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cloning and characterization of a putative cytadhesin gene (mgc1) from mycoplasma gallisepticum.a 150-kda cytadhesin-like protein from mycoplasma gallisepticum has been identified. a previously described 583-bp fragment (j.e. dohms, l.l. hnatow, p. whetzel, r. morgan and c.l. keeler, jr., avian dis. 37:380-388, 1993) was used to probe a genomic library of m. gallisepticum dna. an 8.0-kb saci fragment was identified, cloned, and partially sequenced. analysis of the resulting 3,750-bp sequence revealed the presence of a 3,366-nucleotide open reading frame, mgc1. the 1,122-amino-acid protein ...19968613358
size and genomic location of the pmga multigene family of mycoplasma gallisepticum.the pmga multigene family encodes variant copies of the cell surface haemagglutinin of mycoplasma gallisepticum. quantitative southern blotting, using an oligonucleotide probe complementary to a region conserved in the leader sequence of all known pmga genes, was used to estimate the number of members of the family in the genome of seven strains of m. gallisepticum. the number of copies estimated to be present in the genome varied from 32 in strain f to 70 in strain r, indicating that the pmga g ...19968704982
identification of mycoplasma membrane proteins by systematic tn phoa mutagenesis of a recombinant library.wall-less prokaryotes in the genus mycoplasma include over 90 species of infectious agents whose pathogenicity for humans and other animals is currently being assessed. molecular characterization of surface proteins is critical in this regard but is hampered by the lack of genetic systems in these organisms. we used tnphoa transposition to systematically mutagenize, in escherichia coli, a genomic plasmid library constructed from mycoplasma fermentans, a potential human pathogen. the strategy cir ...19958709847
comparison of enzyme-linked immunosorbent assay and hemagglutination-inhibition for detection of antibody to mycoplasma gallisepticum in commercial broiler, fair and exhibition, and experimentally infected birds.hemagglutination-inhibition (hi) assay and a new affinity-purified enzyme-linked immunosorbent assay (elisa) for detection of antibody to mycoplasma gallisepticum (mg) compared for use as confirmatory tests for the national poultry improvement plan program. samples from three different poultry populations with different prevalences of mg infection were studied: commercial broiler breeder birds (low prevalence of infection), fair and exhibition birds (moderate prevalence of infection), and experi ...19968713026
polymerase chain reaction optimization for mycoplasma gallisepticum and m. synoviae diagnosis.mycoplasma gallisepticum- or m. synoviae-challenged chickens were monitored with serological assays (serum plate agglutination, hemagglutination inhibition, and enzyme-linked immunosorbent assay) and polymerase chain reaction (pcr). the tracheal swabs from m. gallisepticum-challenged chickens received three different treatments (phosphate-buffered saline [pbs], frey's broth, or 10 mm tris-hcl/250 mm ethylenediaminetetraacetic acid/ 2.5% sodium dodecyl sulfate [ste]) prior to dna purification. a ...19968713037
development of a polymerase chain reaction and a nonradioactive dna probe for infectious laryngotracheitis virus.the polymerase chain reaction (pcr) was developed using infectious laryngotracheitis virus (iltv) primers made from a portion of the iltv thymidine kinase gene. dna from various iltv field isolates, from the usda challenge strain of iltv, and from commercial iltv vaccines was specifically amplified. no amplification occurred using template dna from uninfected chicken-embryo liver cells (celc), several nonavian alphaher-pesviruses, mycoplasma gallisepticum, mycoplasma synoviae, pasteurella hemoly ...19968713048
[determination of the nucleotide sequence of the part of the mycoplasma gallisepticum genome, containing the rpob gene, during the use of the bal-ptm method for obtaining sequential deletions of the sequenced fragment]. 19968714123
application of polymerase chain reaction with arbitrary primers to strain identification of mycoplasma gallisepticum.dna heterogeneity among strains and isolates of mycoplasma gallisepticum (mg) was demonstrated with the arbitrarily primed polymerase chain reaction (ap-pcr) method. this method involves three cycles of low-stringency amplification followed by pcr at higher stringency. reproducible dna fragments of 25 different mg strains or isolates were generated with three arbitrarily chosen primers. the mg strains or isolates were distinguished according to the banding patterns of their amplified dna on agar ...19958719206
evaluation of enrofloxacin against egg transmission of mycoplasma gallisepticum.five groups of 20 commercial leghorn hens near peak production were challenged with mycoplasma gallisepticum, and medicated with enrofloxacin in the drinking water at 7-11, 21-25, or 7-11 and 21-25 days postchallenge (pc), a combination of lincomycin/spectinomycin at 7-11 and 21-25 days pc, or left as untreated controls. egg production records were maintained, and all eggs produced during the 63 days following challenge were incubated for 18 days and then cultured for m. gallisepticum. all group ...19958719217
[a physical map of mycoplasma gallisepticum strain a5969 genome and determination of its positions on certain genes]. 19968754006
california national animal health monitoring system for meat turkey flocks-1988-89 pilot study: management practices, flock health, and production.a pilot project for a meat turkey national animal health monitoring system was undertaken in california in 1988-89 to explore data gathering techniques and to estimate the frequency, magnitude, and variability of management, flock health (including administration of pharmaceuticals for prevention and treatment of disease), and production variables in order to facilitate planning for future food animal monitoring systems. enteritis, which occurred in over one-third of the flocks, and colibacillos ...19968790875
the minimum inhibitory concentration of tilmicosin and tylosin for mycoplasma gallisepticum and mycoplasma synoviae and a comparison of their efficacy in the control of mycoplasma gallisepticum infection in broiler chicks.the minimum inhibitory concentrations of tylosin tartrate and a new macrolid antimicrobial agent, tilmicosin, were assessed for six strains of mycoplasma gallisepticum (mg) and three strains of mycoplasma synoviae (ms) in vitro by the microbroth method. for four of the strains of mg, tilmicosin showed a slightly lower minimum inhibitory concentration (mic) than did tylosin at both the initial reading (when ph 7.0 is first seen in the dilutions under test) and the final reading at 14 days of incu ...19968790882
field investigation of mycoplasma gallisepticum infections in house finches (carpodacus mexicanus) from maryland and georgia.a field study investigating the occurrence of mycoplasma gallisepticum (mg) in house finches (carpodacus mexicanus) was conducted in maryland and georgia. eighty-eight finches were captured and examined grossly and microscopically for mg-related conjunctivitis. serum samples were obtained for serum plate agglutination (spa) and hemagglutination inhibition (hi) testing. swabs from conjunctiva, sinus, and choanal cleft were inoculated into two mycoplasma broth media for culture and polymerase chai ...19968790883
