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avian mycoplasmosis (mycoplasma gallisepticum).mycoplasma gallisepticum is the most economically significant mycoplasma pathogen of poultry, and has a world-wide distribution. in common with other mycoplasmas, m. gallisepticum is minute in size with minimal genetic information and with a total lack of a bacterial cell wall. these properties are reflected in a high degree of interdependence between m. gallisepticum and the host animal, and in the fastidious nature of the organism in vitro. strains of m. gallisepticum differ markedly with resp ...200010935272
guidelines and recommendations for antimicrobial minimum inhibitory concentration (mic) testing against veterinary mycoplasma species. international research programme on comparative mycoplasmology.the absence of standardised procedures for minimum inhibitory concentration (mic) testing of antimicrobial agents against veterinary mycoplasma and ureaplasma species (mollicutes) has made it difficult to compare results originating from different laboratories. this report, prepared on behalf of the international research programme on comparative mycoplasmology (irpcm), offers guidelines and recommendations for veterinary mic testing of these organisms in an effort to rectify this problem. the s ...200010958240
transposon mutagenesis of mycoplasma gallisepticum by conjugation with enterococcus faecalis and determination of insertion site by direct genomic sequencing.few genetic systems for studying mycoplasmas exist, but transposon tn916 has been shown to transpose into the genomes of some species and can be used as an insertional mutagen. in the current study, the ability of enterococcus faecalis to serve as a donor for the conjugative transfer of transposon tn916 into the genome of the avian pathogen mycoplasma gallisepticum strain pg31 was examined. transconjugants were obtained at a frequency of > or =6 x 10(-8) per recipient cfu. to determine the trans ...200010964629
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
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
analysis of cytadherence-deficient, gapa-negative mycoplasma gallisepticum strain r.comparison of the phenotypic expression of mycoplasma gallisepticum strain r low (passage 15) to that of strain r high (passage 164) revealed that three proteins, i.e., the cytadhesin molecule gapa, a 116-kda protein (p116), and a 45-kda protein (p45), are missing in strain r high. sequence analysis confirmed that the insertion of an adenine 105 bp downstream of the gapa translational start codon resulted in premature termination of translation in r high. a second adenine insertion had also occu ...200011083776
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
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
serologic survey of slaughter-age ostriches (struthio camelus) for antibodies to selected avian pathogens.serum samples from 163 slaughter-age ostriches (struthio camelus) in ohio and indiana were tested for antibodies to avian influenza virus (aiv), newcastle disease virus (ndv), paramyxovirus (pmv) 2, pmv3, pmv7, infectious bursal disease virus (ibdv), bordetella avium, mycoplasma synoviae, mycoplasma gallisepticum, ornithobacterium rhinotracheale, salmonella pullorum, salmonella gallinarum, and salmonella typhimurium. one ostrich had antibodies to aiv h5n9, 57% of the ostriches had antibodies to ...200011195659
host range and dynamics of mycoplasmal conjunctivitis among birds in north america.an epidemic of conjunctivitis among house finches (carpodacus mexicanus) caused by mycoplasma gallisepticum (mg) bacterial infections was first described in 1994. the disease exhibits high primary host specificity, but has been isolated from a limited number of secondary avian hosts at various times and locations. we used records from the house finch disease survey, a continent-wide, volunteer monitoring project, to document the host range of conjunctivitis in birds at feeding stations and to in ...200111272507
characterization of the mycoplasmal conjunctivitis epizootic in a house finch population in the southeastern usa.an epidemiological study of the prevalence of mycoplasmal conjunctivitis in the house finch (carpodacus mexicanus) was conducted in auburn (alabama, usa) between march 1998 and february 1999. clinical disease was observed in 4% of the 1,214 finches trapped and examined. this rate is comparable to the average annual prevalence observed in this population since 1996, although the prevalence of clinical disease observed in the peak months of september through november was lower than in previous yea ...200111272508
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
maintenance of a captive flock of house finches free of infection by mycoplasma gallisepticum.since the beginning of an epidemic of conjunctivitis in wild house finches caused by mycoplasma gallisepticum (mg), all captive colonies established by capturing free-ranging house finches from the eastern population have also either been infected at the time of capture or developed infection shortly after capture. in an attempt to avoid this infection in captive flocks being maintained for studies of the finches' behavior and ecology, we compared two different flock management strategies and we ...200011195652
health status of northern bobwhite quail (colinus virginianus) in eastern kansas.the health status of wild northern bobwhite quail (colinus virginianus) from lyon county, kansas, was evaluated by conducting comprehensive health assessments on 25 birds. gross lesions indicative of avian pox, ulcerative enteritis, and quail bronchitis were not present. serologic tests for antibodies to salmonella pullorum, salmonella gallinarum, pasteurella multocida, mycoplasma gallisepticum, mycoplasma synoviae, and avian adenoviruses were all negative. intestinal coccidia (eimeria spp.) wer ...200011195653
