| 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 |
| sequence and in vitro expression of the m2 gene of turkey rhinotracheitis pneumovirus. | negative-stranded virion rna and oligonucleotide primers complementary to fusion (f) protein gene sequences were used to generate cdna clones, revealing that the gene 5'-proximal to the f protein corresponded to the m2 (22k) gene, as in respiratory syncytial (rs) virus. the transcription start signal, gggacaagu, was identical to that of the f and matrix (m) proteins of turkey rhinotracheitis virus (trtv). there were two sequences with the potential to function as transcription termination/poly(a ... | 1992 | 1607858 |
| sequence analysis of the 22k, sh and g genes of turkey rhinotracheitis virus and their intergenic regions reveals a gene order different from that of other pneumoviruses. | the nucleotide and deduced amino acid sequences of three genes of turkey rhinotracheitis virus (trtv) together with the nucleotide sequences of the relevant intergenic regions were determined. the deduced amino acid sequence of one of the genes shows significant identity (42%) to that of the 22k protein of human respiratory syncytial virus (rsv). the trtv 22k gene, like that of rsv, has a second open reading frame, although the amino acid sequence deduced from this reading frame does not show an ... | 1992 | 1629697 |
| cloning and sequencing of the matrix protein (m) gene of turkey rhinotracheitis virus reveal a gene order different from that of respiratory syncytial virus. | several biochemical properties and the sequence of the fusion glycoprotein (f) have indicated that turkey rhinotracheitis virus (trtv) is a pneumovirus, subfamily pneumovirinae of the paramyxoviridae family. as trtv was known to generate polycistronic mrnas, cdna was generated from trtv strain uk/3bv/85-infected vero cell mrnas using an oligonucleotide primer corresponding to a region of the f gene. sequencing of four cdnas revealed that the gene adjacent to the beginning (3' end) of the f gene ... | 1992 | 1733097 |
| deduced amino acid sequence of the fusion glycoprotein of turkey rhinotracheitis virus has greater identity with that of human respiratory syncytial virus, a pneumovirus, than that of paramyxoviruses and morbilliviruses. | the sequence of the fusion (f) glycoprotein of turkey rhinotracheitis virus (trtv) has been deduced from cdna clones derived from oligo(dt)-selected infected cell rna. the protein consists of 538 amino acids, the f2 and f1 subunits containing 102 (including the f2-f1 connecting peptide rrrr) and 436 residues, respectively. each subunit has one potential n-linked glycosylation site. the protein has 38 to 39% amino acid identity with the f protein of respiratory syncytial virus (pneumovirus genus) ... | 1991 | 1990068 |
| failure to detect antibody to turkey rhinotracheitis virus in australian poultry flocks. | | 1990 | 2121127 |
| an improved elisa and serum neutralisation test for the detection of turkey rhinotracheitis virus antibodies. | the development of a double-well elisa test for the detection of turkey rhinotracheitis (trt) virus antibody in turkey and chicken sera, utilising a streptavidin-biotin detection protocol is described. this test was compared with a conventional elisa, which detects antibody using a peroxidase-labelled anti-turkey igg. the double-well streptavidin-biotin elisa was more sensitive than the conventional elisa, and, due to the consistently low background values obtained, was further modified to a sin ... | 1989 | 2555377 |
| observations on swollen head syndrome in broiler and broiler breeder chickens. | chickens on 14 broiler breeder farms were examined at various times throughout their laying cycle. antibodies to the turkey rhinotracheitis virus were common although they were not always accompanied by clinical signs of the swollen head syndrome. ninety-nine broiler flocks were tested of which only 20 were serologically positive to the virus. some of these infections were subclinical. on nine farms where swollen head syndrome occurred several successive flocks were sampled; the syndrome occurre ... | 1989 | 2800291 |
| experimental infection of turkeys, chickens, ducks, geese, guinea fowl, pheasants and pigeons with turkey rhinotracheitis virus. | | 1988 | 2842928 |
| isolation of turkey rhinotracheitis virus from five-day-old turkeys. | | 1988 | 3132782 |