development and application of dna probes and pcr tests for haemophilus paragallinarum.a genomic dna library of haemophilus paragallinarum strain modesto was created. screening of this library identified four clones that reacted specifically with all 56 isolates of h. paragallinarum tested and failed to react with 24 closely related bacteria from the genera pasteurella and actinobacillus. all four clones also failed to react with dna extracted from one field isolate each of mycoplasma gallisepticum and mycoplasma synoviae. the probes based on these four clones were approximately 1 ...19968790892
experimental reproduction of mycoplasma gallisepticum disease in chukar partridges (alectoris graeca).an outbreak of conjunctivitis and severe respiratory disease occurred in an integrated chukar partridge (alectoris graeca) operation that involved about 8000 birds. the main clinical features were conjunctivitis and sinusitis and frequent mouth breathing, but almost no gasping or coughing. in 1000 breeders, egg production declined from 73% to 20%. morbidity reached 100%, and losses from mortality and culling approached 60%. at necropsy, a conjunctivitis (often bilateral) and extensive caseated s ...19968790893
mycoplasma gallisepticum isolated from house finches (carpodacus mexicanus) with conjunctivitis.an epornitic of conjunctivitis in free-flying house finches (carpodacus mexicanus) occurred in several mid-atlantic and eastern states of the usa in 1994. clinical signs and gross lesions ranged from mild to severe unilateral or bilateral conjunctival swelling with serous to mucopurulent drainage and nasal exudate. microscopic lesions consisted of chronic lymphoplasmacytic conjunctivitis, rhinitis, and sinusitis. notably slow-growing mycoplasmas were isolated from conjunctival and/or infraorbita ...19968790904
detection of mycoplasma gallisepticum antibodiesin the sera of village chickens by the enzyme-linked immunosorbent assay. 19968809982
purification of mycoplasma gallisepticum membrane proteins p52, p67 (pmga), and p77 by high-performance liquid chromatography.the plasma membrane of the avian pathogen mycoplasma gallisepticum contains about 200 polypeptides including the major lipoprotein pmga. we have developed a simple and efficient procedure for the purification of three membrane proteins of this wall-less bacterium. proteins were selectively extracted from isolated plasma membranes with the mild zwitterionic detergent (n-dodecyl-n,n-dimethylammonio) undecanoate (ddmau) and subjected to size-exclusion chromatography (fplc) in the presence of the sa ...19968812852
protective immunity induced in chicken by a single immunization with mycoplasma gallisepticum immunostimulating complexes (iscoms).an experimental immunostimulating complex vaccine has been prepared from detergent (mega-10) solubilized mycoplasma gallisepticum (mg) antigens. sucrose gradient centrifugation, sds-page and immunoblotting studies demonstrated that the iscom vaccine contained virtually all of the immunodominant mg membrane proteins, including p64 and p56. protective immunity generated by the experimental mg iscom vaccine was demonstrated in challenge experiments. chickens immunized with a single dose containing ...19968843631
optimising the conditions for isolation of mycoplasma gallisepticum collected on applicator swabs.an experiment to compare the recovery of mycoplasma gallisepticum (mg) on dry swabs and swabs wet with mycoplasma broth (mb) was carried out by swabbing choanal clefts of mg infected turkey poults at days 3, 6, 9, 12 post-infection. wet swabs yielded significantly greater numbers of mycoplasmas than dry swabs on three out of four sampling days. when low numbers of mycoplasmas were collected on wet or dry swabs (in vitro) and then stored at room temperature (rt) or 4 degrees c for various interva ...19968861642
monoclonal antibodies specific to mycoplasma iowae.monoclonal antibodies (mabs) against mycoplasma iowae (mi) were produced to identify common immunogenic determinants shared between antigenically heterogenous mi. twenty-four mabs were produced against mi. with western immunoblotting, all 24 mabs recognized a 45,000-mw protein (p45) of mi strain i-695. one of the mabs characterized, mab 2c, identified p45 antigen in western immunoblots with six laboratory strains and 24 field isolates of mi. mab 2c did not cross-react with mycoplasma galliseptic ...19968883792
standardized method of aerosol challenge for testing the efficacy of mycoplasma gallisepticum vaccines.a special chamber was constructed with the goal of controlling the process of aerosol infection of chickens with mycoplasma gallisepticum (mg). the virulent australian mg field strain ap3as was used in each of three experiments. the response to infection of layer-strain pullets was measured serologically, by the incidence and severity of gross lesions in tracheas and air sacs, and by the relative numbers of mg isolated from tracheas and air sacs 2 wk after challenge. in two of the experiments tr ...19968883797
bioadhesion of lectin-latex conjugates to rat intestinal mucosa.the specific interactions between three lectin-latex conjugates and different structures of rat intestinal mucosa have been studied ex vivo.19968956340
antibody responses of chickens to inoculation with mycoplasma gallisepticum membrane proteins in immunostimulating complexes.membrane proteins of mycoplasma gallisepticum (mg) strain r were extracted with the detergent mega-10 and incorporated into immunostimulating complexes (iscoms). a membrane protein of approximately 64 kd (p64) molecular weight was a major component of mg iscoms. six-week-old specific-pathogen-free leghorn chickens were inoculated by various routes (subcutaneous; combined intranasal and eyedrop; and combined subcutaneous, intranasal, and eyedrop) with 10 micrograms mg proteins in iscoms, or inocu ...19968980811
use of species-specific oligonucleotide probes to detect mycoplasma gallisepticum, m. synoviae, and m. iowae pcr amplification products.three digoxigenin-labeled oligonucleotide probes, complementary to the variable region of the 16s ribosomal rna (rrna) gene of mycoplasma gallisepticum, m. synoviae, and m. iowae were designed. the oligonucleotides were used in a dot blot hybridization assay. the target dna is a 780-bp fragment of the 16s rrna gene of avian mycoplasmas amplified by a single set of primers (multispecies polymerase chain reaction [pcr]). the oligonucleotide probes were specific for their corresponding pcr products ...19969026082
identification of mycoplasma isolates by elisa.an antigen-based enzyme-linked immunosorbent assay (elisa) was developed for the rapid identification of mycoplasma gallisepticum and mycoplasma synoviae. two trials were conducted to compare the elisa with the conventional fluorescent antibody technique. in trial 1, broilers were inoculated with m. gallisepticum f, m. gallisepticum s6, and m. synoviae. in trial 2, hens were inoculated with m. gallisepticum f, m. synoviae, and a combination of the two. swab isolates were obtained from the choana ...19979087324