diagnosis and treatment of conjunctivitis in house finches associated with mycoplasmosis in minnesota.an ongoing outbreak of mycoplasma gallisepticum-associated conjunctivitis in house finches (carpodacus mexicanus) that began in 1994 in the eastern united states has been spreading westward. house finches presenting with the clinical signs of m. gallisepticum-associated conjunctivitis were first seen at the wildlife rehabilitation center of minnesota (minnesota, usa) in july of 1996, and 42 cases were admitted from 26 december 1996 to 10 august 1997. a nested pcr was designed for sensitive and s ...200111310874
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
characterization of mycoplasma gallisepticum infection in captive house finches (carpodacus mexicanus) in 1998.since 1995, the epidemic of mycoplasmal conjunctivitis in eastern house finches has affected the auburn, al, house finch population. to better characterize the current status of this host-parasite interaction, we established a captive flock of 38 seronegative, healthy finches in fall 1998. after a minimum quarantine period of 4 wk, two mycoplasma gallisepticum (mg)-infected house finches were introduced into this flock. over a 12-wk period, the flock was captured every 2 wk and each bird was obs ...200111332501
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
gene re-arrangement and fusion in mycoplasma gallisepticum thya-nrdfei locus.sequencing of mycoplasma gallisepticum genome fragment containing thymidylate synthase and ribonucleotide reductase gene clusters reveals both its unusual organization and gene content. sequence analysis indicates the presence of a gene whose product can be considered as a fusion of two full size proteins: the n-terminal part shows significant similarity to mycoplasmal dihydrofolate reductases, while the c-terminal part of the polypeptide chain shows significant similarity to eukaryotic deoxycyt ...200111410345
mycoplasma gallisepticum in house finches (carpodacus mexicanus) and other wild birds associated with poultry production facilities.since 1994, an epidemic of conjunctivitis caused by mycoplasma gallisepticum (mg) has spread throughout the eastern population of house finches (carpodacus mexicanus). the adaptation of mg to a free-flying avian species presents potential problems for the control of mycoplasmosis in commercial poultry. to evaluate risks associated with this emerging problem, a field survey was conducted to assess prevalence of mg infection in house finches and other passerine birds associated with poultry farms. ...200111417811
in vitro susceptibility of avian mycoplasmas to enrofloxacin, sarafloxacin, tylosin, and oxytetracycline.in vitro susceptibility of avian mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms) to enrofloxacin, sarafloxacin, tylosin, and oxytetracycline was determined by a serial broth dilution method. the minimum inhibitory concentration (mic) was recognized by a conversion of the ph indicator phenol red in culture media to a yellow color. each isolate or type strain of mycoplasma was tested in two replicates. the mics of tylosin, enrofloxacin, sarafloxacin, and oxytetracycline against five iso ...200111417828
mycoplasmosis in evening and pine grosbeaks with conjunctivitis in quebec.an outbreak of conjunctivitis affected evening grosbeaks (coccothraustes vespertinus) and pine grosbeaks (pinicola enucleator) in quebec (canada) during the winter 1998-99. one to 30% of the individuals from these two species were sick at 13 feeding stations. sick birds were thin and had unilateral or bilateral catarrhal and lymphoplasmacytic conjunctivitis and rhinitis, and mucopurulent infra-orbital sinusitis. mycoplasmal organisms were isolated in cultures in an affected evening grosbeak and ...200111763749
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
molecular differentiation of mycoplasma gallisepticum and mycoplasma imitans strains by pulsed-field gel electrophoresis and random amplified polymorphic dna.pulsed-field gel electrophoresis (pfge) and random amplified polymorphic dna (rapd) analysis were used to compare 21 mycoplasma gallisepticum strains and five m. imitans strains. each strain of m. gallisepticum typed by pfge and rapd methods was genetically quite unique and rapd and pfge fingerprinting enabled strain characterization. relationships between the m. gallisepticum and m. imitans strains were established and dendrograms were drawn from pfge and rapd patterns. pfge group a and rapd gr ...200111765805
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
characterization of mutations in dna gyrase and topoisomerase iv involved in quinolone resistance of mycoplasma gallisepticum mutants obtained in vitro.mycoplasma gallisepticum enrofloxacin-resistant mutants were generated by stepwise selection in increasing concentrations of enrofloxacin. alterations were found in the quinolone resistance-determining regions of the four target genes encoding dna gyrase and topoisomerase iv from these mutants. this is the first description of such mutations in an animal mycoplasma species.200211796386
biochemical and antigenic characterisation of mycoplasma gallisepticum membrane proteins p52 and p67 (pmga).two membrane proteins from the avian pathogen mycoplasma gallisepticum have been previously purified using a simple, efficient and non-denaturing method: a lipoprotein p67 (pmga) and p52. in the current study, the lipid part of p67 was chemically analysed. the molecular structure of the lipoprotein-lipid component was determined to be s-glyceryl cysteine with two o-ester-linked acyl chains. fatty acid analysis of the purified p67 indicated a heterogeneous composition: palmitic acid (16:0)>steari ...200111797048
