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mycoplasma gallisepticum: influence of cell invasiveness on the outcome of experimental infection in chickens.recently we have shown that a low (r(low)) and a high laboratory passage (r(high)) of the poultry pathogen mycoplasma gallisepticum prototype strain r differ markedly in their capability to invade non-phagocytic eukaryotic cells. in the present study the infection traits of these two mycoplasma passages were compared in an in vivo setting. after aerosol inoculation of chickens, m. gallisepticum was re-isolated from the inner organs of birds infected with r(low), whereas no mycoplasma was recover ...200212423769
gapa and crma coexpression is essential for mycoplasma gallisepticum cytadherence and virulence.it was previously demonstrated that avirulent mycoplasma gallisepticum strain r(high) (passage 164) is lacking three proteins that are expressed in its virulent progenitor, strain r(low) (passage 15). these proteins were identified as the cytadhesin molecule gapa, the putative cytadhesin-related molecule crma, and a component of a high-affinity transporter system, hata. complementation of r(high) with wild-type gapa restored expression in the transformant (gt5) but did not restore the cytadheren ...200212438360
cloning and analysis of the gene for a major surface antigen of mycoplasma gallisepticum.myplasma gallisepticum infects a wide variety of gallineaceous birds including chickens, turkeys, and pheasants. infection occurs both horizontally and vertically. thus, control of the spread of m. gallisepticum to noninfected flocks is difficult. continual monitoring is necessary to identify infected flocks even under the most stringent infectious control practices. monitoring, however, is usually performed by measuring hemagglutination activity (ha) in serum, an insensitive and variable test. ...200212495041
effects of genetic selection for high or low antibody response on resistance to a variety of disease challenges and the relationship of resource allocation.lines of white leghorn chickens were selectively bred for either a high (h) or low (l) antibody response to sheep erythrocytes. the parental lines, hh and ll, and reciprocal crosses, hl (sire line cited first and dam line second) and lh, were compared for their responses to various diseases. high antibody titers were associated with reduced body weight. lines and their crosses were challenged with infectious diseases. the ll line was most resistant to mycobacterium avium, whereas the hh line was ...200212495065
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
the macrophage inflammatory protein-1beta in the supernatants of mycoplasma gallisepticum-infected chicken leukocytes attracts the migration of chicken heterophils and lymphocytes.chicken monocytes, macrophages, heterophils and thrombocytes were infected with mycoplasma gallisepticum, and their supernatants were collected and tested for the presence of chemotactic activities. the supernatants from mg-infected monocytes and macrophages were able to attract the migration of both heterophils and lymphocytes. the chemotactic activity in these supernatants could be abolished by antibodies prepared against the 10 amino acid peptides of the macrophage inflammatory protein (mip)- ...200211687266
poor systemic antibody response after vaccination of commercial broiler breeders with mycoplasma gallisepticum vaccine ts-11 not associated with susceptibility to challenge.a live attenuated mycoplasma gallisepticum vaccine, ts-11, has been used for control of m gallisepticum in several countries. the rapid serum agglutination test is usually used as an indicator of flock response to vaccination; however, in some flocks, the detected response may be weak or absent. we investigated whether the low level, or lack, of systemic antibodies in ts-11-vaccinated flocks is correlated with susceptibility to infection after challenge with a virulent m. gallisepticum strain. b ...200212243526
molecular variability of the adhesin-encoding gene pvpa among mycoplasma gallisepticum strains and its application in diagnosis.mycoplasma gallisepticum is an important pathogen of chickens and turkeys that causes considerable economic losses to the poultry industry worldwide. the reemergence of m. gallisepticum outbreaks among poultry, the increased use of live m. gallisepticum vaccines, and the detection of m. gallisepticum in game and free-flying song birds has strengthened the need for molecular diagnostic and strain differentiation tests. molecular techniques, including restriction fragment length polymorphism of ge ...200111326008