transmissibility of live mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from vaccinated layer pullets to sentinel poultry.in separate trials, layer pullets were vaccinated with mycoplasma gallisepticum (mg) strain 6/85 or strain ts-11 commercially produced live vaccines. for a 15-wk postvaccination (pv) period, vaccinates were commingled with unvaccinated pullets and were in indirect contact with sentinel groups of pullets, broiler breeders, turkey breeders, or meat turkeys in adjoining pens. infectivity and transmissibility of vaccine strains were determined by tracheal culture and serology at 1 wk followed by 3-w ...19979087336
mycoplasmal conjunctivitis in wild songbirds: the spread of a new contagious disease in a mobile host population.a new mycoplasmal conjunctivitis was first reported in wild house finches (carpodacus mexicanus) in early 1994. the causative agent was identified as mycoplasma gallisepticum (mg), a nonzoonotic pathogen of poultry that had not been associated with disease in wild songbirds. since the initial observations of affected house finches in the mid-atlantic region, the disease has become widespread and has been reported throughout the eastern united states and canada. by late 1995, mycoplasmal conjunct ...19979126448
mycoplasmal conjunctivitis in a european starling.bilateral conjunctivitis and episcleritis were identified in an adult european starling (sturnus vulgaris). a novel mycoplasma species, mycoplasma sturni, was isolated in pure culture from the conjunctiva of both eyes. the clinical presentation was similar to that of conjunctivitis in house finches (carpodacus mexicanus) caused by mycoplasma gallisepticum. however, the histologic lesions were distinct, by the presence of ulceration and by the absence of epithelial hyperplasia and lymphoplasmacyt ...19979131571
adherence of mycoplasma gallisepticum involves variable surface membrane proteins.adherence of mycoplasma gallisepticum to erythrocytes was examined by colony immunoblotting, detergent phase fractionation, trypsin treatment, comparison of protein profiles, and comparison of erythrocyte-bound mycoplasma protein fractions of hemadsorption-positive and -negative mutants. the binding of m. gallisepticum to chicken or human erythrocytes was found to be mediated via surface-exposed membrane proteins undergoing high-frequency phase variation.19979169793
mycoplasmoses in poultry.the most important mycoplasmas isolated from domestic avian species include mycoplasma gallisepticum (mg), m. synoviae (ms), m. meleagridis (mm) and m. iowae (mi). mg causes chronic respiratory disease of chickens and infectious sinusitis in turkeys, resulting in economic losses. ms causes infectious synovitis or mild upper respiratory disease. mm infects only turkeys, causing airsacculitis and sub-optimal production and hatchability. mi is associated with reduced hatchability in turkey flocks. ...19969190023
control of avian mycoplasmoses by vaccination.vaccination is an option for controlling mycoplasma gallisepticum or m. synoviae when biosecurity measures fail to prevent the infection of poultry flocks with these mycoplasmas. both killed vaccines (bacterins) and living vaccines are currently in commercial use. bacterins usually contain an oil emulsion adjuvant and are administered by subcutaneous or intramuscular injection. they can reduce the decline in egg production associated with m. gallisepticum, although they do not prevent infection. ...19969190024
avian mycoplasmosis in asia.since 1954, avian mycoplasmosis has been considered a significant problem in chicken flocks in japan and in other asian countries. in japan, mycoplasma gallisepticum (mg) and m. synoviae (ms) infections were confirmed aetiologically in chicken flocks affected with respiratory disease or synovitis in 1962 and 1973, respectively. in other asian countries, including indonesia, the people's republic of china, korea, malaysia, the philippines, taipei china and thailand, the occurrence of mycoplasmosi ...19969190025
epitope diversity of f strain mycoplasma gallisepticum detected by flow cytometry.a culture of f strain mycoplasma gallisepticum (f-mg) that exhibited an epitope identified by monoclonal antibody (mab) 6f10 was used to inoculate leghorn hens in two different trials. in trial 1, mature hens chronically infected with f-mg were swabbed at intervals from 230 to 345 days postinoculation (pi). the f-mg isolates were tested with an agar plate fluorescent antibody (apfa) method that used a polyclonal antibody and with a flow cytometry (pc) technique that used mab 6f10. primary cultur ...19979201390
multiplex pcr for avian pathogenic mycoplasmas.mycoplasma infections are of great concern in avian medicine, because they cause economic losses in commercial poultry production. a multiplex polymerase chain reaction (pcr) was optimized to simultaneously detect four pathogenic species of avian mycoplasmas. four sets of oligonucleotide primers specific for mycoplasma gallisepticum (mg), m. synoviae (ms), m. meleagridis (mm) and m. iowae (mi) were used in the test. by using agarose gel electrophoreses for detection of the pcr-amplified dna prod ...19979232620
application of a nonlinear regression function to evaluate the kinetics of antibody response to vaccines in chicken lines divergently selected for multitrait immune response.to evaluate the kinetics of immune response to vaccines in chickens, antibody response curves were approximated to the observed antibody ratios by using a nonlinear regression function. new parameters, the curve maximum (ymax) and the time of the maximum (tmax), were calculated. the method was applied to analyze the kinetics of the serum antibody response to mycoplasma gallisepticum (mg) and pasteurella multocida (pm) vaccines in white leghorn lines selected, in replicate, for 10 generations for ...19979276887
changing expectations in the control of mycoplasma gallisepticum.mycoplasma gallisepticum (mg) is traditionally controlled by maintaining mg-free flocks on single-age production sites and maintaining them mg-free utilizing good biosecurity and a consistent serological monitoring program. in recent years, several changes have taken place which have changed our ways about thinking about mg control. there have been significant improvements in detection methods. for example, polymerase chain reaction now represents a rapid and sensitive method for detecting the o ...19979276990
dna amplification methods for diagnosis and epidemiological investigations of avian mycoplasmosis.rapid, sensitive and specific tests that detect nucleic acid from pathogenic mycoplasmas are very attractive for the laboratory detection of infected flocks, and methods for direct detection of the four main pathogenic mycoplasmas have been developed. moreover, most avian mycoplasma species can be differentiated, according to their unique restriction fragment length polymorphism (rflp) patterns generated with different restriction enzymes. however, this method is limited to the identification of ...19979276996
molecular epidemiologic investigations of mycoplasma gallisepticum conjunctivitis in songbirds by random amplified polymorphic dna analyses.an ongoing outbreak of conjunctivitis in free-ranging house finches (carpodacus mexicanus) began in 1994 in the eastern united states. bacterial organisms identified as mycoplasma gallisepticum (mg) were isolated from lesions of infected birds. mg was also isolated from a blue jay (cyanocitta cristata) that contracted conjunctivitis after being housed in a cage previously occupied by house finches with conjunctivitis, and from free-ranging american goldfinches (carduelis tristis) in north caroli ...19979284386