trinucleotide gaa repeats dictate pmga gene expression in mycoplasma gallisepticum by affecting spacing between flanking regions.the pmga genes of the avian respiratory pathogen mycoplasma gallisepticum encode a family of hemagglutinins that are subject to phase variation. a trinucleotide gaa repeat region is located upstream of the pmga transcription start site. the length of the repeat region varies at a high frequency due to changes in the number of repeat units. previous studies have shown that pmga genes are transcribed when 12 gaa repeats are present but are not transcribed when the number of repeats is not 12. to f ...200211844762
domain-level differences in microsatellite distribution and content result from different relative rates of insertion and deletion mutations.microsatellites (short tandem polynucleotide repeats) are found throughout eukaryotic genomes at frequencies many orders of magnitude higher than the frequencies predicted to occur by chance. most of these microsatellites appear to have evolved in a generally neutral manner. in contrast, microsatellites are generally absent from bacterial genomes except in locations where they provide adaptive functional variability, and these appear to have evolved under selection. we demonstrate a mutational b ...200211875028
field evaluation of tylosin premix in layers previously vaccinated with a live mycoplasma gallisepticum vaccine.mycoplasma gallisepticum infection results in numerous clinical signs including a reduction in egg production in laying chickens. attempts to prevent mycoplasmosis have included vaccination with both killed and attenuated live m. gallisepticum strains. live vaccines provide reduction in clinical signs and have been shown to replace indigenous strains when used in a consistent program for several placements. antibiotic therapy is another option for controlling losses associated with mycoplasmosis ...200211922337
emerging infectious diseases in wildlife.the processes which give rise to emerging infectious diseases of wildlife can be categorised as follows: ecosystem alterations of anthropogenic or natural origin; movement of pathogens or vectors, via human or natural agency; and changes in microbes or in the recognition of emerging pathogens due to advances in the techniques of epidemiology. these are simplistic divisions because factors influencing the emergence of diseases of wild animals generally fall into more than one category. mycoplasmo ...200211974625
construction of mini-tn4001tet and its use in mycoplasma gallisepticum.the mollicutes are a group of cell-wall-less bacteria and are important plant and animal pathogens. progress toward analyzing their pathogenic mechanisms has been hampered by the few available genetic tools. of the two transposons shown to function in mycoplasmas, only tn4001 is readily amenable to modification and development. one disadvantage of using tn4001 in mycoplasmas has been independent insertion of the insertion sequence, is256, probably as a result of inadequate control of the transpo ...200211982334
mycoplasma gallisepticum rpoa gene cluster.two conservative gene clusters, the s10 ribosomal protein region and one (of the two) set of rrna genes, were split in a genome crossover rearrangement event in mycoplasma gallisepticum. as a result of the rearrangement the major part of the s10 ribosomal protein cluster is located upstream of genes for 23s-5s rrna (rrn23-5), but the genes infa-rpl36-rps13-rpoa-rpl17 are located immediately downstream of the isolated gene for 16s rrna (rrn16). a new ribosomal protein cluster infa-rpl36-rps13-rpo ...200211959450
pathogenesis of avian pneumovirus infection in turkeys.avian pneumovirus (apv) is the cause of a respiratory disease of turkeys characterized by coughing, ocular and nasal discharge, and swelling of the infraorbital sinuses. sixty turkey poults were reared in isolation conditions. at 3 weeks of age, serum samples were collected and determined to be free of antibodies against apv, avian influenza, hemorrhagic enteritis, newcastle disease, mycoplasma gallisepticum, mycoplasma synoviae, mycoplasma meleagridis, ornithobacterium rhinotracheale, and borde ...200212014494
susceptibility of a naïve population of house finches to mycoplasma gallisepticum.since 1994 an epidemic of mycoplasmal conjunctivitis has spread throughout the eastern house finch (carpodacus mexicanus) population leading to a significant decline in this population. the infection has not yet been reported from house finch populations west of the great plains. we hypothesized that the western population, like the eastern population, is susceptible to infection, and we tested this hypothesis by experimentally infecting house finches from missoula, montana (usa) with the house ...200212038126
the effects of 6/85 live mycoplasma gallisepticum vaccine in commercial layer hens over a 43-week laying cycle on egg production, selected egg quality parameters, and egg size distribution when challenged before beginning of lay.in each of two trials, 80 commercial leghorn-type pullets were separated into two treatments with four replicates of 10 chickens in each treatment. forty pullets were designated as controls and received no inoculation, whereas the remaining 40 pullets received the 6/85 vaccine strain of mycoplasma gallisepticum (mg) at 10 wk of age. hen-day egg production, egg weight, eggshell strength, haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded weekly in each ...200212061653