monitoring mycoplasma gallisepticum and mycoplasma synoviae infection in breeder chickens after treatment with enrofloxacin.three experimental strains of breeder chickens were accidentally exposed to mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms), presumably from a newly introduced group of leghorn-type pullets. the experimental strains subsequently became infected and were diagnosed positive for mg and ms by the serum plate agglutination (spa) test and confirmed by the hemagglutination inhibition (hi) test and the polymerase chain reaction (pcr) of tracheal swabs. treatment with 10 mg/kg enrofloxacin via ...200111417841
cases of swollen head syndrome in broiler chickens in greece.from 50 commercial broiler flocks included in a study concerning respiratory disease, signs of swollen head syndrome (shs) were shown in eight. postmortem examination was performed in eight birds showing signs of shs from each flock. the trachea and head from each bird were collected for laboratory investigation. an enzyme-linked immunosorbent assay (elisa) was used for the detection of viral and avian mycoplasma antigens in the trachea, and bacteriologic examinations were performed from the inf ...200111569754
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
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
pmga phenotypic variation in mycoplasma gallisepticum occurs in vivo and is mediated by trinucleotide repeat length variation.chickens were infected with a pathogenic strain of mycoplasma gallisepticum, and the expression of pmga, the major surface protein, was inferred by examination of colonies from ex vivo cells. within 2 days postinfection, 40% of cells had ceased the expression of the original pmga surface protein (pmga1.1), and by day 6, the majority of recovered cells were in this category. the switch in pmga phenotype which had occurred in vivo was reversible, since most colonies produced from ex vivo progenito ...200010992515
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
the effects of ts-11 strain mycoplasma gallisepticum vaccination in commercial layers on egg production and selected egg quality parameters.live mycoplasma gallisepticum (mg) vaccines have been usda approved and licensed for use in commercial layer chickens since 1988; however, egg production and egg quality data exist only for the f strain of mg. information pertinent to the effects of ts-11 mg on egg and eggshell quality parameters, as well as egg size distribution, is lacking. in this study, pullets were inoculated at 10 wk of age with ts-11 strain mg and placed in biological isolation units at 10 birds/unit. hen-day egg producti ...200011007009
serological monitoring on layer farms with specific pathogen-free chickens.to monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (spf) chickens were introduced into two layer farms and reared with laying hens for 12 months. spf chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. as a result, antibodies to eight or ten kinds of pathogens were detected in spf chickens on each farm. antibodies to infectious bronchitis virus (ibv), avian nephritis virus, mycoplasma galli ...200011193353
infection and immunity in broiler chicken breeders vaccinated with a temperature-sensitive mutant of mycoplasma gallisepticum and impact on performance of offspring.a comparison of infection and immunity to mycoplasma gallisepticum (mg) in broiler chicken breeders vaccinated with a temperature-sensitive mutant of mg versus nonvaccinated chickens, and the impact on the performance of their offspring was conducted. infection and immunity in breeders were assessed by culture and enzyme-linked immunoassay, respectively. however, performance in their offspring was assessed by studying mg infection in embryos, occurrence of infection titers to mg in relation to m ...200011194034
morphologic observations on respiratory tracts of chickens after hatchery infectious bronchitis vaccination and formaldehyde fumigation.the histologic changes in the respiratory tracts of chickens were evaluated after hatchery fumigation with 40% formaldehyde vapors and vaccination against infectious bronchitis virus with live attenuated vaccine (massachusetts serotype). one-day-old chickens were housed in four isolation units in controlled environmental conditions, fed and watered ad libitum, and separated into four groups: 1) fumigated and vaccinated birds (fv group); 2) nonfumigated and vaccinated birds (nfv group); 3) fumiga ...200011006997
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