antibody-mediated selection of a mycoplasma gallisepticum phenotype expressing variable proteins.a variant phenotype of mycoplasma gallisepticum s6 was isolated from an in vitro antibody-culture system utilizing metabolism-inhibiting antibodies against the 64 kda lipoprotein (lp64). m. gallisepticum populations grown in medium alone or medium containing normal rabbit serum maintained expression of the parental phenotype. this paper describes the identification of proteins which undergo variable expression. several of these were integral membrane proteins, with estimated molecular masses of ...19979345761
various blood parameters in commercial hens acutely and chronically infected with mycoplasma gallisepticum and mycoplasma synoviae.two trials were conducted to study the effects of acute (trial 1) and chronic (trial 2) mycoplasma infections on differential leukocyte counts in chickens. the trials initially included either 20 (trial 1) or 40 (trial 2) 6-wk-old commercial leghorn chickens negative for antibodies to mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms). chickens were inoculated with f strain mg (fmg), ms (wvu 1853), or both. one group of chickens remained uninoculated and served as a negative control for ...19979356698
detection and identification of avian mycoplasmas by polymerase chain reaction and restriction fragment length polymorphism assay.the polymerase chain reaction (pcr) with primers complementary to the 16s rrna genes was used to detect avian mycoplasmas. a primer pair designed for the detection of human and rodent mycoplasmal species was examined for its ability to detect the most important avian mycoplasmas. after testing the respective reference strains, we found that mycoplasma iowae, mycoplasma meleagridis and mycoplasma synoviae could be detected by pcr with this primer pair, and distinction could be made among them by ...19979451458
efficacy of tilmicosin in the control of experimental mycoplasma gallisepticum infection in chickens.this study was conducted to evaluate the efficacy of 5-day, "in water" tilmicosin medication for the prevention of experimental mycoplasma gallisepticum (mg) disease in 10-day-old specific-pathogen-free (spf) chickens. birds were inoculated intratracheally and into the sinus with the mg r-p10 strain. a limited dose titration of the antibiotic over the expected effective range was included, using six groups of 60 birds each: ui: uninfected untreated group; iut: infected untreated group; it1 to it ...19979454912
the effects of f strain mycoplasma gallisepticum, mycoplasma synoviae, and the dual infection in commercial layer hens over a 44-week laying cycle when challenged before beginning of lay. i. egg production and selected egg quality parameters.in each of two trials, 160 commercial pullets were separated into four treatments with four replicates of 10 chickens in each treatment. forty pullets were designated as controls and received no inoculation; 40 other pullets received f strain mycoplasma gallisepticum (fmg); an additional 40 pullets received mycoplasma synoviae (ms); and the final 40 pullets were inoculated with both fmg and ms (dual). hen-day egg production, egg weight, eggshell strength, haugh unit score, pimpling incidence, an ...19979454916
effect of drinking water containing ammonium chloride or sodium bicarbonate on mycoplasma gallisepticum isolation in experimentally infected broiler chickens.in each of three trials, 150 day-old broiler chicks were eyedrop inoculated with 0.04 ml of high-passage f strain mycoplasma gallisepticum (mg) and housed in biological isolation units at 10 chicks per unit. at 4 wk of age, 50 chickens were designated as controls and remained on tap water (ph 7.30), 50 chickens were provided tap water containing 0.63% ammonium chloride (nh4cl, ph 6.91), and 50 chickens were provided tap water containing 1.26% sodium bicarbonate (nahco3, ph 8.17). fluids were sup ...19979454928
detection of mycoplasma in avian live virus vaccines by polymerase chain reaction.the polymerase chain reaction (pcr) was evaluated to detect mycoplasma contamination of avian live virus vaccines. the specificity of the primers showed that 34 strains belonging to nine species of avian mycoplasma dna could be detected. the sensitivity of pcr to detect mycoplasma dna was 10(0.2) colony forming units (cfu) of mycoplasma synoviae and 10(0.7) cfu of mycoplasma gallisepticum. when m. synoviae and m. gallisepticum were spiked into several avian live virus vaccines, pcr gave a positi ...19979467032
immunoblot examination of humoral response of chickens infected with mycoplasma gallisepticum at various ages.mycoplasma gallisepticum- and mycoplasma synoviae-free chickens were infected with 0.2 ml broth culture of m. gallisepticum strain 1226 intra air sac at 3, 14, 18, 28, 42, 49 and 65 days of age. blood samples were taken 0-5 weeks before infection and 1-6 weeks after infection (depending on age of infection). the antibody response was examined by western blot. as a control of infection, serum plate agglutination test (spa), pathological lesions, and presence of mycoplasma in air sacs were used. a ...19979481517
experimental infection of chickens with an atypical mycoplasma gallisepticum strain: comparison of diagnostic methods.fifteen chickens were inoculated with the atypical mycoplasma gallisepticum (mg) k703 strain. on different dates post inoculation, tracheal swab samples were collected for mycoplasma culture and blood samples were analysed by slide agglutination test (sa) with commercial or homologous antigen and enzyme-linked immunosorbent assay (elisa) with three different kits. results showed that mg isolation rate was low on several sampling dates. the sa with commercial antigen did not yield positive result ...19979491445
national surveillance of poultry diseases in lebanon.from 1992 to mid-1996, a national survey of poultry diseases in lebanon was conducted. this surveillance included meat breeder, layer breeder, commercial layer and chicken broiler flocks. the history, signs, lesions and laboratory tests of poultry were used in the diagnosis of prevalent poultry diseases. culture techniques were used to screen for bacterial diseases; serological techniques and, to a lesser extent, culture techniques were used to diagnose viral diseases; and both serological and c ...19979567302
epidemic mycoplasmal conjunctivitis in house finches from eastern north america.in the winter of 1993-94, house finches (carpodacus mexicanus) with severe conjunctivitis (later shown to be caused by mycoplasma gallisepticum) were first observed in sub-urban washington d.c. (usa) and adjacent states. using a large network of volunteer observers in eastern north america, we were able to track the monthly prevalence of the disease between november 1994 and march 1997. using the information on 24,864 monthly data forms, we describe the very rapid spread of the conjunctivitis ep ...19989577773
risk factors associated with mycoplasmal conjunctivitis in house finches.observations from a citizen-based survey were used to identify potential risk factors associated with mycoplasmal conjunctivitis (mycoplasma gallisepticum) in eastern house finches (carpodacus mexicanus). between november 1994 and october 1996, 778 volunteers provided 7,224 monthly observations at residential bird feeding sites across an eight state region in the eastern usa. information collected by questionnaires included health status of house finches and four sympatric passerine species, typ ...19989577774