infectious agents associated with respiratory disease in pheasants.in a case-control study of the infectious agents associated with natural outbreaks of respiratory disease in pheasants, 28 batches of birds from sites affected by disease and eight batches of birds from unaffected sites were examined by six veterinary laboratories in england, wales and scotland, and tested for mycoplasmas, other bacteria and viruses. sinusitis was the commonest sign of disease and was associated with mycoplasma gallisepticum as detected by pcr in the trachea (p < 0.05) and conju ...200212054135
detection of antibodies to mycoplasma gallisepticum vaccine ts-11 by an autologous pmga enzyme-linked immunosorbent assay.mycoplasma gallisepticum is a poultry pathogen that causes respiratory disease and loss of egg production worldwide. a live attenuated 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. with the use of specific monoclonal antibodies against m. gallisepticum strain s6 pmga in immunoaffinity purif ...200212061651
the necessity of combining genomic and enzymatic data to infer metabolic function and pathways in the smallest bacteria: amino acid, purine and pyrimidine metabolism in mollicutes.bacteria of the class mollicutes have no cell wall. one species, mycoplasma genitalium is the personification of the simplest form of independent cell-free life. its small genome (580 kbp) is the smallest of any cell. mollicutes have unique metabolic properties, perhaps because of their limited coding space and high mutability. based on 16s rrna analyses the mollicutes mycoplasma gallisepticum is thought to be the most mutable bacteria. enzyme activities found in most bacteria are absent from mo ...200212133816
in vitro development of resistance to enrofloxacin, erythromycin, tylosin, tiamulin and oxytetracycline in mycoplasma gallisepticum, mycoplasma iowae and mycoplasma synoviae.the in vitro emergence of resistance to enrofloxacin, erythromycin, tylosin, tiamulin, and oxytetracycline in three avian mycoplasma species, mycoplasma gallisepticum, mycoplasma synoviae and mycoplasma iowae was studied. mutants were selected stepwise and their mics were determined after 10 passages in subinhibitory concentrations of antibiotic. high-level resistance to erythromycin and tylosin developed within 2-6 passages in the three mycoplasma species. resistance to enrofloxacin developed m ...200212119137
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
prevalence of mycoplasma antibodies in lesser prairie-chicken sera.serologic testing by the serum plate agglutination (spa) procedure was performed to detect the presence of cross-reacting antibodies to mycoplasma meleagridis, mycoplasma synoviae, and mycoplasma gallisepticum in lesser prairie-chickens (tympanuchus pallidicinctus) trapped over a 2-yr period in finney and kearny counties of southwestern kansas. sera examined from birds (n = 50) obtained in march-april 2000 tested positive for m meleagridis, m. synoviae, and m. gallisepticum at levels of 6%, 10%, ...200212243537
development and application of a multiplex polymerase chain reaction for avian respiratory agents.a multiplex polymerase chain reaction (pcr) was developed and optimized to simultaneously detect 6 avian respiratory pathogens. six sets of specific oligonucleotide primers for infectious bronchitis virus (ibv), avian influenza virus (aiv), infectious laryngotracheitis virus (iltv), newcastle disease virus (ndv), mycoplasma gallisepticum (mg), and mycoplasma synoviae (ms) were used respectively in the test. with the use of agarose gel electrophoresis for detection of the pcr-amplified dna produc ...200212243534
effects of an s6 strain of mycoplasma gallisepticum challenge before beginning of lay on various egg characteristics in commercial layers.mycoplasma gallisepticum (mg) is a reproductive/respiratory disease in poultry implicated in suboptimum egg production and decreased hatchability. commercial layer hens raised in a controlled environment were inoculated with the s6 strain of mg at 10 wk of age. egg production and selected egg and egg quality parameters were quantitated over the entire lay cycle for inoculated and control birds. the s6 inoculation had no effect on bird weight, egg production, associated egg quality parameters, or ...200212243522
fluoroquinolone resistance in mycoplasma gallisepticum: dna gyrase as primary target of enrofloxacin and impact of mutations in topoisomerases on resistance level.resistant mutants of mycoplasma gallisepticum were selected in vitro by passaging strains 10 times in increasing concentrations of enrofloxacin. the regions of gyra/gyrb and parc/pare, encoding the quinolone resistance-determining regions (qrdrs) of dna gyrase and dna topoisomerase iv, respectively, of the mutants obtained during different passages were sequenced. several mutations were found in the four fluoroquinolone targets. substitution of ser-83-->arg in gyra and ser-80-->leu or trp in par ...200212356806
serological monitoring of 40 swiss fancy breed poultry flocks.rapid serum agglutination, haemagglutination inhibition and enzyme-linked immunosorbent assays were used to screen swiss fancy breed chicken flocks for antibodies against 12 avian infectious agents. for this purpose, 1,002 blood samples from 40 flocks were collected and tested. ten percent of the samples were positive for salmonella gallinarum-pullorum and 62.5% of the flocks were affected. more than 75% of the flocks had antibodies against mycoplasma gallisepticum/mycoplasma synoviae, infectiou ...200212396360