| pneumovirus-like characteristics of the mrna and proteins of turkey rhinotracheitis virus. | electronmicroscopy has indicated that turkey rhinotracheitis virus (trtv), the causative agent of an acute respiratory disease in turkeys, is a member of the paramyxoviridae family. to determine if trtv belongs to one of the three defined genera of this family (paramyxovirus, morbillivirus and pneumovirus) we have analysed the rna and proteins induced during replication of trtv in vero cells. following replication in the presence of actinomycin d 10 polyadenylated rna bands, ranging in mr from 0 ... | 1988 | 3195218 |
| turkey rhinotracheitis virus: in vivo and in vitro polypeptide synthesis. | turkey rhinotracheitis (trt) virus is a paramyxovirus associated with recent outbreaks of acute respiratory disease in turkeys. on morphological criteria it resembles the pneumoviruses more than the other members of the paramyxovirus family. in this communication we report the identification of five virus-induced polypeptides in trt virus-infected bs-c-1 cells. the mr of these polypeptides were estimated as 38k, 35k, 30k, 19k and 15k from their electrophoretic mobility in sds-polyacrylamide 6 to ... | 1988 | 3356982 |
| protection provided by a commercially available vaccine against different strains of turkey rhinotracheitis virus. | | 1995 | 7604520 |
| a serosurvey using enzyme-linked immunosorbent assay for antibodies against poultry pathogens in ostriches (struthio camelus) from zimbabwe. | horseradish peroxidase-conjugated goat anti-ostrich igg was raised and used in commercial enzyme-linked immunosorbent assay kits to detect antibodies reactive with 11 poultry pathogens in sera from 149 ostriches from nine farms around zimbabwe. antibodies were detected to turkey rhinotracheitis virus (99%), newcastle disease virus (23%), avian reovirus (19%), infectious bursal disease virus (15%), avian encephalomyelitis virus (15%), mycoplasma gallisepticum and/or m. synoviae (11%), reticuloend ... | 1994 | 7832718 |
| protection against turkey rhinotracheitis pneumovirus (trtv) induced by a fowlpox virus recombinant expressing the trtv fusion glycoprotein (f). | a recombinant fowlpox virus was produced which expressed the fusion protein (f) of turkey rhinotracheitis virus (trtv), a pneumovirus. turkey poults were vaccinated twice, at an interval of 2 weeks, intramuscularly and by wing web on each occasion, with the recombinant or a control fowlpox virus. two weeks after the second vaccination the poults were challenged superconjunctivally and intranasally with virulent trtv. a partially protective immune response was achieved; turkeys vaccinated with th ... | 1994 | 8036832 |
| swollen head syndrome is not associated with turkey rhinotracheitis virus. | | 1993 | 8442337 |
| evaluation of different turkey rhinotracheitis viruses used as antigens for serological testing following live vaccination and challenge. | two enzyme-linked immunosorbent assays (elisa) developed in the authors' laboratory for turkey rhinotracheitis serological testing, a commercial elisa kit, and two virus-neutralization (vn) assays were compared with respect to the efficiency of these assays for serological monitoring in specific-pathogen-free (spf) turkeys inoculated with four pathogenic isolates of turkey rhinotracheitis virus, with or without previous live vaccination. both the live vaccine and the different isolates of virus ... | 1995 | 8553711 |
| 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 |
| a sequential histopathologic and immunocytochemical study of chickens, turkey poults, and broiler breeders experimentally infected with turkey rhinotracheitis virus. | the histopathologic changes and the distribution of turkey rhinotracheitis virus (trtv) antigen in the respiratory and reproductive tracts of experimentally infected chickens, turkey poults, and broiler breeders is described. trtv antigen was detected using both immunofluorescent staining of cryostat sections and immunoperoxidase staining of formalin-fixed tissues. viral antigen was observed associated with the cilia of the epithelial cells of turbinates, trachea, and lung. no trtv antigen and n ... | 1995 | 8719225 |
| detection of turkey rhinotracheitis virus from chickens with swollen head syndrome by reverse transcriptase-polymerase chain reaction (rt-pcr). | we developed a sensitive and specific method, reverse transcriptase-polymerase chain reaction (rt-pcr) method, for detection of turkey rhinotracheitis virus (trtv). two sets of primers were designed from f protein gene sequence of trtv 3b strain. sensitivity of detection by nested pcr with the primers corresponded to 0.4 tcid50. applying this method to a field case of swollen head syndrome (shs), trtv could be detected directly from chicken trachea and turbinates. it was identified that this met ... | 1996 | 8741270 |