natural mycoplasma gallisepticum infection in a captive flock of house finches.naturally-occurring mycoplasmal conjunctivitis is described among 104 wild-caught, and initially seronegative, house finches (carpodacus mexicanus) maintained in captivity for 12 wk during november 1995 through january 1996. finches housed in three pens were monitored for clinical signs, and > or = 10 birds were euthanatized for necropsy and mycoplasma testing every 2 wk. within 2 to 4 wk following initial detection of lesions, > 50% of the birds in each of three pens developed a debilitating di ...19989577775
mycoplasma sturni from blue jays and northern mockingbirds with conjunctivitis in florida.northern mockingbirds (mimus polyglottos) and blue jays (cyanocitta cristata) in a florida (usa) wildlife care facility developed clinical signs and gross lesions suggestive of the ongoing outbreak of mycoplasma gallisepticum (mg) conjunctivitis in house finches (carpodacus mexicanus) and american goldfinches (carduelis tristis). mycoplasmal organisms were cultured from conjunctival/corneal swabs of birds with sinusitis, conjunctivitis, and/or epiphora. all of the isolates tested were identified ...19989577796
expression of two members of the pmga gene family of mycoplasma gallisepticum oscillates and is influenced by pmga-specific antibodies.certain monoclonal antibodies and polyclonal antisera directed to pmga, the major protein of mycoplasma gallisepticum, were tested for the ability to influence the surface phenotype of the cell population which resulted from their inclusion in growth medium. the polyclonal antiserum and one monoclonal antibody (mab 66) resulted in an alteration of surface phenotype; specifically, populations of cells grown either on plates or in broth cultures which contained these reagents ceased the expression ...19989596758
the effects of 1,25-dihydroxycholecalciferol and phytase on the natural phytate phosphorus utilization by laying hens.two experiments were conducted to investigate the effects of supplementing a corn-soybean layer diet with either phytase, 1,25-dihydroxycholecalciferol [1,25-(oh)2d3], or their combination. the basal diet was formulated to contain 3.00% ca and 0.33% total p. in experiment 1, 160, 56-wk-old laying hens were randomly assigned to treatment groups fed either the basal diet alone or diets supplemented with either 600 phytase units (ftu) per kilogram feed, 5 microg 1,25-(oh)2d3/kg feed, or their combi ...19989628533
characterization of mgc2, a mycoplasma gallisepticum cytadhesin with homology to the mycoplasma pneumoniae 30-kilodalton protein p30 and mycoplasma genitalium p32.a second cytadhesin-like protein, mgc2, was identified in the avian respiratory pathogen mycoplasma gallisepticum. the 912-nucleotide mgc2 gene encodes a 32.6-kda protein with 40.9 and 31.4% identity with the m. pneumoniae p30 and m. genitalium p32 cytadhesins, respectively. functional studies with reverse transcription-pcr, immunoblotting, double-sided immunogold labeling, and attachment inhibition assays demonstrated homology to the human mycoplasmal p30 and p32 cytadhesins. these findings sug ...19989632619
multigene families encoding the major hemagglutinins in phylogenetically distinct mycoplasmas.mycoplasma synoviae has two major membrane antigens, mspa and mspb, both of which are phase variable and which may be coordinately involved in adhesion of the organism to erythrocytes. a single gene (vlha) from m. synoviae was characterized, and polypeptides were expressed from nonoverlapping 5' and 3' regions in escherichia coli. the expression product of the vlha 5' region reacted with specific reagents against mspb, while that of the 3' region reacted with specific reagents against mspa. anal ...19989632627
pen trial studies on the use of live vaccines to displace virulent mycoplasma gallisepticum in chickens.groups of 10 8-wk-old chickens that had been vaccinated 4 wk previously with the f strain, ts-11, or 6/85 strain of mycoplasma gallisepticum (mg) were challenged by placing them in contact with 20 chickens that had been previously infected with the virulent r strain of mg. each month, the 10 oldest chickens were removed from each pen and replaced with 10 vaccinated chickens to return the total number of chickens in each pen to 30. chickens were bled and cultured for mg prior to contact challenge ...19989645321
potential for transmission of the finch strain of mycoplasma gallisepticum between house finches and chickens.although mycoplasma gallisepticum (mg) is established in house finch (carpodacus mexicanus) populations in at least 33 states, the potential risk of mg introduction to domestic poultry by infected finches currently is unknown. the objectives of this study were to determine if chickens could be infected with the finch strain of mg via direct, across-wire, and proximity (across-room) contact with naturally infected house finches and to determine if house finches could be infected through direct co ...19989645326
serologic incidence of some diseases in kansas wild turkeys.wild turkeys (meleagris gallopavo, n = 1164) were tested for mycoplasma gallisepticum, mycoplasma meleagridis, mycoplasma synoviae, and salmonella pullorum from 1990 to 1997. although 3.3% of the turkeys were suspect for one or more diseases, only 0.9% were serologically positive for m. gallisepticum. these 11 positives were all from one country in south-central kansas.19989645333
eradication of live f strain mycoplasma gallisepticum vaccine using live ts-11 on a multiage commercial layer farm.subsequent to use of a live mycoplasma gallisepticum (mg) vaccination program, the f strain of mg had been circulating on a commercial layer farm since 1981. in 1994, the ts-11 strain was introduced on the farm; each new placement flock was vaccinated by eyedrop with ts-11 for one production cycle, and then all subsequent placement flocks were left unvaccinated. birds were monitored by culture and serology before and after vaccination. mg isolates were characterized by random amplified polymorph ...19989645335
pasteurella multocida infection involving cranial air spaces in white leghorn chickens.seven 18-wk-old pullets from a commercial layer flock experiencing increased mortality associated with neurologic and respiratory symptoms were submitted to the california veterinary diagnostic laboratory system at the turlock branch for necropsy. clinical signs included depression, torticollis, swollen eyelids, conjunctivitis, and sinusitis. meningoencephalitis and suppurative inflammation of the cranial air spaces were found on histopathology. the brain, sinuses, and air spaces of the cranium ...19989645337
evaluation of an enrofloxacin-treatment program against mycoplasma gallisepticum infection in broilers.three chicken broiler breeder flocks, 7 months of age, were confirmed to have mycoplasma gallisepticum (mg) infection, based on culture of tracheal swabs. a total of fifty-five 7-day-old embryos from the three mg-positive flocks had an average 27.4% prevalence of mg-infection in their vitelline membrane. sixty randomly selected mg isolates (30 from individual tracheas of breeders and another 30 from individual vitelline membrane of embryos) were highly sensitive in vitro to enrofloxacin (100%). ...19989646333