polymerase chain reaction for detection of mycoplasma gallisepticum in environmental samples.the polymerase chain reaction (pcr) was used to detect mycoplasma gallisepticum in samples collected from the environment of experimentally or naturally infected poultry. culture was also used in the experimental infections. of 160 samples of food, drinking water, feathers, droppings or dust collected during experimental infection, 103 were positive using a m. gallisepticum-specific pcr (mg-pcr) and 68 were positive using a pcr (mycoplasma-pcr) that detects all species of the genera mycoplasma, ...200212396361
occurrence of conjunctivitis, sinusitis and upper region tracheitis in japanese quail (coturnix coturnix japonica), possibly caused by mycoplasma gallisepticum accompanied by cryptosporidium sp. infection.on a farm raising approximately 75,000 japanese quail (coturnix coturnix japonica) for egg production, the diseased quail showed clinical signs of swelling of the head, nasal discharge, increased lacrimation, and decreased egg production. the flock experienced a mortality rate of 5.7% per day. macroscopic observation revealed large, gelatinous masses of caseous exudate in the sinuses, egg peritonitis, and airsacculitis. microscopically, non-purulent or purulent inflammation accompanied by lympho ...200212396337
[in vitro resistance acquisition in mycoplasma gallisepticum against ofloxacin, tylosin and spectinomycin].to clarify a mechanism of acquired resistance of two mycoplasma gallisepticum (mg) strains against ofloxacin (oflx) along with tylosin (ts) and spectinomycin (spcm) as the controls, in vitro resistance acquisition test was carried out for 10 subcultures of each strain with increasing the amount of antimicrobials, and maximum growth allowance concentrations (mac) in 10th and primary subcultures were compared. acquisition of resistance in the strains against oflx was moderate and mac of the 10th s ...200212199113
natural cases and an experimental study of h9n2 avian influenza in commercial broiler chickens of iran.since 1998, an epidemic of avian influenza has occurred in the iranian poultry industry. the agent was pathotyped as non-highly pathogenic and subtyped as an h9n2 avian influenza virus. therefore it did not require eradication. however, frequent incidences of high mortality were observed commonly on broiler farms. no other species of bird were affected. the circulation of the virus and mixed infection with other respiratory pathogens, particularly infectious bronchitis virus and mycoplasma galli ...200212396348
a modified live mycoplasma gallisepticum vaccine to protect chickens from respiratory disease.the aim of this study was to assess the efficacy of a modified live mycoplasma gallisepticum vaccine (gt5) for the protection of chickens against infection and respiratory disease. gt5 was constructed by the reconstitution of the avirulent high passage r (r(high)) strain with the gene encoding the major cytadhesin gapa. gt5 expressed gapa on its surface yet retained the phenotypic characteristics of the parental r(high) strain. birds vaccinated with gt5 were protected upon challenge with the vir ...200212399199
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
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 f-strain mycoplasma gallisepticum inoculation at twelve weeks of age on performance and egg characteristics of commercial egg-laying hens.the effects of f-strain mycoplasma gallisepticum (fmg) inoculation during the pullet period on the subsequent performance and egg characteristics of commercial single combed white leghorn hens were evaluated. in two trials, bw, feed consumption, egg production (ep), egg weight, egg size class, relative eggshell water vapor conductance, and relative percentages of eggshell, yolk and albumen weights were determined through approximately 60 wk of age. in each trial, pullets at 12 wk of age were ran ...200212412912
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
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
effects of f-strain mycoplasma gallisepticum inoculation at twelve weeks of age on digestive and reproductive organ characteristics of commercial egg laying hens.experimental inoculation with the f-strain of mycoplasma gallisepticum (fmg) between 8 and 18 wk of age is known to affect reproductive performance in commercial layers. therefore, two trials were conducted to determine if changes in digestive and reproductive organ characteristics also occur in commercial laying hens infected with fmg at 12 wk of age. in trial 1, liver weight, liver lipid and moisture contents, ovary weight, ovarian follicular hierarchy, and the weights, lengths, and histologie ...200212512582
infectious disease survey of rio grande wild turkeys in the edwards plateau of texas.state wildlife agencies have translocated thousands of wild turkeys (meleagris gallopavo) since the 1930s to reestablish this species. because of threats to the domestic poultry industry and wild birds, screening for selected infectious agents has become routine since the early 1980s. one of the principal sources for rio grande wild turkeys (m. gallopavo intermedia) for translocation purposes was the edwards plateau of texas (usa). unfortunately, turkey abundance has declined in the southern edw ...200212528453
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
transposon mutagenesis of mycoplasma gallisepticum.there are few systems available for studying the genetics of the important avian respiratory pathogen, mycoplasma gallisepticum. these techniques are needed to develop a mechanism to study the molecular pathogenesis of m. gallisepticum. tn916 has the ability to transpose into the m. gallisepticum genome by both transformation and conjugation. in this study, peg-mediated transformation was employed for the transfer of tn916 into m. gallisepticum and create a transposon mutant library. transforman ...200312583999