protective effect of two mycoplasma gallisepticum protein fractions affinity purified with monoclonal antibodies.two protein fractions of mycoplasma gallisepticum (mg) were affinity purified with monoclonal antibodies a3 and b3, and tested for protective capacity in chickens. one fraction, designated mgp1, appeared as a doublet of 64 and 62kda bands in sodium dodecyl sulphate-polyacrylamide gel electrophoresis gels, while mgp2 consisted of five polypeptides (64, 56, 47, 45 and 43 kda). the molecular mass, haemagglutination activity and matching amino acid sequence of mgp1 suggest that it is identical to pm ...200019184824
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
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
experiences with multispecies polymerase chain reaction and specific oligonucleotide probes for the detection of mycoplasma gallisepticum and mycoplasma synoviae.amplified fragments of the rdna coding for 16s rrna of mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms) were blotted on nylon membranes, followed by dot-blot detection with two species-specific digoxigenin-(dig)-labeled oligonucleotide probes. the sensitivity and specifity of the tests were determined in titration studies with purified homologous and heterologous dna. with the detection protocol used, the msyv8/31 probe showed 100% specifity for ms, while both mg and the related specie ...199926905489
pathogenicity of mycoplasma imitans in mixed infection with infectious bronchitis virus in chickens.mycoplasma imitans (mim) has been isolated from ducks, geese and partridges, and is closely related to mycoplasma gallisepticum (mg). the pathogenicity of mim for chicks was investigated in single and mixed infections with infectious bronchitis virus (ibv) by giving ibv strain m41 at 1-day-old and mim 2 days later. single infections with ibv or mim were also performed. no clinical signs or gross lesions were seen in chicks infected with mim or uninfected control chicks, but they were seen in the ...199926915378
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
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
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
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
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
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
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
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
antibody response detected by immunoblot in respiratory tract washings of chickens after infection with mycoplasma gallisepticum.two experiments were conducted to test the sensitivity of western blotting for detection of m. gallisepticum antibodies in respiratory washings and sera of infected chickens by mouse monoclonal antibodies to chicken igg, igm and iga. in the first experiment, birds infected at 10 days of age were examined 2 weeks later. in the respiratory washings, iga antibodies reacted with eight polypeptides of m. gallisepticum, while igm and igg reacted with three. in the serum iga antibodies were not detecte ...199818484042
assessment of the efficacy of tilmicosin as a treatment for mycoplasma gallisepticum infections in chickens.this study involved two experiments which examined the efficacy of 'in water' tilmicosin medication for the treatment of experimental mycoplasma gallisepticum (mg) disease. the first experiment investigated tilmicosin concentrations of 50, 100, 200 and 400 mg/l administered for 5 days. in the second experiment, dose levels of 50, 75 and 100 mg/l tilmicosin administered for either 3 or 5 days were investigated. the first experiment suggested that tilmicosin was effective in reducing the incidence ...199818483985
lymphoproliferative responses of specific-pathogen-free chickens to mycoplasma gallisepticum strain pg31.mycoplasma gallisepticum (mg) is one of the aetiologic agents of chronic respiratory disease in chickens and infectious sinusitis in turkeys. we investigated humoral and cellular immune mechanisms following experimental infection with four different strains of mg. peripheral blood leukocytes (pbl) obtained from chickens were examined for proliferation using antigen preparations of whole cell mg as stimuli in vitro. a consistent lymphoproliferative response was observed against the homologous who ...199818483998
a comparison of a commercial pcr-based test to culture methods for detection of mycoplasma gallisepticum and mycoplasma synoviae in concurrently infected chickens.the suitability of commercial pcr-based test kits for the detection of either mycoplasma gallisepticum (mg) or m. synoviae (ms) was compared to detection by culture. the mg and ms kit detected six and five homologous strains respectively in broth cultures and there were no reactions with thirteen het-erologous species including m. imitans, a species phylogenetically closely related to mg. tracheal and lung/air-sac swabs were collected from twenty 17-week-old commercial pullets which were seropos ...199818484270