comparison of serological tests for detection of mycoplasma gallisepticum antibodies in eggs and chicks hatched from experimentally infected hens.specific pathogen free hens and males were experimentally infected with mycoplasma gallisepticum. eggs were then collected, and a part was incubated and set for hatching. mycoplasma cultures were performed on infected adults and antibodies to mg were analysed by use of slide agglutination (sa) test and commercial elisa tests on adults and chicks sera and on yolks from non incubated eggs. both elisa tests could detect antibodies in yolks from non incubated eggs laid three weeks after infection. s ...19989646451
efficacy of difloxacin in growing broiler chickens for the control of infection due to pathogenic mycoplasma gallisepticum.chickens 14 days old were experimentally inoculated with mycoplasma gallisepticum (mg) r-p10 strain. after development of respiratory symptoms, birds were left unmedicated or medicated for 5 consecutive days with difloxacin 5, 7.5 or 10 mg/kg body weight per day or enrofloxacin at the dose level of 10 mg/kg body weight per day. evaluation of efficacy was based on body weight, symptoms, post-mortem findings, re-isolation of mg and serology. results indicated that under the conditions of this expe ...19989673582
identification and characterization of hu protein from mycoplasma gallisepticum.a hypothetical orf of mycoplasma gallisepticum with a putative 99-amino-acid product (orf99) was noted previously in the upstream region from the type ii topoisomerase gene. the amino acid sequence shows weak homology with the escherichia coli histone-like protein hu. to identify and characterize the protein product of orf99, we prepared mouse antiserum against recombinant gst-orf99 fusion protein. the antiserum reacted with an 11-kda peptide in the crude cell extract of m. gallisepticum, indica ...19989705829
mycoplasmas in the etiology of multifactorial respiratory disease.the avian mycoplasmas pathogenic for commercial poultry, mycoplasma gallisepticum and mycoplasma synoviae in chickens and turkeys, and mycoplasma meleagridis and mycoplasma iowae in turkeys are egg-transmitted infections and exhibit wide variations in clinical manifestations. mycoplasma gallisepticum strains vary widely in virulence, tissue tropism, and antigenic makeup and have the ability to alter the expression of major surface antigenic proteins. although less well studied, strains of m. syn ...19989706080
the subunit b of the f0f1-type atpase of the bacterium mycoplasma pneumoniae is a lipoprotein.the dna sequence analysis of the f0f1-atpase operon of the bacterium mycoplasma pneumoniae predicted that the subunit b, encoded by the gene atpf, is a lipoprotein of the murein lipoprotein type of escherichia coli. here we experimentally verify this prediction by metabolic labeling of subunit b with [14c]palmitic acid and by in vivo interfering with the processing of the prolipoprotein form of subunit b by the antibiotic globomycin, a specific inhibitor of the signal peptidase ii. our results s ...19989733782
susceptibility of avian mycoplasmas isolated in taiwan to 21 antimicrobial agents.twenty-one antimicrobial agents were incorporated individually into frey's agar to evaluate their inhibitory activities against 86 isolates of avian mycoplasmas recently detected in taiwan. among them, 45 and 37 isolates were found positive with mycoplasma gallisepticum and mycoplasma synoviae fluorescent antibody conjugate, respectively. twenty-one other isolates were unable to be identified by the above 2 conjugates. all of the field isolates were highly sensitive (with mic50 < 1 microgram/ml) ...19949747335
a protein (m9) associated with monoclonal antibody-mediated agglutination of mycoplasma gallisepticum is a member of the pmga family.a 62-kda cell surface antigen (m9) of mycoplasma gallisepticum pg31 that mediates antibody-induced agglutination of the organism was purified and subjected to n-terminal amino-acid sequencing. a 999-bp region of the cdna encoding the m9 protein was generated by reverse transcription-pcr, and its nucleotide sequence was determined. pcr primers based on this sequence were used to screen a genomic dna library of pg31. a full-length m9 protein-encoding gene was isolated and sequenced, revealing 96% ...19989784576
expression of the pmga genes of mycoplasma gallisepticum is controlled by variation in the gaa trinucleotide repeat lengths within the 5' noncoding regions.we analyzed the segment of dna which contains the expressed pmga gene from one strain of mycoplasma gallisepticum in normal (strain s6) cells and in cells in which pmga1.1 gene expression had ceased as a consequence of in vitro culture in the presence of pmga1. 1-specific antibodies. sequence analysis of isolates lacking pmga1.1 expression revealed that this gene, which is typically expressed, exhibited sequence changes within a region 5' to its promoter. specifically, pmga1.1(+) cells contained ...19989826362
molecular and biochemical analysis of a 105 kda mycoplasma gallisepticum cytadhesin (gapa).the identification of a gene (gapa) from mycoplasma gallisepticum with homology to the p1 cytadherence gene of mycoplasma pneumoniae is reported. the gapa gene is a 2895 bp orf encoding a protein with a molecular mass of 105 kda. nucleotide sequence analysis of the gapa gene revealed 45% homology to the m. pneumoniae p1 gene, 46% homology to the mycoplasma genitalium mgpa gene and 47% homology to the mycoplasma pirum p1-like protein gene. it has a 64 mol % a+t content compared to 46, 60 and 72 m ...19989846732
safety of a temperature-sensitive clone of mycoplasma synoviae as a live vaccine.a temperature-sensitive (ts+) clone derived from the australian mycoplasma synoviae (ms) field isolate 86079/7ns was produced by chemical mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine and assessed for safety as a live vaccine. this clone, designated ms-h, was assessed for pathogenicity in three different models with air sac lesions as the criterion. no air sac lesions were observed when ms-h was administered to specific-pathogen-free hybrid white leghorn (hwl) chickens by eyedrop at 10 t ...19989876835
in vitro and in vivo comparisons of valnemulin, tiamulin, tylosin, enrofloxacin, and lincomycin/spectinomycin against mycoplasma gallisepticum.the minimum inhibitory concentrations (mics) for valnemulin, tiamulin, enrofloxacin, tylosin, and lincomycin/spectinomycin were determined for a virulent strain of mycoplasma gallispeticum (mg). at the initial reading, the lowest mics were seen with valnemulin and tiamulin, followed by tylosin, enrofloxacin, and a relatively high mic for lincomycin/spectinomycin. at the final reading, at 14 days, a similar pattern was obtained, with valnemulin giving the lowest mic (< 0.008 mg/ml). the same stra ...19989876842
complementary randomly amplified polymorphic dna (rapd) analysis patterns and primer sets to differentiate mycoplasma gallisepticum strains.randomly amplified polymorphic dna (rapd) analysis was used to differentiate 7 strains of mycoplasma gallisepticum. six commercially available primers or primer combinations were screened for their ability to differentiate vaccine and type strains. although major and minor bands were produced with each primer, many of the primers were unsuitable for strain differentiation. the use of primer 6 and combined primers 3 and 4 resulted in complementary rapd banding patterns for each m. gallisepticum s ...199910098688
