Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
use of defective rnas containing reporter genes to investigate targeted recombination for avian infectious bronchitis virus. 200111774516
functional ibv minigenomes generated by recombinant fowl pox viruses for use in ibv-targeted recombination studies. 200111774520
sequences required for replication and packaging of ibv rna. 200111774523
characterization of temperature-sensitive (ts) mutants of coronavirus infectious bronchitis virus (ibv). 200111774524
infectious bronchitis virus envelope protein targeting: implications for virus assembly. 200111774527
physical interaction between the membrane (m) and envelope (e) proteins of the coronavirus avian infectious bronchitis virus (ibv). 200111774531
infectious bronchitis virus nucleocapsid protein interactions with the 3' untranslated region of genomic rna depend on uridylate bases. 200111774543
isolation and characterization of a novel antigenic subtype of infectious bronchitis virus serotype de072.three infectious bronchitis virus (ibv) isolates, cu82792, cu82805, and cu82808, were recovered from sentinel chickens placed with three different layer flocks of a large commercial poultry farm in new york state. the three isolates were classified as members of the de072 serotype on the basis of 1) their s1 genes could be amplified with only a modified primer designed for the de072 serotype and 2) their restriction fragment length polymorphism patterns, after digestion with endonucleases haeiii ...200111785878
novel infectious bronchitis virus s1 genotypes in mexico 1998-1999.seventeen infectious bronchitis virus (ibv) field isolates recovered from commercial broiler flocks in mexico were identified by reverse transcription-polymerase chain reaction cycle sequencing of the s1 gene. the isolates were obtained from broilers on farms from the neighboring states of queretaro and san luis potosi in 1998 and 1999. flocks had an ongoing history of bacterial-complicated respiratory disease with mortality rates as high as 28% in spite of receiving live vaccinations for massac ...200111785879
antigenic and genomic relatedness of turkey-origin coronaviruses, bovine coronaviruses, and infectious bronchitis virus of chickens.in earlier studies in our laboratory, we found that bovine coronavirus (bcv) was pathogenic for 1-day-old turkey poults. this finding prompted us to study the antigenic and genomic relatedness of turkey origin coronaviruses (tocvs) to bcv. a one-step reverse transcription (rt)-polymerase chain reaction (pcr) targeting a 730-base pair fragment of the nucleocapsid (n) gene of bcv and a nested pcr targeting a 407-base pair fragment of the n gene were used in an attempt to detect tocv from north car ...200111785902
chicken interferon type i inhibits infectious bronchitis virus replication and associated respiratory illness.infectious bronchitis virus (ibv) causes an economically important respiratory disease in poultry worldwide. previous studies have shown that cd8(+) cytotoxic t lymphocytes (ctl) are critical in controlling acute ibv infection, but the role of innate immunity is unknown. this study describes the in vitro and in vivo anti-ibv activity of natural spleen cell-derived and recombinant chicken interferon type i (rchifn-alpha). both natural and rchifn-alpha inhibited replication of the beaudette strain ...200111798465
further identification and characterization of products processed from the coronavirus avian infectious bronchitis virus (ibv) 1a polyprotein by the 3c-like proteinase. 200111774483
detection of a coronavirus from turkey poults in europe genetically related to infectious bronchitis virus of chickens.intestinal contents of 13-day-old turkey poults in great britain were analysed as the birds showed stunting, unevenness and lameness, with 4% mortality. at post mortem examination, the main gross features were fluid caecal and intestinal contents. histological examination of tissues was largely unremarkable, apart from some sections that showed crypt dilation and flattened epithelia. negative contrast electron microscopy of caecal contents revealed virus particles, which in size and morphology h ...200119184921
epidemiology of infectious bronchitis virus in belgian broilers: a retrospective study, 1986 to 1995.infectious bronchitis virus (ibv) was isolated from each of 236 broiler flocks that had respiratory infection (86%), impaired growth, enteritis and/or nephritis (14%), over a 10-year period from 1986 to 1995 in belgium. among them, 65% of the investigated flocks had not been vaccinated against infectious bronchitis. type-specific reverse transcriptase polymerase chain reactions (rt-pcrs) were used after propagation of the isolates in embryonated eggs in order to detect and differentiate massachu ...200119184926
protection of chickens against renal damage caused by a nephropathogenic infectious bronchitis virus.the ability of the infectious bronchitis (ib) ma5 and 4/91 live-attenuated vaccines to protect against kidney damage caused by a nephropathogenic strain of ib virus (b1648) was investigated. protection parameters considered were gross and microscopic renal pathology, and the use of a polymerase chain reaction to detect ib rna in kidney tissue. by each parameter, ma5 vaccine alone provided poor protection, but 4/91 alone or the combined program both protected well.200119184927
safety and efficacy of water-in-oil-in-water emulsion vaccines containing newcastle disease virus haemagglutinin-neuraminidase glycoprotein.subunit vaccines containing haemagglutinin-neuraminidase (hn) glycoprotein of newcastle disease virus (ndv), formulated as water-in-oil-in-water (w/o/w) emulsions, were prepared. first, the suitable constituents of a w/o/w emulsion adjuvant were investigated with polyvalent vaccines using ndv, infectious bronchitis virus and haemophilus paragallinarum. the w/o/w emulsion adjuvant, composed of the antigen in phosphate-buffered saline (pbs), liquid paraffin, squalene, diglyceryl monooleate, polyso ...200119184940
sequence analysis of nephropathogenic infectious bronchitis virus strains of the massachusetts genotype in beijing.the first 440 nucleotides of the s1 part of the spike protein (s) gene of three nephropathogenic infection bronchitis virus (ibv) strains (bj1, bj2 and bj3), isolated from three rural chicken farms of beijing with outbreaks of avian infectious bronchitis, were sequenced after reverse transcriptasenested polymerase chain reaction amplification. the sequence data were analyzed and compared with the standard ibv strains m41, beaudette, vaccine strain h120 and chinese vaccine strain d41. the three i ...200119184943
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 ...200119184952
a nomenclature for avian coronavirus isolates and the question of species status.currently, there is no agreed naming system for isolates of infectious bronchitis virus (ibv), whose host is the domestic fowl (gallus gallus domesticus). a uniform, informative system for naming ibv isolates would be very helpful. furthermore, the desirability of a single naming system has become more important with the recent discoveries that coronaviruses with genome organizations and gene sequences very similar to those of ibv have been isolated from turkeys (meleagris gallopavo) and pheasan ...200119184884