natural case of salpingitis apparently caused by mycoplasma gallisepticum in chickens.a natural case of salpingitis, apparently caused by mycoplasma gallisepticum (mg), in layer chickens is described. in the flock from which the chickens originated, there was a 3 to 4% drop in egg production per month around 250 days old. the production was reduced 70% at 400 days of age, which was 77% of the predisease level. salpingitis was characterized by marked thickening of the oviductal mucosa due to epithelial hyperplasia and marked lymphoplasmacytic infiltration. colonization of mg on th ...199718483915
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
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
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
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
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
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
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
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
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
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
pathogenicity and cytadherence of mycoplasma imitans in chicken and duck embryo tracheal organ cultures.two strains of the avian organism mycoplasma imitans were examined for pathogenicity and cytadherence in chicken and duck embryo tracheal organ cultures, and a virulent strain of the related pathogen mycoplasma gallisepticum was included for comparison. all consistently cause ciliostasis in tracheal explants from both hosts, and examination of infected tissues by immunofluorescence and transmission electron microscopy demonstrated that m. imitans proliferated on the epithelial surface and adhere ...19968550208
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
detection of mycoplasma gallisepticum antibodiesin the sera of village chickens by the enzyme-linked immunosorbent assay. 19968809982
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
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
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
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
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
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
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
in vivo variation of mycoplasma gallisepticum antigen expression in experimentally infected chickens.the antigen expression profiles of mycoplasma gallisepticum isolates obtained from tracheal swabs of chickens after aerosol-inoculation with m. gallisepticum strain r or clonal variant r/e were examined in western immunoblots. a reference anti-m. gallisepticum chicken antiserum and antisera from individual infected chickens as well as monoclonal antibodies (mabs) specific for surface proteins were used to monitor in vivo antigenic variation. mabs 1e5 and 12d8, recognizing pvpa and p67a, recently ...19957571373
dna diversity among isolates of campylobacter jejuni detected by pcr-based rapd fingerprinting.a pcr-based randomly amplified polymorphic dna method was used to amplify campylobacter jejuni dna using a single oligonucleotide primer derived from either a homologous source or from mycoplasma gallisepticum. the method was able to detect the heterogeneity of amplified dna from human, chicken and turkey sources and can be used as a tool to study the epidemiology of campylobacter jejuni infection.19957571378
studies on the efficacy of combined immunostimulant-antibiotic therapy against experimental mycoplasma gallisepticum infection in chickens.josamycin is an antibiotic known to become selectively concentrated intracellularly and in respiratory organs, the habitate of mycoplasma gallisepticum. the aim of this present work was to evaluate the efficacy of josamycin when given alone or combined with an immunostimulant cornebacterium cutis ultralysate. groups of chickens were given josamycin alone or corynebacterium ultralysate alone or both agents or nothing immediately before induction of mycoplasma gallisepticum infection. birds were s ...19958591743
the effect of route of inoculation on protection by killed vaccines in chickens.the effect of various routes of immunization on protection against challenge by virulent agents was examined in chickens. chickens were immunized intratracheally, intranasally, per os, by crop gavage, and intramuscularly. agents examined were killed haemophilus paragallinarum, mycoplasma gallisepticum, and infectious bursal disease virus. results of immunization by intratracheal administration were equivalent to those produced by parenteral administration. all vaccines effectively induced produc ...19958561734