chemotactic response of lymphocytes in chicken embryos infected with mycoplasma gallisepticum.a prominent feature of mycoplasma gallisepticum (mg) infection is a lymphoproliferative response at the site of infection. in this study, artificial air cells (aacs) were made in eggs containing 16-day old chicken embryos. an mg culture and supernates from mg-infected rp-9 cells, hd-11 cells and monocytes were separately deposited on the membranes of the aac. after incubation for 5 days, the eggs were opened and the aac membranes were collected for histopathological examinations. immunolabelling ...200312531685
haemagglutinins of pathogenic avian mycoplasmas.the pathogenic avian mycoplasmas, mycoplasma gallisepticum, mycoplasma synoviae, mycoplasma meleagridis, mycoplasma iowae and mycoplasma imitans, synthesize haemagglutinins that are immunogenic, variably expressed, surface proteins. the haemagglutinins of m. gallisepticum (pmga), m. synoviae (vlha) and m. imitans are lipoproteins, encoded by related multigene families that appear to have arisen by horizontal gene transfer. m. gallisepticum also has genes encoding cytadhesins in its genome but th ...200212593736
phenotypic switching in mycoplasma gallisepticum hemadsorption is governed by a high-frequency, reversible point mutation.mycoplasma gallisepticum is a flask-shaped organism that commonly induces chronic respiratory disease in chickens and infectious sinusitis in turkeys. phenotypic switching in m. gallisepticum hemadsorption (ha) was found to correlate with phase variation of the gapa cytadhesin concurrently with that of the crma protein, which exhibits cytadhesin-related features and is encoded by a gene located downstream of the gapa gene as part of the same transcription unit. in clones derived from strain r(lo ...200312595441
characterisation of mycoplasma gallisepticum strains involved in respiratory disease in pheasants and peafowl.two cases of mycoplasma gallisepticum infection in different avian species in backyard gamebird operations in slovenia were investigated. in the first case, m gallisepticum was associated with severe respiratory disease with almost 20 per cent mortality in pheasants, whereas the infection was less pathogenic for chickens and turkeys reared at the same site. the m gallisepticum isolates from pheasants had a unique pmga gene sequence containing a repeat of 12 nucleotides, and they contained only s ...200312625537
sensory properties of articular afferents following mycoplasma arthritis in the chicken.the physiological properties of joint capsule mechanical nociceptors of monoarthritic chickens (gallus domesticus) were studied by recording the electrical activity from single c (group iv) and a-delta (group iii) fibres dissected from the parafibular nerve. by injecting live mycoplasma gallisepticum cultures into the ankle joint a typical mycoplasma arthritis was induced which was restricted to a single joint. during the early stage of the disease (7-21 days after infection) there was histopath ...200312644261
homologue of macrophage-activating lipoprotein in mycoplasma gallisepticum is not essential for growth and pathogenicity in tracheal organ cultures.while the genomes of a number of mycoplasma species have been fully determined, there has been limited characterization of which genes are essential. the surface protein (p47) identified by monoclonal antibody b3 is the basis for an enzyme-linked immunosorbent assay for serological detection of mycoplasma gallisepticum infection and appears to be constitutively expressed. its gene was cloned, and the dna sequence was determined. subsequent analysis of the p47 amino acid sequence and searches of ...200312670978
influences of supplemental dietary poultry fat and f-strain mycoplasma gallisepticum infection on the early performance of commercial egg laying hens.f-strain mycoplasma gallisepticum (fmg) may alter reproductive performance in layers through its effects on lipid metabolism. therefore, the influences of 1.5% supplemental dietary poultry fat (pf) and fmg infection on the early performance of commercial egg-laying hens were determined. birds were either sham- or fmg-inoculated at 12 wk, and experimental diets were initiated at 20 wk of age. body weight at 12, 20, and 24 wk, total daily egg mass, feed consumption and feed conversion at 20 and 24 ...200312710479
effects of f-strain mycoplasma gallisepticum inoculation at twelve weeks of age on egg yolk composition in commercial egg laying hens.in two trials, the effects of f-strain mycoplasma gallisepticum (fmg) on the contents of egg yolks from commercial single comb white leghorn laying hens were investigated over a production cycle. ten hens were assigned to each of 8 (trial 1) or 16 (trial 2) negative pressure fiberglass biological isolation units. birds in half of the total units served as sham-inoculated controls, and those in the other half were inoculated with fmg at 12 wk of age. eggs were collected and yolks were harvested a ...200312710476
cytadherence-deficient mutants of mycoplasma gallisepticum generated by transposon mutagenesis.cytadherence-related molecules of mycoplasma gallisepticum strain r-low were identified by tn4001 transposon mutagenesis with the hemadsorption (ha) assay as an indicator for cytadherence. three gm(r) ha-negative (ha(-)) colonies displaying a stable ha(-) phenotype through several successive generations in which gentamicin selection was maintained were isolated from four independent transformation experiments and characterized. southern blot analysis showed that the transposon was inserted as a ...200312819064
