonia virus of mice involves robust virus replication accompanied by cellular inflammation modulated by the cc chemokine macrophage inflammatory protein 1alpha (mip-1alpha). we found that the anti ... | 2004 | 15254170 |
| genetic variability of the g glycoprotein gene of human metapneumovirus. | human metapneumovirus (hmpv) has been associated with respiratory illnesses like those caused by human respiratory syncytial virus (hrsv) infection. similar to other pneumoviruses, genetic diversity has been reported for hmpv. little information is currently available on the genetic variability of the g glycoprotein (g), which is the most variable gene in rsv and avian pneumovirus. the complete nucleotide sequences of the g open reading frame (orf) of 24 canadian hmpv isolates were determined. p ... | 2004 | 15297494 |
| sequence analysis of the large polymerase (l) protein of the us strain of avian metapneumovirus indicates a close resemblance to that of the human metapneumovirus. | the complete nucleotide sequence of the large polymerase (l) protein of the avian metapneumovirus subgroup c strain colorado was determined. the l protein gene of avian pneumovirus colorado isolate (apv-c) was 6173 nucleotides in length from the gene-start to the gene-end and encoded a polypeptide of 2005 amino acids in length. the length of the l protein of apv-c was exactly the same as that of human metapneumovirus (hmpv) and one amino acid longer than the l protein of apv subgroup a. the l pr ... | 2004 | 15325081 |
| nuclear heat shock response and novel nuclear domain 10 reorganization in respiratory syncytial virus-infected a549 cells identified by high-resolution two-dimensional gel electrophoresis. | the pneumovirus respiratory syncytial virus (rsv) is a leading cause of epidemic respiratory tract infection. upon entry, rsv replicates in the epithelial cytoplasm, initiating compensatory changes in cellular gene expression. in this study, we have investigated rsv-induced changes in the nuclear proteome of a549 alveolar type ii-like epithelial cells by high-resolution two-dimensional gel electrophoresis (2de). replicate 2d gels from uninfected and rsv-infected nuclei were compared for changes ... | 2004 | 15479789 |
| development of a reverse-genetics system for avian pneumovirus demonstrates that the small hydrophobic (sh) and attachment (g) genes are not essential for virus viability. | avian pneumovirus (apv) is a member of the genus metapneumovirus of the subfamily pneumovirinae. this study describes the development of a reverse-genetics system for apv. a minigenome system was used to optimize the expression of the nucleoprotein, phosphoprotein, m2 and large polymerase proteins when transfected into vero cells under the control of the bacteriophage t7 promoter. subsequently, cdna was transcribed from the virion rna to make a full-length antigenome, which was also cloned under ... | 2004 | 15483235 |
| duration of immunity produced by a live attenuated vaccine against avian pneumovirus type c. | a recently developed live, attenuated vaccine against avian pneumovirus (apv) was found to be safe and protective in experimental birds. duration of immunity following a single dose of this experimental vaccine in 1-week-old turkey poults is described. two groups each of 60 poults were housed in separate isolation rooms. birds in group one were inoculated oculonasally at 1 week of age with the vaccine. the second group served as a non-vaccinated group and was inoculated with mock-infected cell c ... | 2004 | 15545025 |
| reduced clearance of respiratory syncytial virus infection in a preterm lamb model. | respiratory syncytial virus (rsv) causes significant respiratory disease in children worldwide. for the study of severe rsv disease seen in preterm infants, a suitable animal model is lacking. the novel hypothesis of this study was that preterm lambs are susceptible to bovine rsv (brsv) infection, an analogous pneumovirus with ruminant host specificity, and that there would be age-dependent differences in select rsv disease parameters. during rsv infection, preterm lambs had elevated temperature ... | 2004 | 15555538 |
| transcriptional response of avian cells to infection with newcastle disease virus. | newcastle disease virus (ndv) causes widespread disease in poultry and wild-birds throughout the world. cdna microarray analysis was used to examine the effect of ndv infection on host cell transcription. the results show that ndv infection causes an apparent suppression of the interferon response genes during the early stages of infection. in addition, the results reveal transcriptional silencing of cytoskeletal proteins such as the alpha, beta, and gamma types of actin, and a downregulation of ... | 2005 | 15567039 |
| animal models for studying respiratory syncytial virus infection and its long term effects on lung function. | human respiratory syncytial virus (hrsv) infection causes a spectrum of illnesses ranging from mild infection to life-threatening bronchiolitis and respiratory failure. human studies on the pathogenesis of rsv infection are invaluable, but animal models permit advances with the use of experimental strategies that would be inappropriate in human studies. | 2004 | 15577578 |