occurrence of keratoconjunctivitis apparently caused by mycoplasma gallisepticum in layer chickens.natural cases of keratoconjunctivitis, apparently caused by mycoplasma gallisepticum (mg), in layer chickens are described. the disease occurred in a commercial flock consisting of 36,000 pullets (babcock), first appearing around 30 days of age. clinically, affected chickens showed unilateral or bilateral swelling of the facial skin and the eyelids, increased lacrimation, congestion of conjunctival vessels, and respiratory rales. some of the severely affected chickens closed their eyes. the morb ...19957725593
detection of specific antibodies directed against a consistently expressed surface antigen of mycoplasma gallisepticum using a monoclonal blocking enzyme-linked immunosorbent assay.sera from 14 groups of chickens inoculated with different laboratory and field strains of mycoplasma gallisepticum (mg) were used to compare the diagnostic potential of the hemagglutination-inhibition (hi) test and a recently developed monoclonal blocking enzyme-linked immunosorbent assay (elisa). hi was performed with strain a5969, commonly used as hemagglutinating antigen, and it could detect 62.7% of the inoculated chickens as positive. of all sera, 83% proved to be positive when examined wit ...19957794187
the 64 kda lipoprotein of mycoplasma gallisepticum has two distinct epitopes responsible for haemagglutination and growth inhibition.a major mycoplasma gallisepticum polypeptide of 64 kda (p64) was characterized using two distinct monoclonal antibodies (mabs), mab ki produced in our laboratory and mab myg 001 produced by avakian & ley (1993). the p64 antigen was shown to be a lipoprotein in a radioimmunoprecipitation assay using [(3)h] palmitic acid-labelled m. gallisepticum cultures. the two mabs inhibited the growth of m. gallisepticum in liquid medium and reacted to two distinct epitopes on the same p64 antigen in competit ...199518645766
evaluation of two commercial enzyme-linked immunosorbent assay kits for the detection of mycoplasma gallisepticum antibodies.sensitivity and specificity of two commercial mycoplasma gallisepticum (mg) enzyme-linked immunosorbent assay (elisa) kits, rapid slide agglutination (sa) and haemagglutination inhibition (hi) tests were compared using sera from specific pathogen free chickens, turkeys or ducks which had been inoculated with various avian mycoplasmas, bacteria or with a reovirus. results show that sensitivity of sa was superior to elisa and hi tests in the ability to detect antibodies formed in early response to ...199418671097
mycoplasma gallisepticum infection in drug-treated chickens: comparison of diagnosis methods including polymerase chain reaction.ten chickens were inoculated with mycoplasma gallisepticum (mg) and treated with enrofloxacine. on eight different dates post-inoculation (pi), tracheal swab samples were collected for mycoplasma culture or detection by polymerase chain reaction (pcr), and blood samples were analysed by slide-agglutination test (sa) and enzyme-linked immunosorbent assay (elisa). results showed that culture and pcr detected mg from 14/80 or 20/80 samples, respectively. the last culture-positive sample was collect ...19947740859
effect of bentonite incorporated in a feed ration with tilmicosin in the prevention of induced mycoplasma gallisepticum airsacculitis in broiler chickens.a factorial arrangement of tilmicosin and bentonite was evaluated for efficacy in broiler chickens infected with mycoplasma gallisepticum and correlated to tilmicosin recovery in a feed assay method. tilmicosin at 300-500 g/ton prevented development of airsacculitis. the addition of 2% bentonite to the ration caused tilmicosin at 300 g/ton to be ineffective in controlling air-sac lesions, whereas 400 and 500 g/ton were moderately effective. six percent bentonite rendered tilmicosin completely in ...19947832702
diseases and management of backyard chicken flocks in chitungwiza, zimbabwe.to gather information on backyard chicken flocks in chitungwiza, an urban center in zimbabwe, 85 flock owners were interviewed. the mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. mean age at slaughter was 12.4 weeks (range 8-24). none of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. most owners co ...19947832719
mycoplasma gallisepticum strain differentiation by arbitrary primer pcr (rapd) fingerprinting.we demonstrate here that the arbitrary primer polymerase-chain-reaction-based dna fingerprinting method (also termed random amplified polymorphic dna or rapd) can be used to distinguish among strains of the avian pathogen mycoplasma gallisepticum. ten base oligonucleotide primers were used individually to prime dna synthesis from genomic dnas. strain-specific arrays of dna fragments were generated, which allowed us to identify and group isolates. isolates of m. synoviae, m. gallinarum and m. ine ...19947870072