infectious bronchitis virus vaccine interferes with the replication of avian pneumovirus vaccine in domestic fowl.experiments were performed in chickens to ascertain whether application of infectious bronchitis (ib) h120 vaccine had an effect on the replication of an attenuated avian pneumovirus (apv) strain, using as indicators virus detection, humoral antibody responses and clinical protection against in vivo apv challenge. a preliminary experiment demonstrated that pharyngeal swabs were as efficient for recovery of apv as were buccal cavity swabs, and that either site was superior to swabbing the nasal c ...200119184905
antigenic relationship of turkey coronavirus isolates from different geographic locations in the united states.the purpose of the present study was to examine the antigenicity of turkey coronavirus (tcv) isolates from various geographic areas with antibodies to different viruses. seventeen isolates of tcv were recovered from intestinal samples submitted to animal disease diagnostic laboratory, purdue university, from turkey farms located in different geographic areas. the prototype tcv minnesota isolate (tcv-atcc) was obtained from the american type culture collection. intestinal sections were prepared f ...200212061660
dietary arginine intake alters avian leukocyte population distribution during infectious bronchitis challenge.although dietary arginine is a factor in immune function and disease resistance, the full range of effects has yet to be described. in this study, the effects of dietary arginine on leukocyte population changes were examined in the peripheral blood and the respiratory tract of chickens inoculated with infectious bronchitis virus (ibv) strain m41. at 2 wk of age, female line p2a white leghorn-type chickens were randomly assigned to one of three diets with different arginine levels: a marginally d ...200212079045
pulse and continuous oral norfloxacin treatment of experimentally induced escherichia coli infection in broiler chicks and turkey poults.experimental colibacillosis was produced in 40 healthy, 7-day-old broiler chickens and turkeys by intratracheal injection of 1 x 10(8) cfu/chick and 1.23 x 10(9) cfu/poult bacteria of an o1:f11 strain of escherichia coli, respectively. two days before e. coli challenge all chicks were vaccinated with a live attenuated strain of infectious bronchitis virus (h-52). this model of infection--at least in chicken--proved to be useful for evaluating the efficacy of antimicrobial medication, by recordin ...200212113175
molecular characterization of three new avian infectious bronchitis virus (ibv) strains isolated in quebec.three unrecognized field isolates of infectious bronchitis virus (ibv) were recovered from commercial broiler chickens vaccinated with live mass viral strain (h120). these isolates were identified by immunofluorescence using monoclonal antibodies produced against reference serotypes: mass, conn, and ark. rt-pcrs were performed on viral rnas to amplify s1 gene using a specific set of primers s1oligo3' and s1oligo5'. restriction polymorphism (rflp) of pcr products was determined by the use of haei ...200212206312
field trial in commercial broilers with a multivalent in ovo vaccine comprising a mixture of live viral vaccines against marek's disease, infectious bursal disease, newcastle disease, and fowl pox.a multivalent in ovo vaccine (miv) was tested for safety and efficacy in a commercial broiler complex. the miv comprised five replicating live viruses including serotypes 1, 2, and 3 of marek's disease virus (mdv), an intermediate infectious bursal disease virus (ibdv) and a recombinant fowl poxvirus (fpv) vector vaccine containing hn and f genes of newcastle disease virus (ndv). the performance of miv-vaccinated broilers was compared with that of hatchmates that received turkey herpesvirus (hvt ...200212243525
detection of in ovo-inoculated infectious bronchitis virus by immunohistochemistry and in situ hybridization with a riboprobe in epithelial cells of the lung and cloacal bursa.in situ hybridization and immunohistochemistry were utilized to identify tissues infected in ovo with infectious bronchitis virus (ibv). chicken embryos were inoculated in ovo (chorioallantoic sac) with the arkansas (ark) serotype of ibv at 18 days of age. at 24, 48, 72, and 120 hr postinfection (hpi), bursa, lung, spleen, heart, and thymus were collected, fixed in 10% neutral buffered formalin, and paraffin embedded. the digoxigenin-labeled antisense s1 riboprobe detected viral mrna in the cyto ...200212243532
development and application of a multiplex polymerase chain reaction for avian respiratory agents.a multiplex polymerase chain reaction (pcr) was developed and optimized to simultaneously detect 6 avian respiratory pathogens. six sets of specific oligonucleotide primers for infectious bronchitis virus (ibv), avian influenza virus (aiv), infectious laryngotracheitis virus (iltv), newcastle disease virus (ndv), mycoplasma gallisepticum (mg), and mycoplasma synoviae (ms) were used respectively in the test. with the use of agarose gel electrophoresis for detection of the pcr-amplified dna produc ...200212243534
tissue distribution of avian infectious bronchitis virus following in ovo inoculation of chicken embryos examined by in situ hybridization with antisense digoxigenin-labeled universal riboprobe.chicken embryos were inoculated with 8 different strains of infectious bronchitis virus (ibv) representing 7 different serotypes at 17 days of embryonation. at 2 and 5 days postinfection (dpi), tissues were collected for in situ hybridization using an antisense digoxigenin-labeled riboprobe corresponding to the sequence of the mrna coding for the membrane protein. extensive antigen staining in the cytoplasm of epithelial cells in the trachea, lung, bursa, and intestine was detected at 2 dpi with ...200212296388
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 ...200212371689
existence of gene 5 indicates close genomic relationship of turkey coronavirus to infectious bronchitis virus.a segment of genomic rna extending from the 3'-end of the membrane (m) protein gene to the 5'-end of the nucleocapsid (n) protein gene of turkey coronavirus (tcv) was amplified by reverse transcription-polymerase chain reaction (rt-pcr). the primers were derived from the corresponding sequences of infectious bronchitis virus (ibv). the pcr products were cloned and sequenced and their nucleic acid structure and similarity to the published sequences of ibv were analyzed. gene 5 containing two over ...200212387503
molecular epizootiology of infectious bronchitis virus in sweden indicating the involvement of a vaccine strain.to improve the detection and molecular identification of infectious bronchitis virus (avian coronavirus), two reverse transcriptase-polymerase chain reaction (pcr) assays were developed. as 'diagnostic#10; pcr', a set of consensus nested primers was selected from highly conserved stretches of the nucleocapsid (n) gene. as 'phylogeny' pcr, a fragment of the spike protein gene (s1) was amplified and the pcr products were directly sequenced. to study the phylogenetic relationships of the viruses fr ...200212396345