mycoplasma gallisepticum-induced alterations in chicken red blood cells.incubation of mycoplasma gallisepticum with washed chicken red blood cells for 1 hr or 5 hr resulted in altered red blood cell surface morphology and perforations of the cells.200312887211
isolation and characterization of a 6/85-like mycoplasma gallisepticum from commercial laying hens.eighty-three-week-old table egg layers with swollen sinuses were presented with a history of increased mortality. serology revealed positive titers to mycoplasma gallisepticum (mg). the birds were part of a flock in which some birds had been vaccinated with 6/85 live mg vaccine at 18 wk of age. tracheal cultures were obtained from both vaccinated and unvaccinated birds within the flock. the cultures were indistinguishable from 6/85 vaccine by both random amplified polymorphic dna analysis and dn ...200312887214
scanning electron microscopic studies of mycoplasma gallisepticum infection in embryonic tracheae.mycoplasma gallisepticum (mg) was used to infect chicken embryos, and scanning electron microscopy was used to examine the morphologic changes in the tracheae. tracheae harvested from embryos infected with mg for 5 days showed extensive deciliation, surface erosion, and inflammatory cell infiltration. embryonic tracheal explants infected with mg for 6 hr showed the same deciliation and surface erosion. the damage to the tracheal surface caused by mg at the embryonic stage might play a role in th ...200312713177
effects of an s6 strain of mycoplasma gallisepticum challenge at onset of lay on digestive and reproductive tract characteristics in commercial layers.mycoplasma gallisepticum (mg), a reproductive/respiratory pathogen in poultry, has been implicated in suboptimum egg production and decreased hatchability. commercial layer hens raised in a controlled environment were inoculated with the s6 strain of mg at 20 wk of age. the s6 inoculation had no effect on bird weight, egg production, digestive tract weight and length, or histopathologic lesion scores, although significant differences were noted in the lengths and weights of various portions of t ...200312713163
diseases of free-ranging chickens in the qwa-qwa district of the northeastern free state province of south africa.a total of 177 free-ranging chickens from 19 qwa-qwa villages were bled from wing veins over a period of 6 months (june-november 2000). serological tests indicated that 5% of chickens tested had been exposed to newcastle disease, 43% to infectious bronchitis and 63% to mycoplasma gallisepticum infection. mcmaster and visser sieve techniques were used to determine helminth and coccidia from pooled fresh faecal samples. helminths isolated in 37% of the villages investigated were heterakis, ascarid ...200312836740
the complete genome sequence of the avian pathogen mycoplasma gallisepticum strain r(low).the complete genome of mycoplasma gallisepticum strain r(low) has been sequenced. the genome is composed of 996,422 bp with an overall g+c content of 31 mol%. it contains 742 putative coding dna sequences (cdss), representing a 91 % coding density. function has been assigned to 469 of the cdss, while 150 encode conserved hypothetical proteins and 123 remain as unique hypothetical proteins. the genome contains two copies of the rrna genes and 33 trna genes. the origin of replication has been loca ...200312949158
effects of f-strain mycoplasma gallisepticum inoculation at twelve weeks of age on the blood characteristics of commercial egg laying hens.in two trials, the effects of an f-strain mycoplasma gallisepticum (fmg) inoculation at 12 wk of age on the blood characteristics of commercial single combed white leghorn laying hens were investigated throughout lay. variables measured in both trials were whole blood hematocrit, plasma protein (pp), and serum cholesterol, triglycerides (st), and calcium. in both trials, hematocrit at 20 wk of age was significantly increased in birds inoculated with fmg. in trial 1, st and pp were significantly ...200312967252
randomly amplified polymorphic dna (rapd) analysis of mycoplasma gallisepticum isolates from turkeys from the central valley of california.randomly amplified polymorphic dna (rapd) analysis was used to investigate the molecular epidemiology of 26 mycoplasma gallisepticum (mg) isolates obtained from turkeys located in the central valley of california. the mg isolates were recovered from 5 different companies and 13 ranches. each company had unique mg strains. no evidence of spread of mg between companies was detected. rapd analysis of mg isolates within a ranch during an outbreak revealed only a single strain involved in each outbre ...199912968753
the in vivo response of mycoplasma gallisepticum to deoxycorticosterone trimethylacetate. 196113731963
an immunological phenomenon in chickens following infection with mycoplasma gallisepticum. 196113774131
irregular variation in cellular nitrogen associated with culture age of mycoplasma gallisepticum. 196314066489
lipid composition and synthesis in the pleuropneumonia-like organism mycoplasma gallisepticum.tourtellotte, mark e. (university of connecticut, storrs), robert g. jensen, george w. gander, and harold j. morowitz. lipid composition and synthesis in the pleuropneumonia-like organism mycoplasma gallisepticum. j. bacteriol. 86:370-379. 1963.-a simple method of extracting lipids from cells of mycoplasma gallisepticum by use of silicic acid columns is described. proteolipids (peptides) extracted with chloroform-methanol (2:1) by other methods were not extracted with the lipid by this method, n ...196314071787