effect of mixed live vaccine (newcastle disease and infectious bronchitis) and mycoplasma gallisepticum on the chicken respiratory tract and on escherichia coli infection.interaction between mixed live vaccine (newcastle disease and infectious bronchitis), mycoplasma gallisepticum (mg) and escherichia coli (ec) was studied in specific-pathogen-free chickens, aged 7 days, inoculated intranasally. in the tracheas of chickens inoculated with vaccine, mg and ec, profuse multiplication of ec occurred together with severe and persisent histological lesions, and some birds died from ec infection. similar though less dramatic effects occurred in birds that received vacci ...19947962725
a surface epitope undergoing high-frequency phase variation is shared by mycoplasma gallisepticum and mycoplasma bovis.we have recently reported that three distinct size- and phase-variable surface lipoproteins (vsps) of the bovine pathogen mycoplasma bovis possess a common epitope recognized by monoclonal antibody 1e5. in the present study, we show that this epitope is also present on a size-variant protein (pvpa) of the avian pathogen mycoplasma gallisepticum. application of monoclonal antibody 1e5 in western immunoblot analysis of triton x-114 phase-fractionated proteins and in colony immunoblots, as well as ...19947523302
expression of mycoplasma gallisepticum f-strain surface epitope.the expression of a mycoplasma gallisepticum (mg) f-strain surface epitope was studied using monoclonal antibody 6f10. different f strain colonies were cloned based on positive or negative expression of the 6f10-recognized epitope. clones selected for the lack of expression of this epitope (negative clones) reverted rapidly to positive expression. on the other hand, negative clones derived from f-strain-vaccinated chickens expressed the 6f10-recognized epitope variably. after in vitro passages, ...19947530442
direct and correlated responses to multitrait, divergent selection for immunocompetence.leghorn lines had been selected for an immunocompetence index based on four traits: antibody production to mycoplasma gallisepticum (mg) and pasteurella multocida (pm) vaccines, reticuloendothelial clearance of colloidal carbon (cca), and cell-mediated, wing web response to phytohemagglutinin (pha). the purpose of this study was to produce replicated lines of chickens with divergent levels of multitrait immunocompetence by index selection. the objectives of analyses of generations 5 to 7 of this ...19948165163
differences in major histocompatibility complex frequencies after multitrait, divergent selection for immunocompetence.white leghorn chickens from lines selected for four immune-response traits (ir lines) were serotyped for b system alloantigens characterizing the haplotypes and genotypes to examine the effect of divergent selection for multitrait immunocompetence on mhc haplotype and genotype frequencies. the selected lines were derived from the ottawa strain 7. the selection index included four immunocompetence traits: antibody production against mycoplasma gallisepticum (mg) and pasteurella multocida, inflamm ...19948165171
analysis and characterization of mycoplasma gallisepticum isolates from pennsylvania.because mycoplasma gallisepticum f strain vaccine can be pathogenic in chickens and is pathogenic in turkeys, we monitored the spread of mg f strain into unvaccinated flocks by screening field and experimental isolates. thirteen mg isolates obtained from various sources in pennsylvania were screened using several techniques capable of differentiating between mg strains. dna restriction enzyme analysis (rea), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) protein profiles, n ...19947832700
mycoplasma gallisepticum infection in chukar partridges, pheasants, and peafowl.mycoplasma gallisepticum infection was diagnosed in a group of chukar partridges, pheasants, and peafowl based on serology and isolation techniques. the farm also had quail, chickens, and ducks. clinical signs in growing birds consisted of foamy eyes, swollen infraorbital sinuses, respiratory distress, and death. breeding birds experienced a severe drop in egg production. histologically, the growing birds exhibited lymphoplasmacytic inflammation of the conjunctiva, sinus, and trachea. the most l ...19947702531