natural cases and an experimental study of h9n2 avian influenza in commercial broiler chickens of iran.since 1998, an epidemic of avian influenza has occurred in the iranian poultry industry. the agent was pathotyped as non-highly pathogenic and subtyped as an h9n2 avian influenza virus. therefore it did not require eradication. however, frequent incidences of high mortality were observed commonly on broiler farms. no other species of bird were affected. the circulation of the virus and mixed infection with other respiratory pathogens, particularly infectious bronchitis virus and mycoplasma galli ...200212396348
the role of feline aminopeptidase n as a receptor for infectious bronchitis virus. brief review.feline aminopeptidase n (fapn) has been shown to serve as a receptor for feline, canine, porcine and human coronaviruses. our objective was to determine if fapn can serve as a receptor for infectious bronchitis virus (ibv). feline kidney cells that express fapn and hamster kidney fibroblasts that do not express fapn were inoculated with ibv and monitored for replication by indirect fluorescent assay and confocal microscopy and in chicken embryonated eggs. the results showed that the feline cells ...200212417943
conservation of substrate specificities among coronavirus main proteases.the key enzyme in coronavirus replicase polyprotein processing is the coronavirus main protease, 3cl(pro). the substrate specificities of five coronavirus main proteases, including the prototypic enzymes from the coronavirus groups i, ii and iii, were characterized. recombinant main proteases of human coronavirus (hcov), transmissible gastroenteritis virus (tgev), feline infectious peritonitis virus, avian infectious bronchitis virus and mouse hepatitis virus (mhv) were tested in peptide-based t ...200211842254
an elisa for antibodies against infectious bronchitis virus using an s1 spike polypeptide.using the whole infectious bronchitis virus (ibv) for detecting the antibody against ibv by enzyme-linked immunosorbent assay (elisa) is a routine work in poultry industry. to prepare virus is time consuming and tedious. furthermore, the whole viral antigen detects all antibodies against the viral structural proteins, including spike (s), nucleocapsid, matrix, and other proteins. among those, s protein is related to neutralization. thus, to develop and express protein fragment from s gene and to ...200211856583
antibody responses and morbidity following infection with infectious bronchitis virus and challenge with escherichia coli, in lines divergently selected on antibody response.we evaluated the association between antibody (ab) production and disease resistance. a controlled-challenge protocol was developed to mimic natural infection and to yield a higher rate of mortality following escherichia coli (ec) challenge. chicks were first infected with infectious bronchitis virus (ibv) by injecting a high dose of vaccine (attenuated virus) into their air sacs and then were infected with pathogenic ec introduced intratracheally. the experimental population consisted of lines ...200211873823
embryonic exposure to lead: comparison of immune and cellular responses in unchallenged and virally stressed chickens.lead, a ubiquitous environmental contaminant, has been shown to modulate various functions of the immune system and decrease host resistance to infectious disease. however, limited information is available concerning the direct effects of lead on the host immune response to an infectious agent after developmental exposure. the current study utilized chickens to examine the effect of embryonic lead exposure on immune and cellular responses during viral challenge. sublethal doses of lead were intr ...200211876505
pathogenicity of australian strains of avian infectious bronchitis virus.the pathogenicity of 25 strains of infectious bronchitis virus (ibv) isolated in australia between 1961 and 1994 was compared in white leghorn specific pathogen-free chicks. twelve strains were nephropathogenic and 10 respiratory, the other three being of mixed pathogenicity. the ibv strains identified as nephropathogenic induced clinical nephritis, gross and histological kidney lesions, and mortality of 5-90%. according to the severity of these features, the nephropathogenic strains could be fu ...200211945000
interaction of the coronavirus nucleoprotein with nucleolar antigens and the host cell.coronavirus nucleoproteins (n proteins) localize to the cytoplasm and the nucleolus, a subnuclear structure, in both virus-infected primary cells and in cells transfected with plasmids that express n protein. the nucleolus is the site of ribosome biogenesis and sequesters cell cycle regulatory complexes. two of the major components of the nucleolus are fibrillarin and nucleolin. these proteins are involved in nucleolar assembly and ribosome biogenesis and act as chaperones for the import of prot ...200211967337
membrane association and dimerization of a cysteine-rich, 16-kilodalton polypeptide released from the c-terminal region of the coronavirus infectious bronchitis virus 1a polyprotein.more than 10 mature proteins processed from coronavirus gene 1-encoded polyproteins have been identified in virus-infected cells. here, we report the identification of the most c-terminal cleavage product of the 1a polyprotein as a 16-kda protein in infectious bronchitis virus-infected vero cells. indirect immunofluorescence demonstrated that the protein exhibits a distinct perinuclear punctate staining pattern, suggesting that it is associated with cellular membranes. positive staining observed ...200212021359
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 ...200212054135
development of a competitive enzyme-linked immunosorbent assay for detection of turkey coronavirus antibodies.a competitive enzyme-linked immunosorbent assay (celisa) was developed for detection of turkey coronavirus (tcv) antibodies. the celisa utilized a recombinant baculovirus (autographa californica nuclear polyhedrosis virus)-expressed tcv nucleocapsid (n) protein and biotin-labeled tcv n protein-specific monoclonal antibody. sensitivity and specificity of the celisa for detection of tcv antibodies were determined by comparison with the indirect fluorescent antibody test (ifat) with 1269 reference, ...200212061642
genetic and antigenic diversity in avian infectious bronchitis virus isolates of the 1940s.in order to verify a commonly held assumption that only massachusetts (mass) serotype of infectious bronchitis virus (ibv) was prevalent in the united states between the 1930s (when ibv was first isolated) and the 1950s (when the use of commercial ibv vaccines began), we examined 40 ibv field isolates from the 1940s. thirty-eight of those isolates were recognized as mass serotype viruses based on their reactivity to mass-specific monoclonal antibody (mab) and neutralization by mass-specific chic ...200212061655