| inhibition of cell fusion by neutralizing monoclonal antibodies to f1 protein of turkey rhinotracheitis virus. | two monoclonal antibodies (mabs) with neutralizing activities directed to the fusion (f) 1 glycoprotein of the 8597/cv94 strain of turkey rhinotracheitis (trt) virus inhibited cell fusion by trt virus in vitro. in contrast, f1-specific mabs with no neutralizing activity did not inhibit the cell fusion participating in syncytium formation. these findings indicate that the neutralization epitope is the same as or overlaps the fusion active site. | 1996 | 8811632 |
| a serological survey of turkey rhinotracheitis virus infection in chickens in japan. | a total of 4,111 chicken sera collected from 1985 to 1995 at 137 farms in 36 prefectures were subjected to an enzyme-linked immunosorbent assay (elisa) to test for antibodies against turkey rhinotracheitis (trt) virus. the antibodies to trt virus were detected in the chicken sera collected from 1988 to 1995, but the antibodies to trt virus were undetectable in the sera of chickens collected before 1987. the antibody positive rates each year ranged from 2.2% (1988) to 54.2% (1995). recently, the ... | 1996 | 8844610 |
| demonstration of serum-neutralising antibody to turkey rhinotracheitis virus in serum from chicken flocks in japan. | since between 1989 and 1991, broiler, broiler breeder and layer chickens reared in three different prefectures of japan, hyogo, ibaraki, and miyazaki, were diagnosed clinically as having swollen head syndrome (shs) these flocks were survey for antibody to turkey rhinotracheitis (trt) virus using a serum neutralisation (sn) test. trt-specific sn antibody was found in flocks of chickens in 2 out of the 3 prefectures. thereafter, particular in the summers of both 1993 and 1994 outbreaks of shs occu ... | 1996 | 8898285 |
| ultrastructural study of turkey rhinotracheitis virus infection in turbinates of experimentally infected chickens. | ultrastructural changes associated with turkey rhinotracheitis virus infection were studied in turbinates of chickens experimentally infected with the isolate cvl 14/86/1. chickens were sacrificed at 3, 5 and 7 days after inoculation and samples of the middle turbinate were taken, fixed, dehydrated and embedded in an hydrophilic resin. an immunofluorescence technique on semithin sections was carried out and viral antigen was observed in the cytoplasm and associated to cilia of the turbinate epit ... | 1996 | 8914249 |
| experimental infection in turkeys and chickens with ornithobacterium rhinotracheale. | ornithobacterium rhinotracheale was found to cause growth retardation in both turkeys and chickens after experimental intra-air sac administration and to cause growth retardation together with airsacculitis and pneumonia after aerosol administration. both turkey and chicken isolates of o. rhinotracheale were able to induce the same kind of respiratory inflammations and weight-gain losses in chickens as well as turkeys. turkey rhinotracheitis virus was found to have a triggering effect on the o. ... | 1996 | 8980818 |
| turkey rhinotracheitis virus and escherichia coli experimental infection in chickens: histopathological, immunocytochemical and microbiological study. | the aim of this study was to evaluate the response of chickens to a combined infection with turkey rhinotracheitis virus (trtv) and escherichia coli o78:k80. groups of specific-pathogen-free chickens were inoculated by eyedrop and intranasal routes with trtv and/or e. coli o78:k80. presence of e. coli o78:k80, histopathological changes and tissue distribution of viral antigen in the respiratory tract of chickens were evaluated. dual infection resulted in increased severity of clinical signs, and ... | 1997 | 9231979 |
| 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 |
| antigenic differentiation of turkey rhinotracheitis virus strains using monoclonal antibodies and polyclonal antisera. | monoclonal antibodies (mabs) were prepared against the 8597/cv94 strain of turkey rhinotracheitis virus (trtv). these mabs were used to investigate antigenic relationships among three strains (8597/cv94, 1162/92 and cvl14/1 strain) of trtv, together with polyclonal chicken and rabbit antisera to 8597/cv94 strain, and guinea pig antisera to each of the three strains. thirty mabs to the glycoprotein (g:3 clones), fusion (f1:6 clones), phosphorylated (p:6 clones), nucleocapsid (n:12 clones), and ma ... | 1997 | 9342704 |