the characterization of mycoplasma synoviae ef-tu protein and proteins involved in hemadherence and their n-terminal amino acid sequences.an abundant cytoplasmic 43-kda protein from mycoplasma synoviae, a major pathogen from poultry, was identified as elongation factor tu. the n-terminal amino acid sequence (akldfdrskehvnvgtighv) has 90% identity with the sequence of the mycoplasma hominis elongation factor tu protein. monoclonal antibodies reacting with the m. synoviae elongation factor tu protein also reacted with 43-kda proteins from the avian mycoplasma species mycoplasma gallinarum, mycoplasma gallinaceum, mycoplasma pullorum ...199910220885
the effects of f strain mycoplasma gallisepticum, mycoplasma synoviae, and the dual infection in commercial layer hens over a 44-week laying cycle when challenged before beginning of lay. ii. egg size distribution.in each of two trials, 160 commercial pullets were separated into four treatments with four replicates of 10 chickens in each treatment. forty pullets were designated as controls and received no inoculation; 40 pullets received f strain mycoplasma gallisepticum (fmg); an additional 40 pullets received mycoplasma synoviae (ms); and the final 40 pullets were inoculated with both fmg and ms (dual). all inoculations occurred at 10 wk of age. eggs from all treatments were collected daily, monday-thur ...199910396648
mycoplasma synoviae surface protein mspb as a recombinant antigen in an indirect elisa.mycoplasma synoviae is a poultry pathogen causing respiratory disease and synovitis. a number of serological assays have been developed for diagnosis of m. synoviae infection; however, they lack sensitivity and/or are prone to false-positive reactions. using a combination of pcr and expression cloning, four overlapping regions (regions 1-4) of the surface antigen mspb of m. synoviae wvu-1853 were expressed in a bacterial expression system. immunostaining of the resultant polypeptides with chicke ...199910463175
a gene family in mycoplasma imitans closely related to the pmga family of mycoplasma gallisepticum.the avian pathogen mycoplasma gallisepticum possesses a large gene family encoding lipoproteins which function as haemagglutinins. representative species of the pneumoniae phylogenetic group of mycoplasmas were examined for the presence of genes homologous to members of this multigene family. antisera against the pmga1.1 lipoprotein recognized a 35 kda protein in mycoplasma imitans, but did not recognize proteins of mycoplasma genitalium, mycoplasma pneumoniae, mycoplasma pirum, mycoplasma penet ...199910463176
effects of age at inoculation and induced molt on the recovery of mycoplasma gallisepticum from layer chickens.an experiment was conducted to determine the effects of age at inoculation and induced molt on the reisolation of mycoplasma gallisepticum (mg) from commercial leghorn hens that had been eyedrop-inoculated with f strain mg at either 10 or 66 wk of age. chickens were maintained in biological isolation units from 10 wk of age through 78 wk of age. at 70 wk of age (premolt), hens were swabbed, cultured for mg, and molted. swabs were taken both at the end of molt (postmolt [74 wk]) and again 4 wk la ...199910494421
the comparison of an aqueous preparation of tilmicosin with tylosin in the treatment of mycoplasma gallisepticum infection of turkey poults.a virulent strain of mycoplasma gallisepticum (mg) was used to infect groups of 40 2-day-old poults kept in separate pens of 10 each. of the six groups, three were treated with separate concentrations of tilmicosin, one was treated with tylosin, one remained untreated, and a final group was not infected and not treated. mortality, clinical signs, and gross lesions were significantly less (p < 0.001) in the uninfected and infected medicated groups than in the infected unmedicated group. also, the ...199910494422
survey of pathogens and blood parasites in free-living passerines.to determine the disease prevalence of free-living passerines, 1709 passerines were sampled from 38 different field sites in ohio. choanal and cloacal swabs were collected from each bird and cultured for the presence of pasteurella multocida, salmonella spp., and escherichia coli by standard microbiologic techniques. in addition, the serum from each bird was analyzed for the presence of antibodies to mycoplasma gallisepticum, mycoplasma synoviae, newcastle disease virus, and avian influenza viru ...199910494426
field investigation of mycoplasma gallisepticum infections in house finch (carpodacus mexicanus) eggs and nestlings.we conducted a field study to investigate the occurrence of mycoplasma gallisepticum (mg) in eggs and nestlings from nests of house finches (carpodacus mexicanus). forty-three nests were located between the months of april and august 1998 and were followed with one to three sampling efforts. vitelline membrane of fresh eggs, whole embryos, or swabs from the choanal cleft or conjunctiva of nestlings were inoculated into mycoplasma broth for mg isolation and polymerase chain reaction (pcr) testing ...199910494429
pathogenic effects on domestic poultry of a mycoplasma gallisepticum strain isolated from a wild house finch.mycoplasma gallisepticum (mg) has been isolated from wild house finches. the pathogenic effects of mg finch strain (k4058) and mg r-strain were compared after exposure of chickens and turkeys. gross and histologic lesions, reisolation of the organism, serology, and clinical disease were evaluated. milder histologic and gross lesions, in addition to lower serologic titers, occurred in birds inoculated with the finch strain. mortality, concurrent with clinical and gross respiratory signs and lesio ...199910611979
mycoplasma gallisepticum -induced release of macrophage inflammatory protein-1 beta from chicken monocytes-macrophages.chicken monocytes and a macrophage-like cell line were used to determine the presence of macrophage inflammatory protein-1 beta (mip-1 beta). rna was extracted from these cells and subjected to reverse transcription with an anti-sense primer specific for the whole length of the mip-1 beta cdna. after a polymerase chain reaction to amplify the cdna, a 200 bp gene product was detected, which corresponded to the molecular weight of the mip-1 beta. the culture supernate of these cells did not have t ...200010627389
gaa trinucleotide repeat region regulates m9/pmga gene expression in mycoplasma gallisepticum.mycoplasma gallisepticum, the cause of chronic respiratory infections in the avian host, possesses a family of m9/pmga genes encoding an adhesin(s) associated with hemagglutination. nucleotide sequences of m9/pmga gene family members indicate extensive sequence similarity in the promoter regions of both the transcribed and silent genes. the mechanism that regulates m9/pmga gene expression is unknown, but studies have revealed an apparent correlation between gene expression and the number of tand ...200010639457
antibodies to selected disease agents in translocated wild turkeys in california.wild turkeys (meleagris gallopavo) trapped within california (n = 715) or imported into california from other states (n = 381) from 1986 to 1996 were tested for exposure to certain disease agents. prevalence of antibody to mycoplasma gallisepticum, mycoplasma meleagridis, salmonella pullorum, salmonella typhimurium, newcastle disease virus, and avian influenza virus was low (0-4%) for wild turkeys trapped within california. with the exception of antibody prevalence to m. meleagridis of 33%, the ...200010682760