development and evaluation of the polymerase chain reaction method for diagnosis of mycoplasma gallisepticum infection in chickens.a polymerase chain reaction (pcr) method specific for mycoplasma gallisepticum (mg) was evaluated. the pcr method was found to detect as few as two colour changing units (ccu) of mg and did not give false positive reactions with other avian mycoplasmas. in chickens inoculated with either mg or mycoplasma synoviae (ms), the pcr method was found to closely correlate with mg culture reisolation methods in chicken intranasally inoculated with mg. all chickens inoculated with ms tested negative using ...19937511790
inhibition of mycoplasma gallisepticum growth and attachment to chick tracheal rings by antibodies to a 64-kilodalton membrane protein of m. gallisepticum.a mycoplasma gallisepticum (mg) strain r protein of 64 kilodaltons (p64) was partially digested from the surface of the bacterium by trypsin. monospecific polyclonal anti-p64 igg inhibited attachment of mg to chick tracheal rings by as much as 69%. however, trypsin treatment of viable mg cells did not reduce attachment to tracheal rings or hemagglutination titer. anti-p64 igg inhibited growth of mg strain r in broth and on solid media, inhibited the uptake of radiolabeled thymidine, but did not ...19938257360
protective immune response to mycoplasma gallisepticum demonstrated in respiratory-tract washings from m. gallisepticum-infected chickens.chickens inoculated with mycoplasma gallisepticum (mg) produced iga, igm, and igg detectable in washings from the upper respiratory tract (urtw; nasal sinuses and turbinates) and lower respiratory tract (lrtw; trachea, lungs, and air sacs). urtw and lrtw from infected chickens had significant protective effects in a mg-inoculated tracheal-ring-organ-culture system. protective effects in vitro correlated positively with total mg-specific immunoglobulin titer, but not iga titer, as determined by e ...19938257359
a comparative study of mycoplasma gallisepticum vaccines in young chickens.ten-day-old leghorn chickens were vaccinated with the f, ts-11, or 6/85 strain of mycoplasma gallisepticum (mg) via the intraocular route or subcutaneously with mg bacterin and challenged by aerosol with the r strain of mg at 30, 60, or 90 days post-vaccination. respiratory reaction post-vaccination, serological response, persistence of the vaccine strain, and protection against aerosol challenge were compared. in general, the ts-11 and 6/85 strains induced a milder post-vaccination reaction tha ...19938141758
cloning and dna sequence of a 29 kilodalton polypeptide gene of mycoplasma gallisepticum as a possible protective antigen.a lambda gt11 clone, designated m1 and having a 0.8 kilobase (kb) insert, was selected by screening a mycoplasma gallisepticum (m.g.) genomic dna library with antisera against m.g. cells and their membrane proteins. the sequence of a 1.7 kb ecori fragment of genomic dna covering the entire m1 insert revealed a long open reading frame, tm-1, that encoded a polypeptide with a deduced molecular weight of 29 kda. an antiserum raised in chicken against the tm-1 polypeptide, which was produced by reco ...19938212828
monoclonal antibodies to mycoplasma gallisepticum membrane proteins.monoclonal antibodies (mabs) were prepared to study the immunogenesis of mycoplasma gallisepticum. balb/c mice were immunized with m. gallisepticum immunostimulating complexes and the supernatant of heterokaryotes screened with m. gallisepticum and closely related m. synoviae as antigens in indirect enzyme-linked immunosorbent assay. all selected mabs proved to be m. gallisepticum species-specific when they were tested against 10 different avian mycoplasma species. after immunoblotting analysis, ...19938257358
clinical mycoplasma gallisepticum infection in multiplier breeder and meat turkeys caused by f strain: identification by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, restriction endonuclease analysis, and the polymerase chain reaction.in february 1991, a flock of north carolina multiplier breeder turkeys experienced respiratory signs, sinusitis, airsacculitis, and increased mortality. mycoplasma gallisepticum (mg) was isolated, and appropriate control measures were initiated. ultimately, this outbreak involved several breeder flocks of an integrated turkey production company before the last infected flock was identified in may 1991. during this time, mg was also isolated from a flock of commercial layer-type chickens raised a ...19938257382
detection of mycoplasma gallisepticum infection in field samples using a species-specific dna probe.species-specific dna probes for mycoplasma gallisepticum (mg) were compared with serologic and isolation procedures as a routine diagnostic tool on field specimens acquired from chicken flocks experiencing egg-production losses and suspected of mg infection. the mg dna probe clearly identified mg directly from tracheal specimens within 2 days, unlike the 7 to 10 days required for culture procedures. cross-reaction of mg with m. synoviae continues to be a stumbling block in the serum plate agglut ...19938257385