| failure of maternal antibodies to protect young turkey poults against challenge with turkey rhinotracheitis virus. | groups of turkey poults with high levels of maternal antibodies (ma+) to turkey rhinotracheitis virus (trtv) were challenged with virulent trtv at 1, 5, and 10 days of age. a maternal antibody-free group (ma-) was also challenged at 1 day of age. before each challenge, levels of maternal antibodies to trtv were measured by enzyme-linked immunosorbent assay. clinical signs were scored for each group. unchallenged poults showed no signs. respiratory signs in poults infected at 10 days of age resem ... | 1997 | 9454934 |
| serological evidence for pneumovirus infections in pigs. | a serological survey was carried out on pig sera from herds in northern ireland to investigate the incidence of reactivity to bovine respiratory syncytial virus (brsv) antigens. a total of 529 pig sera from 61 herds were tested and 219 (41 per cent) were found to be reactive with brsv-infected cell cultures in an indirect immunofluorescence test. none of the brsv-reactive sera immunostained turkey rhinotracheitis virus-infected cell cultures, indicating specificity for brsv epitopes. the specifi ... | 1998 | 9460216 |
| 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 |
| comparison of f-, g- and n-based rt-pcr protocols with conventional virological procedures for the detection and typing of turkey rhinotracheitis virus. | fifty-six reverse transcriptions followed by a polymerase chain reaction (rt-pcr) were developed and/or assessed to detect and to type turkey rhinotracheitis virus (trtv). twenty-seven primers corresponding to sequences either common to both a and b viruses, or type-specific were respectively defined in the fusion (f), attachment (g) and nucleocapsid (n) proteins genes. only one n-based rt-pcr detected 21/21 trtvs isolated in four countries since 1985. molecular typing (rt-pcr) and antigenic typ ... | 1999 | 10446646 |
| 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 |
| occurrence of conjunctivitis, sinusitis and upper region tracheitis in japanese quail (coturnix coturnix japonica), possibly caused by mycoplasma gallisepticum accompanied by cryptosporidium sp. infection. | on a farm raising approximately 75,000 japanese quail (coturnix coturnix japonica) for egg production, the diseased quail showed clinical signs of swelling of the head, nasal discharge, increased lacrimation, and decreased egg production. the flock experienced a mortality rate of 5.7% per day. macroscopic observation revealed large, gelatinous masses of caseous exudate in the sinuses, egg peritonitis, and airsacculitis. microscopically, non-purulent or purulent inflammation accompanied by lympho ... | 2002 | 12396337 |
| 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 |
| 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 |
| 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 |
| avian and human metapneumovirus. | pneumovirus infection remains a significant problem for both human and veterinary medicine. both avian pneumovirus (ampv, turkey rhinotracheitis virus) and human metapneumovirus (hmpv) are pathogens of birds and humans, which are associated with 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, ampv and hmpv have been classified into a new genus referred to as me ... | 2007 | 17470912 |
| attempts to reproduce swollen head syndrome in specific pathogen-free chickens by inoculating with escherichia coli and/or turkey rhinotracheitis virus. | attempts to reproduce swollen head syndrome (shs) lesions were carried out in specific pathogen-free (spf) chickens. in experiment 1, chickens inoculated into the submucosal tissue of the nasal membrane or subcutaneous tissue of eyelids with four different strains of escherichia coli, developed typical shs lesions; purulent and necrotic lesions of facial subcutis (especially around their eyelids), periocular connective tissue, infraorbital sinus, air spaces, middle ears and eyeballs. the lesions ... | 1998 | 18483961 |