construction and immunogenicity studies of recombinant fowl poxvirus containing the s1 gene of massachusetts 41 strain of infectious bronchitis virus.the spike 1 (s1) surface glycoprotein of infectious bronchitis virus (ibv) is the major inducer of the generation of virus neutralizing antibodies, and the administration of purified s1 has been shown to elicit a protective immune response against virulent virus challenge. on the basis of these observations, recombinant fowl poxvirus (rfpv) containing a cdna copy of the s1 gene of ibv mass 41 (rfpv-s1) was constructed and its immunogenicity and vaccine potential were evaluated. initially, rfpv-s ...200212495043
nephropathogenic infectious bronchitis in pennsylvania chickens 1997-2000.nephropathogenic infectious bronchitis (nib) was diagnosed in 28 infectious bronchitis virus (ibv)-vaccinated commercial chicken flocks in pennsylvania from december 1997 to july 2000. early dinical signs were increased flock mortality and urinary water loss (polyuria and pollakiuria) leading to wet litter. daily mortality ranged from 0.01% in layers to 2.45% in broilers, with total broiler mortality as high as 23%. severe renal swelling and accumulation of urates in the tubules were commonly se ...200212495045
coronaviruses from pheasants (phasianus colchicus) are genetically closely related to coronaviruses of domestic fowl (infectious bronchitis virus) and turkeys.reverse-transcriptase polymerase chain reactions (rt-pcrs) were used to examine rna extracted from mouth/nasal swabs from pheasants exhibiting signs of respiratory disease. the oligonucleotides used were based on sequences of infectious bronchitis virus (ibv), the coronavirus of domestic fowl. a rt-pcr for the highly conserved region ii of the 3' untranslated region of the ibv genome detected a coronavirus in swabs from 18/21 estates. sequence identity with the corresponding region of ibvs and c ...200212425795
gastric gross and microscopic lesions caused by the unam-97 variant strain of infectious bronchitis virus after the eighth passage in specific pathogen-free chicken embryos.herein we report a description of gross and microscopic lesions found in specific pathogen-free chicken embryos caused by unam-97 infectious bronchitis virus (ibv) variant strain after the eighth passage. embryos were divided into three groups and were inoculated in the chorioallantoic sac with 0.2 ml of unam-97, mass 41 ibv (positive control), or sterile pbs (negative control). forty-eight hours later the allatoic fluid was taken and used to start a cycle of eight passages through 9-d-old embry ...200212455591
protection of chickens after live and inactivated virus vaccination against challenge with nephropathogenic infectious bronchitis virus pa/wolgemuth/98.protection provided by live and inactivated virus vaccination against challenge with the virulent nephropathogenic infectious bronchitis virus (nibv) strain pa/wolgemuth/98 was assessed. vaccinations with combinations of live attenuated strains massachusetts (mass) + connecticut (conn) or mass + arkansas (ark) were given by eyedrop to 2-wk-old specific-pathogen-free leghorn chickens. after live infectious bronchitis virus (ibv) vaccination, some chickens at 6 wk of age received an injection of e ...200212495055
infectious disease survey of lesser prairie chickens in north texas.lesser prairie chicken (tympanuchus pallidicinctus) abundance, like that of most grassland birds, has declined rangewide for decades. although habitat loss and degradation are likely ultimate causes for this decline, infectious agents, particularly microparasites, could be proximate contributors. no surveys of pathogenic bacteria or viruses have been published for this species. we surveyed 24 free-living lesser prairie chickens from hemphill county, texas (usa), for evidence of exposure to salmo ...200212528454
epididymal lithiasis in roosters and efferent ductule and testicular damage.epididymal stones have been reported in roosters in the usa and japan. the cause of this dysfunction, which is associated with low fertility, is not known. the hypothesis of the present study is that a potential cause is the aggressive selection of birds over many centuries based upon female egg laying traits, without concern for potential effects on the male. if this hypothesis is correct, one potential consequence would be the presence of epididymal stones only in domesticated fowl and this ob ...200212530920
detection and estimation of avian infectious bronchitis virus antigen by a novel indirect liquid-phase blocking enzyme-linked immunosorbent assay using chicken and rabbit affinity purified immunoglobulins.an indirect liquid-phase blocking (lpb) enzyme-linked immunosorbent assay (elisa) using chicken and rabbit affinity purified immunoglobulin g (igg) has been developed to detect and estimate avian infectious bronchitis virus (ibv) antigen concentration directly in infected allantoic fluid. the method is based on the principle of binding of specific igg to the test ibv antigen and the assay of unbound igg on an antigen-coated elisa plate. the immunoglobulins are chicken n-terminal s2 peplomeric pr ...200212593737
the cytoplasmic tail of infectious bronchitis virus e protein directs golgi targeting.we have previously shown that the e protein of the coronavirus infectious bronchitis virus (ibv) is localized to the golgi complex when expressed exogenously from cdna. here, we report that neither the transmembrane domain nor the short lumenal domain of ibv e is required for golgi targeting. however, an n-terminal truncation containing only the cytoplasmic domain (cte) was efficiently localized to the golgi complex, and this domain could retain a reporter protein in the golgi. thus, the cytopla ...200211773403
changes in serum ovotransferrin levels in chickens with experimentally induced inflammation and diseases.a competitive enzyme immunoassay was developed to measure the changes in serum levels of ovotransferrin (otf) during inflammation and infectious diseases in chickens. the assay is based on the competition of serum otf with a fixed concentration of biotin-labeled otf to bind to a rabbit anti-chicken transferrin antibody immobilized on microtiter wells. after several washing steps, the antibody-bound biotinylated otf is probed with streptavidin-horseradish peroxidase conjugate (hrp) followed by a ...200211922323
serum levels of mannan-binding lectin in chickens prior to and during experimental infection with avian infectious bronchitis virus.mannan-binding lectin (mbl) is a glycoprotein and a member of the c-type lectin super family, the collectin family, and the acute phase protein family. the mbl exerts its function by directly binding to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonization or complement activation via mbl-associated serine proteases (masp)-1 and -2. thus, mbl plays a major role in the first-line innate defense against pathogens. we investigated the mbl concentrations in ...200312619800