species-specific oligonucleotide probes complementary to 16s rrna of mycoplasma gallisepticum and mycoplasma synoviae.mycoplasma gallisepticum and m synoviae are important avian pathogens causing respiratory diseases which result in great economic losses in poultry farming. two oligonucleotide probes, complementary to the variable region v8 of 16s rrna from the avian mycoplasmas m gallisepticum and m synoviae have, therefore, been designed and used in direct filter hybridisation experiments. both probes gave strong hybridisation signals with their homologous targets, whereas no cross-hybridisations were obtaine ...19938378607
protection against airsacculitis with sequential systemic and local immunization of chickens using killed mycoplasma gallisepticum bacterin with iota carrageenan adjuvant.the induction of protective immunity to mycoplasma gallisepticum (mg) by bacterins containing 0.2% iota carrageenan (icgn) as an adjuvant has been studied. various combinations of intracoelomic (i.c.), intratracheal (i.t.), intranasal (i.n.), intravenous (i.v.), subcutaneous (s.c.) and oral immunization routes were evaluated. vaccinated and non-vaccinated groups were compared with a group vaccinated s.c. with a commercial bacterin. primary i.c. immunization with the bacterin was as effective as ...19938447159
local reaction and serological response in commercial layer chickens injected intramuscularly in the leg with oil-adjuvanted mycoplasma gallisepticum bacterin.the incidence of local vaccine reaction was investigated in three flocks of commercial layer chickens after they were vaccinated intramuscularly in the leg with oil-adjuvanted mycoplasma gallisepticum (mg) bacterin by commercial crews. local vaccine reaction typically involved swelling due to a granulomatous cellulitis in the connective tissue above the tibiotarsal joint of the vaccinated leg. histopathology revealed that the inflammatory reaction was confined primarily to subcutis and muscle fa ...19938141726
the polymerase chain reaction for mycoplasma gallisepticum detection.on the basis of the aligned 16s rrna sequences of mollicutes, a pair of primers was chosen for the detection of mycoplasma gallisepticum. when used in the polymerase chain reaction (pcr), the primers detected a specific amplification of all mg strains tested, yielding an expected 330 bp product. amplification was not detected when other mollicutes or e. coli were used as pcr templates. spf chickens were experimentally inoculated with two strains of m. gallisepticum or mycoplasma iowae. tracheal ...199318671058
indirect elisa for the detection of a specific antibody response against mycoplasma gallisepticum.an indirect enzyme-linked immunosorbent assay (elisa) was developed for determining mycoplasma gallisepticum antibodies in chicken sera. the m. gallisepticum antigen was detergent extracted and incorporated into iscoms. sediment of broth medium treated with sarcosyl was used as control antigen. sera were tested before and after absorption with broth medium components and elisa titres are expressed as optical density (od) at 492 nm. sera from experimentally or naturally infected chickens, those v ...199318671034
evaluation of a monoclonal blocking enzyme-linked immunosorbent assay for the detection of mycoplasma gallisepticum-specific antibodies.a monoclonal blocking enzyme-linked immunosorbent assay (blocking-elisa) was developed to detect antibodies to mycoplasma gallisepticum (mg) in poultry sera with the help of a peroxidase-labeled monoclonal antibody (mab) recognizing an epitope of a 56-kilodalton polypeptide (p56) of mg. immunoglobulins from undiluted mg-positive sera prevent the mab conjugate from attaching to its specific binding site on p56, which results in no color development. the opposite result--a strong color reaction--w ...19937504918
successful treatment of mycoplasmosis in layer chickens with single dose therapy.the efficacy of treatment with single dose administration of 5 drugs at different dosages to layer hens naturally infected with mycoplasma gallisepticum was studied. the drugs were tiamulin, which was administered orally, tylosin (parenterally and orally), spiramycin (orally), long-acting oxytetracycline (parenterally) and tylosindihydrostreptomycin (parenterally). cure was assessed by the absence of nasal discharge. the cure rate was significantly higher (p less than 0.05) in treated hens than ...19921379426
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