| pathogenicity of in vivo-passaged mycoplasma imitans in turkey poults in single infection and in dual infection with rhinotracheitis virus. | mycoplasma imitans (mim) is a close relative of mycoplasma gallisepticum (mg), but has been isolated from ducks, geese and partridge. in order to investigate its potential pathogenicity for turkeys a uk isolate of mim from a partridge with sinusitis was first passaged through turkey poults and then assessed for pathogenicity in turkey embryo tracheal organ cultures (tocs) and in one-day-old turkey poults with or without turkey rhinotracheitis virus (trtv). mim appeared to gain virulence on passa ... | 1998 | 18483968 |
| comparison of three commercial elisa kits for the detection of turkey rhinotracheitis virus antibodies. | three commercial elisas (pathasure, svanovir and flockscreen) were compared in their ability to detect turkey rhinotracheitis virus (trtv) vaccine-induced antibodies. sequential sera taken from specified pathogen-free chickens, vaccinated with two combinations of live and inactivated trtv vaccines were used. the vaccines were based on trtv strains from the united kingdom (intervet) and from france (rhone merieux). one elisa failed to detect antibodies after live vaccination with both french and ... | 1998 | 18484002 |
| the use of virus isolation, histopathology and immunoperoxidase techniques to study the dissemination of a chicken isolate of avian pneumovirus in chickens. | a subgroup b isolate of turkey rhinotracheitis virus (trtv) or avian pneumovirus (apv), obtained from a flock of commercial breeding chickens experiencing poor egg production, mortality and swollen head syndrome, was shown to cause substantial respiratory signs in both young spf chickens and chicks with high levels of maternally derived trt antibodies. this isolate replicated to high titre in the respiratory tract of experimentally inoculated spf chickens for approximately 5 days after inoculati ... | 1998 | 18484053 |
| an experimental turkey rhinotracheitis (trt) infection in breeding turkeys and the prevention of its clinical effects using live-attenuated and inactivated trt vaccines. | the experimental inoculation of 38-week-old turkey hens with a pool of field isolates of turkey rhinotracheitis virus (trtv) induced a marked respiratory infection and a substantial drop in egg production. administration of a live-attenuated trt vaccine at 1 week of age did not protect the layers against respiratory infection, but provided good protection against the effects of challenge on laying performance. however, a combination of live priming followed by injection of inactivated vaccine pr ... | 1996 | 18645855 |
| exacerbation of mycoplasma gallisepticum infection in turkeys by rhinotracheitis virus. | groups of 1-day-old turkey poults from a parent flock free of antibodies to turkey rhinotracheitis virus (trtv) and the pathogenic mycoplasmas, were infected by eyedrop with virulent trtv, with mycoplasma gallisepticum (mg) or with both agents together. dual infection resulted in increased morbidity compared with those groups given single infections. the presence of the mg in the dual infection had no apparent effect on the pathogenesis of the virus, but the virus caused the mycoplasma to be mor ... | 1992 | 18670941 |
| in vitro and in vivo studies in chickens and turkeys on strains of turkey rhinotracheitis virus isolated from the two species. | some biological properties of two strains of turkey rhinotracheitis virus, isolated 10 years apart in south africa, one from turkeys and one from chickens, have been compared. whilst in vitro cross-neutralization tests showed them to be closely related antigenically they showed different in vivo properties. both strains elicited an antibody response and caused clinical signs of infection in both chickens and turkeys although the signs tended to be more marked in the species from which the trtv h ... | 1993 | 18671004 |
| antigenic differentiation of strains of turkey rhinotracheitis virus using monoclonal antibodies. | monoclonal antibodies (mabs) were prepared against one uk isolate of turkey rhinotracheitis virus (trtv). those which were virus-neutralizing were selected and used, together with polyclonal antisera raised to each isolate in turkeys, in cross-neutralization tests against trtv strains isolated in the uk and elsewhere. whilst the polyclonal antisera showed that there was some diversity between them, all strains examined belonged to one serotype. the trtv strains isolated in the uk could clearly b ... | 1993 | 18671016 |