susceptibility of three genetic lines of chicks to infection with a nephropathogenic t strain of avian infectious bronchitis virus.mortality rates were compared in three genetic lines of specific pathogen-free chicks inoculated with one of two doses of a nephropathogenic strain of avian infectious bronchitis (ib) virus. the mortality rates were influenced primarily by the chick strain, but also by age and dose of virus. chicks of the inbred s line were highly susceptible. after inoculation with a low dose of virus at 2 and 4 weeks of age, mortality was 90 and 45%, respectively. chicks of the hwl non-inbred line were also su ...200312634084
memory t cells protect chicks from acute infectious bronchitis virus infection.infectious bronchitis has remained one of the most difficult to control diseases in poultry since it was first described in 1931. previous studies demonstrated that primary cd8(+) t lymphocytes collected at 10 days post-infection (p.i.) are important in controlling acute infection. to further investigate the role of memory t cells in protection, t lymphocytes collected from b19/b19 chicken spleens at 2, 3, 4, and 6 weeks p.i. were transferred to six-day-old syngeneic chicks one day prior to chal ...200312642110
detection of infectious bronchitis virus by multiplex polymerase chain reaction and sequence analysis.a multiplex reverse transcription-polymerase chain reaction (rt-pcr) was developed to amplify the s1 and s2 genes of vaccine and recent taiwanese isolates of infectious bronchitis virus (ibv). dna fragments of 228 and 400 base pairs in length were amplified among ibv isolates in multiplex pcr, suggesting that there were no apparent deletions or insertions in these regions. no pcr products were amplified from unrelated avian viruses and negative controls. the results suggested that multiplex pcr ...200312668265
avian infectious bronchitis: characterization of new isolates from italy.the isolation of four new variants or serotypes of avian infectious bronchitis virus in italy is reported. the antigenic characteristics of these strains were investigated by cross-neutralization tests with the new isolates, fa 6881/97, az 27/98, az 20/97, and bs 216/01; two of the most common european serotypes, az 23/74 and cr 88121 (793b); and the classic massachusetts m41 serotype in association with a panel of 17 specific antisera. on the basis of the results obtained, the new isolates show ...200312713175
in vitro and in ovo expression of chicken gamma interferon by a defective rna of avian coronavirus infectious bronchitis virus.coronavirus defective rnas (d-rnas) have been used for site-directed mutagenesis of coronavirus genomes and for expression of heterologous genes. d-rna cd-61 derived from the avian coronavirus infectious bronchitis virus (ibv) was used as an rna vector for the expression of chicken gamma interferon (chifn-gamma). d-rnas expressing chifn-gamma were shown to be capable of rescue, replication, and packaging into virions in a helper virus-dependent system following electroporation of in vitro-derive ...200312719562
a recombinant fowl adenovirus expressing the s1 gene of infectious bronchitis virus protects against challenge with infectious bronchitis virus.the spike peplomer s1 subunit sequence from avian infectious bronchitis virus (ibv) vic s strain was expressed in a plasmid under the control of the fowl adenovirus (fav) major late promoter (mlp). two recombinants were constructed in fav serotype 8 (fav 8) by inserting the expression cassette between the snabi and xbai restriction enzyme sites (clone da3) or between the spei sites (clone ca6-20). expression of the s1 gene in the recombinants was confirmed by reverse transcription-polymerase cha ...200312798610
in vitro compatibility of an anticoccidial vaccine with live infectious bronchitis and live newcastle disease vaccines. 200312825705
emergence of a coronavirus infectious bronchitis virus mutant with a truncated 3b gene: functional characterization of the 3b protein in pathogenesis and replication.the subgenomic rna 3 of ibv has been shown to be a tricistronic mrna, encoding three products in ibv-infected cells. to explore if the least expressed orf, orf 3b, which encodes a nonstructural protein, is evolutionarily conserved and functionally indispensable for viral propagation in cultured cells, the beaudette strain of ibv was propagated in chicken embryonated eggs for three passages and then adapted to a monkey kidney cell line, vero. the 3b gene of passage 3 in embryonated eggs and passa ...200312832199
recombinant avian infectious bronchitis virus expressing a heterologous spike gene demonstrates that the spike protein is a determinant of cell tropism.a recombinant infectious bronchitis virus (ibv), beaur-m41(s), was generated using our reverse genetics system (r. casais, v. thiel, s. g. siddell, d. cavanagh, and p. britton, j. virol. 75:12359-12369, 2001), in which the ectodomain region of the spike gene from ibv m41-ck replaced the corresponding region of the ibv beaudette genome. beaur-m41(s) acquired the same cell tropism phenotype as ibv m41-ck in four different cell types, demonstrating that the ibv spike glycoprotein is a determinant o ...200312885925
expression of immunogenic s1 glycoprotein of infectious bronchitis virus in transgenic potatoes.the expression of infectious bronchitis virus (ibv) s1 glycoprotein in potatoes and its immunogenicity in mice and chickens were investigated. potato plants were genetically transformed with a cdna construct encoding the ibv s1 glycoprotein with the agrobacterium system. genomic dna and mrna analyses of the transformed plantlets confirmed the integration of the foreign cdna into the potato genome, as well as its transcription. mice and chickens vaccinated with the expressed ibv s1 glycoprotein p ...200312885926
protection of chickens from infectious bronchitis by in ovo and intramuscular vaccination with a dna vaccine expressing the s1 glycoprotein.we have constructed a dna vaccine (pdkarks1-dpi) expressing the s1 glycoprotein (arkansas dpi) of infectious bronchitis virus (ibv) to examine protective immunity after in ovo and intramuscular dna immunization. birds receiving in ovo dna followed by live virus vaccination at 2 wk of age were 100% protected from clinical disease. birds receiving only live virus vaccine or only in ovo dna vaccination were < or = 80% protected. ibv was detected up to 10 days postchallenge in unvaccinated control g ...200312887187
evaluation of the non-temperature-sensitive field clonal isolates of the mycoplasma synoviae vaccine strain ms-h.the live attenuated temperature-sensitive (ts+) mycoplasma synovia (ms) strain, ms-h, is used as a vaccine in a number of countries to control virulent ms infection in commercial chicken flocks. nine out of 50 isolates made from flocks vaccinated with ms-h were found to have lost the ts+ phenotype of the original vaccine strain. in order to examine the influence of the ts- phenotype on virulence of the isolates, four of the ts- isolates, the ms-h vaccine, and the vaccine parent strain 86079/7ns ...200312887194
