Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
mycoplasma gallisepticum produces a histone-like protein that recognizes base mismatches in dna.mycoplasmas are the smallest known microorganisms, with drastically reduced genome sizes. one of the essential biochemical pathways lost in mycoplasmas is methylation-mediated dna repair (mmr), which is responsible for correction of base substitutions, insertions, and deletions in both bacteria and higher organisms. we found that the histone-like protein encoded by the hima/hup_2 gene of mycoplasma gallisepticum (mghu) recognizes typical mmr substrates, in contrast to homologues from other speci ...201121877760
Pathogenicity and immunogenicity of three Mycoplasma gallisepticum isolates in house finches (Carpodacus mexicanus).Mycoplasma gallisepticum (MG) has become a common cause of conjunctivitis in free-living house finches (Carpodacus mexicanus) since its emergence in the early 1990s. To date, temporal and spatial genotypic variation in MG has been documented, but phenotypic variation in pathogenicity and immunogenicity has not been examined. House finches were inoculated with MG isolates Virginia (VA)1994, California (CA)2006, or North Carolina (NC)2006, which were cultured from free-living house finches with co ...201121885217
change in antimicrobial susceptibility of mycoplasma gallisepticum field isolates.this study compares the antimicrobial susceptibility over time between two groups of mycoplasma gallisepticum (mg) isolates from the same geographical area. minimum inhibitory concentration of 13 antimicrobials was determined against two groups of mg isolates from chickens. group 1 strains (n=22) were isolated in 2004-2005 while group 2 strains (n=7) were isolated in 2007-2008. minimum inhibitory concentration 50 for group 1 versus group 2 was 4/4, 0.5/0.5, ôëñ 0.031/ôëñ 64, ôëñ 0.031/2, ôëñ 0.0 ...201121382675
dietary poultry fat, phytase, and 25-hydroxycholecalciferol influence the digestive and reproductive organ characteristics of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.effects of 2 supplemental concentrations of dietary poultry fat (pf) and the combination of pf, phytase (phy), and 25-hydroxycholecalciferol [25(oh)d] on the gross digestive and reproductive organ characteristics of commercial layers inoculated with f-strain mycoplasma gallisepticum (fmg) were investigated in 2 trials. sham and fmg inoculations were administered at 12 wk (before lay) or 22 wk (onset of lay), dietary treatments [basal control diet (bcd); bcd with 0.75% supplemental pf (lpfd); bcd ...201121406365
effects of vaccination with f-strain mycoplasma gallisepticum on egg production and quality parameters of commercial layer hens previously vaccinated with 6/85-strain mycoplasma gallisepticum.this study was conducted to determine the effect of overlaying (revaccinating) f-strain mycoplasma gallisepticum at 22 or 45 wk of age on commercial leghorn hens previously vaccinated with 6/85-strain m. gallisepticum at 10 wk of age. the treatment groups included unvaccinated hens (group 1), hens receiving 6/85-strain m. gallisepticum only (group 2), and hens receiving 6/85-strain m. gallisepticum followed by f-strain m. gallisepticum at either 22 (group 3) or 45 (group 4) wk of age. there was ...201020181866
differentiation of mycoplasma gallisepticum strains using pcr and high-resolution melting curve analysis.mycoplasma gallisepticum (mg) is an economically important pathogen of poultry worldwide, causing chronic respiratory disease in chickens and turkeys. differentiation of mg strains is critical, especially in countries where poultry flocks are vaccinated with live vaccines. in this study, oligonucleotide primers were designed based on a region preceding the trinucleotide repeat of a member of the vlha gene family, and amplicons of 145-352 bp were generated from cultures of 10 different mg strains ...201020035007
influence of supplemental dietary poultry fat on the digestive and reproductive organ characteristics of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.effects of f-strain mycoplasma gallisepticum (fmg) inoculation and 1.5% supplemental dietary poultry fat (pf) on the digestive and reproductive organ characteristics of commercial layers at 58 wk of age were investigated. sham and fmg inoculations were administered at 12 (before lay) and 22 (early in lay) wk of age, and dietary treatments (basal control diets and basal control diets with pf) were initiated at 20 wk of age. supplemental pf increased bw and decreased isthmal length relative to tot ...201020075276
mycoplasma gallisepticum and mycoplasma synoviae express a cysteine protease cysp, which can cleave chicken igg into fab and fc.major poultry pathogens m. gallisepticum and m. synoviae share a gene encoding a putative cysteine protease cysp similar to papain cysteine protease (c1a subfamily). comparison of the cysp gene sequences of 18 m. synoviae and 10 m. gallisepticum strains sequenced in this study showed polymorphisms, including deletions. seven m. synoviae strains, including the type strain wvu 1853, had a 39 bp deletion in the 3' end of the cysp gene. in the same cysp region, all m. gallisepticum strains sh ...201020966088
influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the performance of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.the effects of 2 levels of supplemental dietary poultry fat (pf) and the combination of pf, phytase (phy), and 25-hydroxycholecalciferol (d(3)) on the performance of commercial layers inoculated with f-strain mycoplasma gallisepticum (fmg) were investigated in 2 trials. sham and fmg inoculations were administered at 12 (before lay) and 22 (early in lay) wk and dietary treatments [basal control diet (bcd), bcd with 0.75% supplemental pf, bcd with 1.50% supplemental pf, and bcd with 1.50% suppleme ...201020371842
systematic search for putative new domain families in mycoplasma gallisepticum genome.abstract:201020384986
development of a duplex real-time taqman pcr assay with an internal control for the detection of mycoplasma gallisepticum and mycoplasma synoviae in clinical samples from commercial and backyard poultry.in this study, we report the development and validation of a duplex real-time polymerase chain reaction (pcr) assay with an internal control using taqman-labelled probes for the detection of mycoplasma gallisepticum and mycoplasma synoviae (duplex mgms pcr). the mgms pcr was highly specific with a sensitivity of 7 and 1 colony-forming units/ml for m. gallisepticum and m. synoviae, respectively, using dilution of pure culture that corresponds to 34 and 29 dna copies per reaction. validation of th ...201020390544
a safety assessment of a fowlpox-vectored mycoplasma gallisepticum vaccine in chickens.a recombinant fowlpox virus vaccine expressing key protective mycoplasma gallisepticum antigens could facilitate in the prevention both of fowlpox virus and m. gallisepticum infections. vectormune fp-mg vaccine, a recombinant fowlpox virus expressing both m. gallisepticum 40k and mgc genes, was assessed for its safety in 8-wk-old specific-pathogen-free white leghorn chickens. the vaccine virus was serially passaged 5 times by wing-web inoculation. based on the postinoculation clinical observatio ...201020460677
mutations in 23s rrna gene associated with decreased susceptibility to tiamulin and valnemulin in mycoplasma gallisepticum.mycoplasma gallisepticum is a major etiological agent of chronic respiratory disease (crd) in chickens and sinusitis in turkeys. the pleuromutilin antibiotics tiamulin and valnemulin are currently used in the treatment of m. gallisepticum infection. we studied the in vitro development of pleuromutilin resistance in m. gallisepticum and investigated the molecular mechanisms involved in this process. pleuromutilin-resistant mutants were selected by serial passages of m. gallisepticum strains pg31 ...201020487023
identification of lipoprotein msla as a neoteric virulence factor of mycoplasma gallisepticum.many lipoproteins are expressed on the surfaces of mycoplasmas, and some have been implicated as playing roles in pathogenesis. family 2 lipoproteins of mycoplasma pneumoniae have a conserved "mycoplasma lipoprotein x" central domain and a "mycoplasma lipoprotein 10" c-terminal domain and are differentially expressed in response to environmental conditions. homologues of family 2 lipoproteins are mycoplasma specific and include the lipoprotein of mycoplasma gallisepticum, encoded by the mga0674 ...201020515935
genetic diversity of mycoplasma gallisepticum field isolates using partial sequencing of the pvpa gene fragment in russia.the genetic diversity of the pvpa gene of mycoplasma gallisepticum (mg) samples originating from commercial chickens was investigated. in the present study, we evaluated the genetic variability of 26 field samples of mg detected in commercial chickens and turkeys from 18 regions of russia and compared them to the reference strains of mg available in genbank. genetic variability was evaluated by partial nucleotide sequencing of the pvpa gene, which encodes a putative cytadhesin protein. compariso ...201020608536
construction of mini-tn4001 transposon vector for mycoplasma gallisepticum.the detailed genetic analysis of mycoplasmas has long been hampered by the lack of appropriate tools for genetic manipulation. in this study, the transposon vector, mini-tn4001tetm, was constructed containing the tnp gene, encoding a transposase gene in staphylococcus aureus, two copies of the is256 inverted repeat sequence (inner and outer) and the tetm gene, from the enterococcus faecalis tn916 transposon, conferring resistance to tetracycline. this vector was electro-transformed into mycoplas ...201021046326
a chronicle of serologic response in commercial layer chickens to vaccination with commercial f strain mycoplasma gallisepticum vaccine.vaccination of multi-age layer operations, wherein one million plus commercial layer chickens are housed, has been spurious until the development of a self-propelled, constant-speed spray vaccinator. still, even with its use, live mycoplasma gallisepticum (mg) vaccinations have been questionable in terms of seroconversion. using the vaccinator as a research tool over the past 5 yr, factors have been elucidated which impact seroconversion to one live mg vaccine in particular, the f strain of mg ( ...201020945798
influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the egg characteristics of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.the effects of supplemental dietary poultry fat (pf), phytase (phy), and 25-hydroxycholecalciferol (d3) on the egg characteristics of commercial layers inoculated with f-strain mycoplasma gallisepticum (fmg) were investigated in 2 trials. sham and fmg inoculations were administered at 12 (before lay) and 22 (onset of lay) wk and 4 dietary treatments [basal control diet (bcd); bcd with 0.75% supplemental pf; bcd with 1.50% supplemental pf; bcd with 1.50% supplemental pf, 0.013% phy, and 0.025% d3 ...201020852097
eye surface area and dosage rates for spray vaccination.spray application of mycoplasma gallisepticum (mg) vaccines is a labor- and time-saving means of mass vaccination of layer chickens. recent assessment of spray characteristics of nozzles commonly used to apply mg vaccine in layer chicken operations has shown that the amount of respirable droplets (< 5 microm) is negligible. topical application of vaccine onto the eye surface has been suggested as a route of vaccination, but no estimates of vaccine load delivered via spray application were found ...201021313856
evaluation of mycoplasma inactivation during production of biologics: egg-based viral vaccines as a model.although mycoplasmas are generally considered to be harmless commensals, some mycoplasma species are able to cause infections in pediatric, geriatric, or immunocompromised patients. thus, accidental contamination of biologics with mycoplasmas represents a potential risk for the health of individuals who receive cell-derived biological and pharmaceutical products. to assess the efficiency of inactivation of mycoplasmas by the agents used in the manufacture of egg-derived influenza vaccines, we ca ...201020228111
spatial variation in an avian host community: implications for disease dynamics.because many pathogens can infect multiple host species within a community, disease dynamics in a focal host species can be affected by the composition of the host community. we examine the extent to which spatial variation in species' abundances in an avian host community may contribute to geographically varying prevalence of a recently emerged wildlife pathogen. mycoplasma gallisepticum is a pathogen novel to songbirds that has caused substantial mortality in house finches (carpodacus mexicanu ...201020130959
common garden experiment reveals pathogen isolate but no host genetic diversity effect on the dynamics of an emerging wildlife disease.host genetic diversity can mediate pathogen resistance within and among populations. here we test whether the lower prevalence of mycoplasmal conjunctivitis in native north american house finch populations results from greater resistance to the causative agent, mycoplasma gallisepticum (mg), than introduced, recently-bottlenecked populations that lack genetic diversity. in a common garden experiment, we challenged wild-caught western (native) and eastern (introduced) north american finches with ...201020561136
phytopathogenicity of avian mycoplasma mycoplasma gallisepticum s6: morphologic and ultracytostructural changes in plants infected with the vegetative forms and the viable but nonculturable forms of the bacterium.the data obtained in this study proved that mycoplasma gallisepticum s6 known as avian pathogen had a phytopathogenic potential. the vegetative forms and the viable but nonculturable (vbnc) forms of this mycoplasma could infect the plants via an assemblage of rootlets, invade different tissues, persist there and cause destructive events characteristic to phytomycoplasmoses. in comparison with the vegetative forms, the vbnc forms induced more prominent destructive changes. this phenomenon might b ...201019716689
mycoplasma sturni from a california house finch with conjunctivitis did not cause disease in experimentally infected house finches.mycoplasma gallisepticum conjunctivitis emerged in 1994 as a disease of free-ranging house finches (carpodacus mexicanus) in north america and has also been isolated from other songbirds with conjunctivitis. a key feature for the successful study of natural and experimental disease has been the apparent, very-high correlation between characteristic eye lesions and m. gallisepticum. mycoplasma sturni was originally isolated from an adult european starling (sturnus vulgaris) with bilateral conjunc ...201020688712
comparative genomic analyses of attenuated strains of mycoplasma gallisepticum.mycoplasma gallisepticum is a significant respiratory and reproductive pathogen of domestic poultry. while the complete genomic sequence of the virulent, low-passage m. gallisepticum strain r (r(low)) has been reported, genomic determinants responsible for differences in virulence and host range remain to be completely identified. here, we utilize genome sequencing and microarray-based comparative genomic data to identify these genomic determinants of virulence and to elucidate genomic variabili ...201020123709
proteomic characterization of mycoplasma gallisepticum nanoforming.the goal of this work was to create a model for the long persistence of mycoplasma gallisepticum in depleted medium and under low growth temperature followed by proteomic study of the model. nanoforms and revertants for m. gallisepticum were obtained. proteomic maps were produced for different stages of the formation of nanoforms and revertants. it is shown that proteins responsible for essential cellular processes of glycolysis, translation elongation, and dnak chaperone involved in the stabili ...201021166642