| detection of turkey rhinotracheitis virus in turkeys using the polymerase chain reaction. | six-week-old turkey poults were infected with the virulent uk/3b/85 strain of trtv. tracheal and oesophageal swabs were made every 2 to 3 days from groups of five poults and the rna extracted. the trtv rna was then reverse-transcribed into complementary dna (cdna) using an oligonucleotide complementary to the 3' end of the fusion protein (f) mrna. the cdna was then used in a polymerase chain reaction (pcr) with an upstream primer to generate a product of approximately 0.5 kbp which was detected ... | 1993 | 18671060 |
| swollen head syndrome in taiwan-isolation of an avian pneumovirus and serological survey. | outbreaks of swollen head syndrome (shs) were observed in two broiler and two broiler-breeder farms in taiwan. the disease was characterized by oedematous swelling of the head, especially surrounding the eyelids, the neck and wattles. avian pneumovirus and escherichia coli were isolated from birds in all four farms. in addition, staphylococcus aureus and infectious bursal disease virus were each isolated from one farm. a serological survey of 398 birds from 11 broiler breeder farms showed 86.4% ... | 1994 | 18671082 |
| a comparison of three methods for detecting antibodies to turkey rhinotracheitis virus. | sera from a flock of naturally infected commercial turkeys were tested for antibodies against turkey rhinotracheitis virus using an indirect immunofluorescence test with infected turkey embryo tracheal organ cultures, a serum neutralisation test using chick embryo fibro-blasts or liver cells and an elisa. antibodies were detected by all tests within 5 days of the appearance of clinical respiratory disease. serum neutralising antibodies detected in chick embryo fibroblasts rapidly achieved their ... | 1989 | 18679840 |
| a live attenuated turkey rhinotracheitis virus vaccine. 1. stability of the attenuated strain. | compared with the severe clinical disease caused by two virulent strains of turkey rhinotracheitis virus (trtv), an attenuated strain has been shown to cause only slight respiratory infection in 7-day-old trt-free turkey poults, yet still to be capable of stimulating trt antibodies and of protecting the poults against challenge with virulent trtv 21 days later. the stability of the attenuation during 12 turkey-turkey passages of the strain has been demonstrated; the poult passaged and prepassage ... | 1989 | 18679881 |
| a live attenuated turkey rhinotracheitis virus vaccine. 2. the use of the attenuated strain as an experimental vaccine. | an attenuated turkey rhinotracheitis (trt) vaccine strain, when given either by eye drop or by aerosol, has been shown to be effective in protecting 1- to 11-day-old turkey poults against an experimental challenge with trtv up to 14 weeks later. trt antibody-free poults and poults hatched from trt-immune dams were both equally well protected, although a high proportion of the latter did not respond serologically to the vaccine. as little as 1 cd50 of vaccine was found to be effective in protecti ... | 1989 | 18679882 |
| attenuation of turkey rhinotracheitis virus by alternative passage in embryonated chicken eggs and tracheal organ cultures. | turkey rhinotracheitis virus (trtv) was still infective for turkey poults after 30 cycles of alternate passages in 9-day-old chicken embryos and tracheal organ cultures. it caused only mild, transient respiratory signs yet protected against challenge with virulent trtv 21 days later. it is suggested that this attenuated strain has potential for use as a vaccine. | 1990 | 18679926 |
| the detection of turkey rhinotracheitis virus antigen in formalin fixed, paraffin embedded tissue using a streptavidin-biotin-immunoperoxidase method. | the detection of turkey rhinotracheitis (trt) virus antigen in both formalin-and bouin's-fixed paraffin embedded tissue using a streptavidin-biotin immunoperoxidase staining technique is described. trt antigen was detected in bouin's-fixed tissue without prior treatment with proteolytic enzymes. however, demonstration of trt antigen in formalin-fixed tissue was only achieved after pretreatment with protease xiv. viral antigen was seen in the ciliated epithelial cells of trachea and turbinates fr ... | 1990 | 18679948 |
| the pathogenesis of turkey rhinotracheitis virus in turkey poults inoculated with the virus alone or together with two strains of bacteria. | turkey rhinotracheitis virus (trtv) was recovered in large amounts from the upper respiratory tract of young turkey poults for about 5 days after experimental eyedrop inoculation with either a virulent or an attenuated strain. thereafter, small amounts of virus were isolated, but only for up to 14 days after inoculation. virulent trtv could be recovered infrequently from the internal organs or the intestinal tract but only if bacteria (bordetella avium and a pasteurella-like organism) were admin ... | 1991 | 18680008 |