the cytoplasmic tails of infectious bronchitis virus e and m proteins mediate their interaction.virus-like particle (vlp) formation by the coronavirus e and m proteins suggests that interactions between these proteins play a critical role in coronavirus assembly. we studied interactions between the infectious bronchitis virus (ibv) e and m proteins using in vivo crosslinking and vlp assembly assays. we show that ibv e and m can be crosslinked to each other in ibv-infected and transfected cells, indicating that they interact. the cytoplasmic tails of both proteins are important for this int ...200312890618
genetic diversity of avian infectious bronchitis virus california variants isolated between 1988 and 2001 based on the s1 subunit of the spike glycoprotein.twenty-nine isolates of avian infectious bronchitis virus (ibv) recovered from commercial chicken flocks in california between 1988 and 2001 and identified as california variants by serotype and direct automated cycle sequencing of the ibv spike glycoprotein s1 subunit, were further characterized phylogenetically and by nucleotide sequence comparison. california variants were grouped according to production type of chicken, by comparison with public access sequence databases (ncbi genbank and em ...200312536299
in vivo thymulin treatments enhance avian lung natural killer cell cytotoxicity in response to infectious bronchitis virus.previous work has shown that in vitro thymulin treatments have the ability to enhance natural killer (nk) cell cytotoxicity. the purpose of the experiments presented here was to examine the in vivo effects of thymulin on avian nk cell activity in response to a viral infection. five and a half-week-old k-strain chickens infected with avian infectious bronchitis virus (ibv) served as the model for these experiments. daily thymulin injections began at varying time points prior to or post-infection. ...200312538040
hematology, plasma biochemistry, and serosurvey for selected infectious agents in southern giant petrels from patagonia, argentina.in conjunction with reproductive and feeding ecology studies on southern giant petrels (sgp, macronectes giganteus) blood samples were collected for baseline health evaluations. twenty-five adult sgp from a breeding colony in chubut, argentina, were sampled during two consecutive breeding seasons, 1999-2000 (n = 15) and 2000-01 (n = 10). values for hematology, plasma biochemistry, and minerals are described for 20 birds in apparent good physical condition. a serologic survey of exposure to selec ...200312910764
typing of field isolates of infectious bronchitis virus based on the sequence of the hypervariable region in the s1 gene.a universal primer set was developed that amplifies a region covering hypervariable region (hvr) 1 and hvr 2 in the s1 gene of the infectious bronchitis virus (ibv). the universality of this primer set was confirmed by testing the reference strains of different serotypes or variants of the ibv present in the united states. an approximately 450-bp region containing hvr 1 and hvr 2 of 7 untyped field isolates obtained in 1999 and 2000 was amplified. direct sequencing followed by phylogenetic analy ...200312918815
ability of massachusetts-type infectious bronchitis virus to increase colibacillosis susceptibility in commercial broilers: a comparison between vaccine and virulent field virus.the abilities of massachusetts-type vaccine virus and virulent infectious bronchitis (ib) field virus to increase colibacillosis susceptibility were compared. in four experiments, 29-day-old female commercial broilers housed in isolators, were infected intratracheally and oculonasally with ib vaccine strains (h120 and h52) or virulent ib field strains (d387 and m41) (4.8 or 6.8 log(10) median embryo infective dose, per broiler). five days later, escherichia coli 506 strain was given intratrachea ...200314522702
evaluation of a nucleoprotein-based enzyme-linked immunosorbent assay for the detection of antibodies against infectious bronchitis virus.as an immunogen of the coronavirus, the nucleoprotein (n) is a potential antigen for the serological monitoring of infectious bronchitis virus (ibv). in this report, recombinant n protein from the beaudette strain of ibv was produced and purified from escherichia coli as well as sf9 (insect) cells, and used for the coating of enzyme-linked immunosorbent assay (elisa) plates. the n protein produced in sf9 cells was phosphorylated whereas n protein from e. coli was not. our data indicated that n p ...200314522708
establishment of persistent avian infectious bronchitis virus infection in antibody-free and antibody-positive chickens.avian infectious bronchitis virus (ibv) causes a highly contagious and economically significant disease in chickens. establishment of a carrier state in ibv infection and the potential for the persistent virus to undergo mutations and recombination in chicken tissues have important consequences for disease management. nevertheless, whether chickens can maintain persistent ibv infection in the absence of reinfection from exogenous sources or the presence of antibody in the host can modulate virus ...200314562886
the effects of avian leukosis virus subgroup j on broiler chicken performance and response to vaccination.the effects of avian leukosis virus subgroup j (alv-j) infection on meat-type chickens reared in a simulated commercial setting were evaluated. each of three alv-j isolates was evaluated with both simulated horizontal transmission (sht) and simulated vertical transmission (svt). mortality, morbidity, disease condemnations, and feed conversions were increased and body weights at processing were decreased in alv-j infected birds as compared to sham inoculated hatch mates. the adverse effects of al ...200314562889
attenuation, safety, and efficacy of an infectious bronchitis virus ga98 serotype vaccine.in 1998, novel strains of infectious bronchitis virus (ibv) were identified in chickens from the southeastern united states and classified as a new serotype designated georgia 98 (ga98). because of the widespread nature of the ga98 virus in the southeastern united states and the lack of adequate protection with the de072 vaccine, we developed a specific vaccine for the ga98 serotype. the ga98/0470/98 isolate of ibv was passaged in embryonating chicken eggs 70 times, and attenuation of the virus ...200314562890
detection of infectious bronchitis virus by real-time reverse transcriptase-polymerase chain reaction and identification of a quasispecies in the beaudette strain.in this report, we describe a real-time reverse transcriptase-polymerase chain reaction (rrt-pcr) diagnostic test for infectious bronchitis virus (ibv) with the use of fluorescence resonance energy transfer (fret) technology. two primers that amplify a 383-base pair product between nucleotide positions 703 and 1086 relative to the start codon for the s1 gene of the massachusetts 41 virus were designed and used to amplify the beaudette, massachusetts 41, florida 18288, connecticut, iowa 97, arkan ...200314562902