inhibition of the pleuropneumonia-like organism mycoplasma gallisepticum by certain polyene antifungal antibiotics.lampen, j. oliver (rutgers, the state university, new brunswick, n.j.), james w. gill, peter m. arnow, and i. magana-plaza. inhibition of the pleuropneumonia-like organism mycoplasma gallisepticum by certain polyene antifungal antibiotics. j. bacteriol. 86:945-949. 1963.-the growth of mycoplasma gallisepticum, a sterol-requiring pleuropneumonia-like organism (pplo), was inhibited by certain polyene antifungal antibiotics at the following concentrations: filipin, 0.5 mug/ml; amphotericin b, 3 mug ...196314080805
respiratory pathways in the mycoplasma. i. lactate oxidation by mycoplasma gallisepticum.smith, s. l. (cornell university, ithaca, n.y.), p. j. van demark, and j. fabricant. respiratory pathways in the mycoplasma. i. lactate oxidation by mycoplasma gallisepticum. j. bacteriol. 86:893-897. 1963.-resting cells of mycoplasma gallisepticum 293 required the addition of nicotinamide adenine dinucleotide, thiamine pyrophosphate, and flavine mononucleotide for the maximal rate of sodium lactate oxidation. inhibitor studies, as well as spectrophotometric and chemical assays, indicate that th ...196314080798
a comparison of some characteristics of mycoplasma var. mycoides and mycoplasma gallisepticum. 196414103232
studies on the nutrition and growth requirements of mycoplasma gallisepticum. 196414171257
culture and metabolism of mycoplasma gallisepticum.gill, james w. (university of new hampshire, durham). culture and metabolism of mycoplasma gallisepticum. j. bacteriol. 83:213-218. 1962.-mycoplasma gallisepticum a5969, a strong-growing pleuropneumonia-like organism pathogenic for poultry, was found to be intolerant of extremes of temperature and potassium ion concentration. it ferments glucose to the benefit of cell yield, but glycolysis appears not to be essential to growth. anaerobic growth can be maintained if pyruvate is added as a hydroge ...196213898603
colonial growth of mycoplasma gallisepticum observed with the electron microscope.shifrine, moshe (university of california, davis), jack pangborn, and henry e. adler. colonial growth of mycoplasma gallisepticum observed with the electron microscope. j. bacteriol. 83:187-192. 1962.-mycoplasma gallisepticum strain s(6) was grown on collodion film on solid medium. samples were removed every few hours, fixed, washed, shadowed, and observed with the electron microscope. three distinct forms of growth were observed: elementary cells (hexagonally shaped), platycytes, and exoblasts. ...196213911868
gross morphology and ultrastructure of mycoplasma gallisepticum.domermuth, c. h. (statens seruminstitut, copenhagen, denmark), m. nielsen, e. a. freundt, and a. birch-andersen. gross morphology and ultrastructure of mycoplasma gallisepticum. j. bacteriol. 88:1428-1432. 1964.-the ultrastructure and gross morphology of mycoplasma gallisepticum strains ja and w were studied with an electron microscope. intact specimens were grown on parlodion membranes, fixed with formaldehyde, and studied in situ. sectioned specimens were grown on agar and were prepared for st ...196414234802
antigenic relationship between mycoplasma synoviae and mycoplasma gallisepticum. 196514266930
control of experimental mycoplasma gallisepticum infection in young chickens with tylosin and other antibiotics. 196514253997
brain and muscle lesions caused by mycoplasma gallisepticum in turkey poults. 196514266927
comparison of in vitro and in vivo activity of spiramycin and erythromycin against mycoplasma gallisepticum. 196414155349
chicken red blood cell adsorption test for detection of colonies of mycoplasma gallisepticum developed on agar media. 196514284965
serologic, pathologic, and symptomatic aspects of mycoplasmosis of turkeys.adult male turkeys were exposed to mycoplasma gallisepticum isolate 1010 by either intratracheal inoculation, intrasinus inoculation, intranasal inoculation or by contact with inoculated turkeys. the symptomatic, serologic, and pathologic responses to the different types of exposure were compared. tracheitis occurred only in birds exposed intratracheally or by contact, and sinusitis occurred only in birds exposed via the sinuses. antibody titers, determined by hemagglutination-inhibition and tub ...196514300856
comparison of tube agglutination, hemagglutination-inhibition (hi) and antiglobulin titers on serums of chickens and turkeys infected with mycoplasma gallisepticum. 196514340910
response of the turkey to mycoplasma gallisepticum infection. 196514336873
the effects of sodium sulfate in diets containing chlortetracycline hydrochloride on chicks infected with mycoplasma gallisepticum. 196514340720
the effect of social stress on resistance to infection with escherichia coli or mycoplasma gallisepticum. 196514344031
the chemical composition and submicroscopic morphology of mycoplasma gallisepticum, avian pplo 5969. 196214476188
molecular variability of house finch mycoplasma gallisepticum isolates as revealed by sequencing and restriction fragment length polymorphism analysis of the pvpa gene.mycoplasma gallisepticum, a major pathogen of chickens and turkeys, has caused significant declines in house finch (carpodacus mexicanus) populations in the eastern united states since it was first observed in this species in 1994. there is evidence that m. gallisepticum infection is now endemic among eastern house finches, although disease prevalence has declined, suggesting an evolving host-parasite relationship. studies based on randomly amplified polymorphic dna (rapd) have documented the pr ...200314562892
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