| demonstration of antibodies to turkey rhinotracheitis virus in serum from commercially reared flocks of chickens. | using both an elisa and a serum neutralisation test, antibodies to turkey rhinotracheitis (trt) virus were found in sera collected from commercial flocks of chickens after the initial appearance of trt in turkeys in britain in mid-1985 but not in chicken sera collected before that time. good correlation was found between the results of the two assays and antibodies were found in chickens of all commercial types and of all ages, ranging from 31 days to 56 weeks. apparently healthy flocks appeared ... | 1988 | 18766697 |
| experimental infection of laying turkeys with rhinotracheitis virus: distribution of virus in the tissues and serological response. | twenty-four laying turkey hens shown to be free of antibodies to turkey rhinotracheitis virus were inoculated intranasally with an isolate of the virus. a mild respiratory disease developed between 5 and 9 days post infection (pi). two birds were selected at random at intervals between days 1 and 20 pi, killed and tissues examined for the presence of virus. at autopsy between days 2 and 12 abnormalities were found in the oviducts including the deposition of inspissated albumen. yolk material was ... | 1988 | 18766745 |
| innovation and discovery: the application of nucleic acid-based technology to avian virus detection and characterization. | polymerase chain reaction (pcr)-based approaches to the detection, differentiation and characterization of avian pathogens continue to be developed and refined. the pcrs, or reverse transcriptase-pcrs, may be general, designed to detect all or most variants of a pathogen, or to be serotype, genotype or pathotype specific. progress is being made with respect to making nucleic acid approaches more suitable for use in diagnostic laboratories. robotic workstations are now available for extraction of ... | 2001 | 19184952 |
| development, standardization and assessment of pcr systems for purity testing of avian viral vaccines. | the european pharmacopoeia (ph. eur.) requires avian viral vaccines to be free of adventitious agents. purity testing is an essential quality requirement of immunological veterinary medicinal products (ivmps) and testing for extraneous agents includes monitoring for many different viruses. conventional virus detection methods include serology or virus culture, however, molecular tests have become a valid alternative testing method. nucleic acid testing (nat) is fast, highly sensitive and has a h ... | 2010 | 20338785 |
| methyltransferase-defective avian metapneumovirus vaccines provide complete protection against challenge with the homologous colorado strain and the heterologous minnesota strain. | avian metapneumovirus (ampv), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. since its discovery in the 1970s, ampv has been recognized as an economically important pathogen in the poultry industry worldwide. the conserved region vi (cr vi) of the large (l) polymerase proteins of paramyxoviruses catalyzes methyltransferase (mtase) activities that typically methylate viral ... | 2014 | 25122790 |
| a reverse genetics approach for the design of methyltransferase-defective live attenuated avian metapneumovirus vaccines. | avian metapneumovirus (ampv), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. ampv belongs to the family paramyxoviridae which includes many important human pathogens such as human respiratory syncytial virus (rsv), human metapneumovirus (hmpv), and human parainfluenza virus type 3 (piv3). the family also includes highly lethal emerging pathogens such as nipah virus and hen ... | 2016 | 27076293 |
| prevalence of avian metapneumovirus subtype b in live bird market in gilan province, iran. | avian metapneumovirus (ampv), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and swollen head syndrome in chickens. four ampv subgroups (a-d) have been reported previously based on their genetic and antigenic differences. evidence suggests that the live bird markets (lbms) play an important role in the epidemiology of the avian viral diseases. a total number of 450 oropharyngeal samples from eight different species of birds (migr ... | 2018 | 29719670 |