characterization of infectious bronchitis virus isolates by slot blot hybridization.we used slot blot hybridization of the hypervariable regions of the s1 subunit of spike peplomer gene to identify and characterize infectious bronchitis virus (ibv) strains. template dna was created from six reference strain ibvs of different serotypes and immobilized on a nitrocellulose membrane. we synthesized digoxigenin-labeled probes from reference and unknown field viruses and hybridized them to template dna. all reference strains could be distinguished and isolates identified by serotype ...200314562903
severe acute respiratory syndrome vaccine development: experiences of vaccination against avian infectious bronchitis coronavirus.vaccines against infectious bronchitis of chickens (gallus gallus domesticus) have arguably been the most successful, and certainly the most widely used, of vaccines for diseases caused by coronaviruses, the others being against bovine, canine, feline and porcine coronaviruses. infectious bronchitis virus (ibv), together with the genetically related coronaviruses of turkey (meleagris gallopovo) and ring-necked pheasant (phasianus colchicus), is a group 3 coronavirus, severe acute respiratory syn ...200314676007
avian influenza (h9n2) outbreak in iran.an epidemic of avian influenza (ai) (h9n2) occurred in broiler chicken farms in iran during 1998-01. mortality between 20% and 60% was commonly observed on the affected farms. mixed infections of the influenza virus with other respiratory pathogens, particularly infectious bronchitis virus and mycoplasma gallisepticum, were thought to be responsible for such high mortality, which resulted in great economic losses. clinical signs included swelling of the periorbital tissues and sinuses, typical r ...200314575072
hematology, plasma chemistry, serology, and chlamydophila status of the waved albatross (phoebastria irrorata) on the galapagos islands.venipuncture was performed on 50 adult, free-ranging waved albatrosses (phoebastria irrorata) on española, galapagos islands, ecuador, to establish hematologic and plasma biochemistry reference ranges and to determine the prevalence of exposure to important domestic avian pathogens. weights and plasma creatine phosphokinase activities differed significantly between males and females. serum was tested for evidence of exposure to avian influenza, avian paramyxoviruses 1, 2, and 3, avian cholera, a ...200314582791
[transgenic potato containing immunogenic gene of avian coronavirus and its immunogenicity in mice].to check the feasibility of expression of the immunogenic gene of avian coronavirus infectious bronchitis virus (ibv) in plants, the transformation of s1 gene of ibv into potato and the immunogenicity of its expression product was studied. the s1 gene of ibv-zj971 strain was inserted into plasmid pbi121 under the control of 35 s promoter. agrobacterium fumefaciens eha105 with the recombinant vector pbi121 was obtained by tri-parental mating method. so, an efficient potato transformation system m ...200314614539
a reverse transcriptase-polymerase chain reaction assay for the diagnosis of turkey coronavirus infection.this study reports on the development of a reverse transcriptase-polymerase chain reaction (rt-pcr) for the specific detection of turkey coronavirus (tcov). of the several sets of primers tested, 1 set of primers derived from the p gene and 2 sets derived from the n gene of tcov could amplify the tcov genome in the infected samples. the rt-pcr was sensitive and specific for tcov and did not amplify other avian rna and dna viruses tested except the infectious bronchitis virus (ibv). to overcome t ...200314667027
a recombination event, induced in ovo, between a low passage infectious bronchitis virus field isolate and a highly embryo adaptedvaccine strain.the possibility of genomic recombination among different strains of infectious bronchitis virus (ibv) was examined in eve by coinfecting specific pathogen free embryonating chicken eggs with commonly used, embryo-adapted vaccine strains of ibv (arkansas, massachusetts, and connecticut), and a delaware-072-like field virus isolated from a layer farm in minnesota. recombination was observed between th e massachusetts and the delaware-072-like strains of the virus. the recombination event was asses ...200314708973
evaluation of the protection conferred by commercial vaccines against the california 99 isolate of infectious bronchitis virus.an infectious bronchitis virus (ibv) was isolated from commercial broilers from the state of california exhibiting respiratory distress, inflamed tracheas, airsaculitis, and edematous lungs. after reverse transcriptase-polymerase chain reaction (rt-pcr), the california isolate exhibited an identical restriction fragment length polymorphism (rflp) pattern to some isolates obtained from california, known as california 99 isolates. commercial mass-conn and mass-ark vaccines were used to vaccinate c ...200314708975
evaluation of pathogenic potential of avian influenza virus serotype h9n2 in chickens.recently seven isolates of avian influenza virus (aiv) serotype h9n2 recovered from an outbreak of ai were analyzed on the basis of their biological and molecular characteristics. all the isolates belonged to the low-pathogenicity group of aiv. to further evaluate their pathogenic potential in association with other organisms, an isolate was inoculated experimentally in chickens using different routes and subsequently challenged with infectious bronchitis virus, ornithobacterium rhinotracheale o ...200314575070
infectious bronchitis virus replication in the chicken embryo related cell line.the susceptibility of the chicken embryo related (cer) cell line to infectious bronchitis virus (ibv m41) was characterized after five consecutive passages in cer cells. virus replication was monitored by cytopathic effect observation, electron microscopy, indirect immunofluorescence, and reverse transcription polymerase chain reaction (rt-pcr). at 96 h post-infection (p.i.), the cytopathic effect was graded 75% by cell fusion, rounding up of cells and monolayer detachment, and the electron micr ...200317585465
development and use of the h strain of avian infectious bronchitis virus from the netherlands as a vaccine: a review.the h strain of infectious bronchitis (ib) was one of the earliest live attenuated ib vaccines to be developed and has continued to be use in most parts of the world for almost 50 years. it was developed for used at both the 52nd (h52) and 120th (h120) vaccine levels and, because of it ability to provide heterologous cross-protection against a number of ib viruses of different serotypes, has proved to be one of the most enduring live attenuated ib vaccines. in fact, the h120 vaccine is possibly ...200415763721
aerosol-induced mycoplasma synoviae arthritis: the synergistic effect of infectious bronchitis virus infection.the effect of infectious bronchitis virus (ibv) infection (10(4.5) median embryo infective dose per chick) on the induction of mycoplasma synoviae arthritis was investigated. mycoplasma-free brown layer pullets, approximately 5 weeks old, were exposed to an aerosol dose of > or =10(2-3) colony-forming units (cfu) of m. synoviae alone or 3 days after inoculation of a field strain of ibv (d1466) by the ocular-nasal route. chicks injected intravenously with 10(9) cfu m. synoviae served as positive ...200415763728