sequence polymorphisms within the pmga genes and pmga antigenic variants in mycoplasma gallisepticum.antigenic variants of mycoplasma gallisepticum major surface lipoprotein, pmga, are encoded by a large gene family. in this study sequence analyses of the pcr-amplified pmga genes showed two types of sequences similar to the pmga1.2 gene in m. gallisepticum strains. they differed in the sequence encoding a proline-rich region (prr) at the n-terminus of the pmga protein. the type a genes had sequences similar to the published pmga1.2 gene sequence of strain s6, whereas the type b genes lacked the ...200010689179
detection of mycoplasma gallisepticum and mycoplasma synoviae antibodies in the sera of indigenous chickens by rapid serum agglutination test at mmopane, gaborone, botswana.the mean flock size was ten chickens per rural farmer. antibodies to mycoplasma gallisepticum and mycoplasma synoviae were detected in 57.88% and 67.33% of the chicken sera respectively.199910689706
a novel mechanism for control of antigenic variation in the haemagglutinin gene family of mycoplasma synoviae.high-frequency phase and antigenic variation of homologous lipoprotein haemagglutinins has been seen in both the major avian mycoplasma pathogens, mycoplasma synoviae and mycoplasma gallisepticum. the expression and, hence, antigenic variation of the pmga gene family (encoding these lipoproteins in m. gallisepticum) is controlled by variation in the length of a trinucleotide repeat motif 5' to the promoter of each gene. however, such a mechanism was not detected in preliminary observations on m. ...200010692167
use of an alkaline phosphatase-labelled probe for the detection of mycoplasma synoviae in chickens.short nucleotides directly labelled to alkaline phosphatase (snap probes) are an interesting alternative to digoxigenin-labelled probes (dig probes), because they reduce the number of steps necessary in dot blots for the detection of dna or amplificate. this study examined the questions whether a snap probe might not only save time, but also increase the sensitivity of another pcr-based dna probe test using a digoxigenin probe. amplificates obtained by multispecies polymerase chain reaction (pcr ...200010780170
density-dependent decline of host abundance resulting from a new infectious disease.although many new diseases have emerged within the past 2 decades [cohen, m. l. (1998) brit. med. bull. 54, 523-532], attributing low numbers of animal hosts to the existence of even a new pathogen is problematic. this is because very rarely does one have data on host abundance before and after the epizootic as well as detailed descriptions of pathogen prevalence [dobson, a. p. & hudson, p. j. (1985) in ecology of infectious diseases in natural populations, eds. grenfell, b. t. & dobson, a. p. ( ...200010792031
mycoplasmal conjunctivitis in songbirds from new york.a field study was conducted to determine the prevalence of conjunctivitis and mycoplasma gallisepticum (mg) infections in house finches (carpodacus mexicanus) and other songbirds common to bird feeders in tompkins county (new york, usa). eight hundred two individuals of 23 species and nine families of birds were captured and given physical examinations during the 14 mo study beginning in february 1998. clinical conjunctivitis (eyelid or conjunctival swelling, erythema, and discharge) was observe ...200010813607
identification and expression of a mycoplasma gallisepticum surface antigen recognized by a monoclonal antibody capable of inhibiting both growth and metabolism.in order to identify antigenic proteins of mycoplasma gallisepticum, monoclonal antibodies (mabs) against virulent m. gallisepticum r strain were produced in mice. mab 35a6 was selected for its abilities to inhibit both growth and metabolism of m. gallisepticum in vitro. the mab recognized a membrane protein with an apparent molecular mass of 120 kda. the corresponding gene, designated the mgc3 gene, was cloned from an m. gallisepticum genomic dna expression library and sequenced. the mgc3 gene ...200010816462
lymphocytic infiltration in the chicken trachea in response to mycoplasma gallisepticum infection.a prominent feature of disease induced by mycoplasma gallisepticum is a lymphoproliferative response in the respiratory tract. although this is also seen in other mycoplasma infections, including mycoplasma pneumoniae, the phenotype of the lymphocytes infiltrating the respiratory tract has not been determined. in this study, the numbers and distribution of lymphocytes in the tracheas of chickens infected with a virulent strain of m. gallisepticum were examined. three groups of chickens were expe ...200010832650
molecular characterization of the mycoplasma gallisepticum pvpa gene which encodes a putative variable cytadhesin protein.a putative cytadhesin-related protein (pvpa) undergoing variation in its expression was identified in the avian pathogen mycoplasma gallisepticum. the pvpa gene was cloned, expressed in escherichia coli, and sequenced. it exhibits 54 and 52% homology with the p30 and p32 cytadhesin proteins of the human pathogens mycoplasma pneumoniae and mycoplasma genitalium, respectively. in addition, 50% homology was found with the mgc2 cytadhesin of m. gallisepticum and 49% homology was found with a stretch ...200010858209
in vitro cell invasion of mycoplasma gallisepticum.the ability of the widespread avian pathogen mycoplasma gallisepticum to invade cultured human epithelial cells (hela-229) and chicken embryo fibroblasts (cef) was investigated by using the gentamicin invasion assay and a double immunofluorescence microscopic technique for accurate localization of cell-associated mycoplasmas. the presence of intracellular mycoplasmas in both cell lines was clearly demonstrated, with organisms entering the eukaryotic cells within 20 min. internalized mycoplasmas ...200010858241
[determination and analysis of the nucleotide sequence of a segment of a mycoplasma gallisepticum strain a5969 chromosome, containing operons s10 and rrn23-5]. 200010867916
immunohistochemical detection of mycoplasma gallisepticum antigens in turkey respiratory tissues.an avidin-biotin-immunoperoxidase diagnostic test was developed to facilitate rapid identification of mycoplasma gallisepticum in respiratory tissues of turkeys. this procedure used polyclonal primary antibodies produced in rabbits. turkeys were inoculated into the infraorbital sinus and trachea with the r strain of m. gallisepticum, mycoplasma synoviae, mycoplasma meleagridis, or frey's media. the outer walls of the infraorbital sinuses, lungs, and tracheas were collected and fixed in either 10 ...200010879921
phenotypic variation of mycoplasma iowae surface antigen.the diseases caused by mycoplasmas are generally chronic and persistent and apparently occur notwithstanding a host immune response. the ability to evade the host immune response is facilitated by phenotypic variation in the mycoplasma surface components. the avian mycoplasmas mycoplasma gallisepticum and mycoplasma synoviae have both been previously described to be able to switch their surface antigens, and recent evidence indicates that m. gallisepticum could switch surface antigens under natu ...200010879924
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