| the effect of pooling sera on the detection of avian pneumovirus antibodies using an enzyme-linked immunosorbent assay test. | pooling of samples is a cost-effective approach to estimate disease prevalence and to identify infected individuals. the objective of this study was to evaluate the use of serum pools for the detection of avian pneumovirus infection in turkey flocks by enzyme-linked immunosorbent assay, so that a minimum number of tests can be performed without compromising the sensitivity and specificity of the test. a total of 900 field samples were tested; 20 samples from each of 45 flocks. all samples were t ... | 2004 | 15586563 |
| design, validation, and absolute sensitivity of a novel test for the molecular detection of avian pneumovirus. | this study describes attempts to increase and measure sensitivity of molecular tests to detect avian pneumovirus (apv). polymerase chain reaction (pcr) diagnostic tests were designed for the detection of nucleic acid from an a-type apv genome. the objective was selection of pcr oligonucleotide combinations, which would provide the greatest test sensitivity and thereby enable optimal detection when used for later testing of field materials. relative and absolute test sensitivities could be determ ... | 2004 | 15586577 |
| the pneumonia virus of mice infection model for severe respiratory syncytial virus infection: identifying novel targets for therapeutic intervention. | pneumonia virus of mice (pvm) is the first infection model that replicates features of severe human respiratory syncytial virus (hrsv) disease in the mouse. the pvm model has highlighted the importance of inflammation to the pathogenesis of severe disease, demonstrating that the inflammatory response remains active and acute even when virus replication ceases in response to appropriate antiviral therapy. the fact that the inflammatory response continues and is not completely linked to ongoing vi ... | 2005 | 15626452 |
| expression of recombinant small hydrophobic protein for serospecific detection of avian pneumovirus subgroup c. | the small hydrophobic (sh) gene of the avian pneumovirus (apv) colorado isolate (co), which belongs to subgroup c (apv/c), was expressed with a baculovirus vector. the recombinant sh protein was evaluated as a potential subgroup-specific diagnostic reagent in order to differentiate infections resulting from apv/c from those induced by apv/a, apv/b, and human metapneumovirus (hmpv). when the recombinant baculovirus was used to infect insect cells, a 31- to 38-kda glycosylated form of the sh prote ... | 2005 | 15643005 |
| evidence of avian pneumovirus spread beyond minnesota among wild and domestic birds in central north america. | to detect avian pneumovirus (apv) in central north america, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of apv rna by reverse transcriptase-polymerase chain reaction (rt-pcr), whereas serum samples from domestic turkeys were analyzed for apv antibodies by enzyme-linked immunosorbent assay (elisa). in 2002, the seroprevalence of disease in domestic turkeys in minnesota remained high (42.3% of the flocks). in addition, there is evide ... | 2004 | 15666873 |
| evaluation of five different antigens in enzyme-linked immunosorbent assay for the detection of avian pneumovirus antibodies. | five different antigens were evaluated in enzyme-linked immunosorbent assay (elisa) tests for the detection of avian pneumovirus (apv) antibodies. two of the 5 antigens were prepared from recent apv isolates from minnesota. the 2 older isolates were passage 63 of a strain currently used as a live, attenuated vaccine and a colorado strain isolated for the first time in the united states and currently used in an elisa test. the fifth antigen is based on an apv recombinant n-protein. basic paramete ... | 2005 | 15690946 |
| persistence of mycoplasma gallisepticum in chickens after treatment with enrofloxacin without development of resistance. | the ability of the avian pathogen mycoplasma gallisepticum to persist despite fluoroquinolone treatment was investigated in chickens. groups of specific pathogen free chickens were experimentally infected with m. gallisepticum and treated with enrofloxacin at increasing concentrations up to the therapeutic dose. when m. gallisepticum could no longer be re-isolated from chickens, birds were stressed by inoculation of infectious bronchitis virus or avian pneumovirus. although m. gallisepticum coul ... | 2005 | 15737482 |
| key role of chlamydophila psittaci on belgian turkey farms in association with other respiratory pathogens. | two hundred turkey sera from eight belgian and two french farms were tested for the presence of antibodies against avian pneumovirus (apv), ornithobacterium rhinotracheale (ort), mycoplasma gallisepticum, mycoplasma meleagridis and chlamydophila psittaci. at slaughter, c. psittaci, apv and ort antibodies were detected in 94, 34 and 6.5% of the turkeys, respectively. no antibodies against m. gallisepticum or m. meleagridis were present. additionally, turkeys on three belgian farms were examined f ... | 2005 | 15795081 |