animal coronavirus vaccines: lessons for sars.severe acute respiratory syndrome (sars) emerged in china and spread globally as a human pandemic. it is caused by a new coronavirus (cov) of suspect animal origin. the emergence of sars stunned medical scientists, but veterinary virologists had previously recognized covs as causing fatal respiratory or enteric disease in animals with interspecies transmission and wildlife reservoirs. because of its public health impact, major efforts are focused on development of sars vaccines. occurrence of co ...200415742624
characterization of an avian infectious bronchitis virus isolated in china from chickens with nephritis.one ibv isolate, sc021202, was isolated from the kidneys of the infected young chickens by inoculating embryonated eggs, and its morphology, physiochemical and haemagglutonating properties were detected. virulence of the isolate sc021202 was determined with specific pathogen-free (spf) chicken inoculation. nucleotide acid sequence of s1 gene of the isolate sc021202 was further sequenced and analysed. the physiochemical and morphological properties of the isolate sc021202 were in accordance to th ...200415228547
avian infectious bronchitis virus: a possible cause of reduced fertility in the rooster.the formation of epididymal stones in the rooster epididymis is a widespread problem that has detrimental effects on sperm production and fertility. the cause of epididymal stones is unknown, but an infectious agent, the avian infectious bronchitis virus (aibv), has been implicated. the goal of this study was to determine if administering the live attenuated aibv vaccine to male chicks increases the incidence of stones in the epididymal region of the adult rooster. specific pathogen free (spf) l ...200415666874
oie white spot syndrome virus pcr gives false-positive results in cherax quadricarinatus.white spot syndrome virus (wssv) is an intranuclear bacilliform virus (ibv) that is a serious, notifiable crustacean pathogen. the office international des epizooties (oie) pcr protocol for wssv uses primer sets initially developed by lo et al. (1996). it yields a first-step pcr amplicon of 1441 bp and a nested pcr amplicon of 941 bp. an amplicon (941 bp) purported to specifically detect wssv was obtained when using template dna extracted from cherax quadricarinatus in a wssv pcr detection proto ...200415672884
evaluation of a safe and sensitive spike protein-based immunofluorescence assay for the detection of antibody responses to sars-cov.previously, we have identified a truncated antigenic fragment named protein c [441 to 700 amino acids (a.a.)] as the immunodominant fragment of spike (s) protein of severe acute respiratory syndrome (sars) coronavirus (sars-cov). we have now successfully expressed protein c using the baculovirus system in s. frugiperda (sf-9) cells. this recombinant baculovirus expressing protein c was first characterized using five sars convalescent human sera and five normal human sera. the results showed that ...200415680149
construction, characterization, and evaluation of the vaccine potential of three genetically defined mutants of avian pathogenic escherichia coli.the delta gale, delta pura, and delta aroa derivatives of avian septicemic escherichia coli ec99 strain (o78 serogroup) were constructed with a suicide vector containing the pir-dependent r6k replicon and the sacb gene of bacillus subtilis. the resultant isogenic mutants were stable and lacked approximately 45%, 36%, and 52% of the genes for gale, pura, and aroa, respectively. the delta pura and delta aroa mutants did not grow on minimal medium, whereas the delta gale mutant grew on minimal medi ...200415283416
phylogenetic analysis of avian infectious bronchitis virus strains isolated in japan.to define the origin and evolution of recent avian infectious bronchitis virus (ibv) in japan, a genetic analysis was performed. by phylogenetic analysis based on the s1 gene including the sequence of the hypervariable regions, ibv isolates in japan were classified into five genetic groups, which included two already-known groups (mass and gray). among them, three major genetic groups were associated with the recent outbreaks of ib in japan. one group is indigenous to japan and could not be plac ...200415290359
nephropathogenesis of chickens experimentally infected with various strains of infectious bronchitis virus.four-day-old specific-pathogen-free chickens were inoculated by eyedrop with four different strains (gray, jmk, cv56b, and wolgemuth) of infectious bronchitis virus (ibv). birds were monitored clinically and euthanatized at 1, 4, 7, and 14 days postinfection and tissues were collected for virus isolation, histopathologic examination, in situ hybridization (ish), and immunohistochemistry (ihc). clinical disease was severe in chickens infected with wolgemuth, but no overt disease was observed with ...200415297756
a single amino acid mutation in the spike protein of coronavirus infectious bronchitis virus hampers its maturation and incorporation into virions at the nonpermissive temperature.the spike (s) glycoprotein of coronavirus is responsible for receptor binding and membrane fusion. a number of variants with deletions and mutations in the s protein have been isolated from naturally and persistently infected animals and tissue cultures. here, we report the emergence and isolation of two temperature sensitive (ts) mutants and a revertant in the process of cold-adaptation of coronavirus infectious bronchitis virus (ibv) to a monkey kidney cell line. the complete sequences of wild ...200415302214
complete sequences of 3' end coding region for structural protein genes of turkey coronavirus.overlapping fragments of genomic rna spanning 6963 nucleotides from 5' end of spike (s) protein gene to 3' end of nucleocapsid (n) protein gene of turkey coronavirus (tcov) were amplified by reverse-transcription-polymerase chain reaction (rt-pcr). the primers were derived from the corresponding sequences of infectious bronchitis virus (ibv). the pcr products were cloned and sequenced and their nucleic acid structure and similarity to published sequences of other coronaviruses were analyzed. seq ...200415522448
s1 and n gene analysis of avian infectious bronchitis viruses in taiwan.the disease caused by infectious bronchitis virus (ibv) produces great economic for the poultry industry. the purpose of this study is to investigate the molecular epidemiology of ibv in taiwan. an old ibv strain isolated in 1964 and another 31 strains isolated from 1991 to 2003 were selected for n-terminal s1 gene analysis. based on their phylogenetic tree, 13 strains were selected for sequencing the entire s1 and partial nucleocapsid (n) genes. the results indicated that taiwanese ibv strains ...200415529980
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1001 - 1100 of 2354