real-time pcr culture and serology for the diagnosis of mycoplasma gallisepticum in chicken breeder flocks.this study aimed to compare a real-time pcr (rpcr) test with improved detection limit to serology and culture for the detection of mycoplasma gallisepticum (mg) infection in chicken breeder flocks. six hundred and forty-six blood and tracheal swab samples belonging to 31 grandparent chicken breeder flocks were tested by rpcr. the detection limit of rpcr was 0.9 pg microl(-1), with pure mg s6 strain dna and 100 colony forming units (cfus) ml(-1), where both pure culture and tracheal swabs were ar ...201020149561
sickness behaviour acting as an evolutionary trap? male house finches preferentially feed near diseased conspecifics.host behaviour towards infectious conspecifics is a crucial yet overlooked component of pathogen dynamics. selection is expected to favour individuals who can recognize and avoid infected conspecifics in order to reduce their own risk of infection. however, evidence is scarce and limited to species employing chemical cues. here, we experimentally examine whether healthy captive house finches (carpodacus mexicanus) preferentially forage near a same-sex, healthy conspecific versus one infected wit ...201020164082
animal behaviour: an ill wind for finches. 201020164914
bi-antigenic immunoassay models based on the recombinant pvpa proteins for mycoplasma gallisepticum diagnosis in chickens.the present study aimed to produce the relatively conserved central fragment of the mycoplasma gallisepticum pvpa cytadhesin as recombinant antigen and to determine its species-specific diagnostic potential in comparison with the full-length recombinant rpvpa336 protein. for this purpose, a recombinant protein (rpvpa134) consisting of 134 amino acids with apparent molecular mass of 27 kd was produced and highly purified. the rpvpa134 protein was composed of the amino acid residues at positions 1 ...201021088174
[adaptation of mycoplasmas to stressful factors: nucleotide sequences nonregistered in vegetative forms of m. galisepticum s6 cells are revealed in nonculturable forms of the mycoplasma].adaptation of m. gallisepticum s6 to unfavorable environmental conditions is connected with transformation of the vegetative forms of the mycoplasma cells to the viable but non-culturable (vbnc) forms. the vegetative forms and the vbnc forms differ in the spectrum of the pcr-products that was forming due to amplification of the nucleotide sequence of the pvpa-gene coding the able cytoadhesion protein. as to vegetative forms of the mycoplasma the only amplicon, containing one open reading frame ( ...200919807027
influence of supplemental dietary poultry fat on the yolk characteristics of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.effects of f-strain mycoplasma gallisepticum (fmg) inoculation and 1.5% supplemental dietary poultry fat (pf) on the egg yolk characteristics of commercial layers at 24, 34, 44, 50, and 58 wk of age were investigated. sham and fmg inoculations were administered at 12 and 22 wk of age and dietary treatments (basal control and basal control with 1.5% supplemental pf) were initiated at 20 wk of age. yolk lipid concentration was reduced on wk 24 in birds that had been inoculated at 12 or 22 wk of ag ...200919687273
secreted sialidase activity of canine mycoplasmas.through a survey of the phylogenetic distribution of sialidase among mycoplasmas, we detected activity secreted by the type strains of 3 of 11 species frequently or first isolated from dogs. the specific activity of washed cells of the type strains of mycoplasma canis, mycoplasma cynos, and mycoplasma molare ranged from 5.2+/-0.8 x 10(-6) to 1.1+/-0.3 x 10(-5) enzymatic units per colony-forming unit (u/cfu). cells of m. molare strain h542(t) had twice the specific activity (p<0.05) of m. canis s ...200919201110
effects of 6/85-strain mycoplasma gallisepticum vaccination alone at ten weeks of age or in conjunction with f-strain mycoplasma gallisepticum inoculation overlays at twenty-two or forty-five weeks of age on the reproductive and digestive organs of commercial egg-laying hens.two trials were conducted to determine the effects of a prelay 6/85-strain mycoplasma gallisepticum (6/85mg) vaccination alone or in conjunction with time-specific f-strain m. gallisepticum (fmg) inoculation overlays on the gross reproductive and digestive organ characteristics of commercial egg-laying hens. in each trial, the following 4 treatments were applied: 1) sham vaccination at 10 wk of age; 2) vaccination of 6/85mg at 10 wk; 3) 6/85mg at 10 wk overlaid by fmg inoculation at 22 wk; and 4 ...200919211526
proteome of the bacterium mycoplasma gallisepticum.using modern proteomic assays, we have identified the products of gene expression and posttranslational modifications of proteins of the bacterium mycoplasma gallisepticum s6. combinations of different technologies of protein separation by electrophoresis and mass-spectrometric analysis gave us a total of 446 proteins, i.e. 61% of the annotated proteins of this microorganism. the pro-q diamond and pro-q emerald dye technology was used for fluorescent detection of ten phosphoproteins and two glyc ...200919267672
mycoplasma synoviae invades non-phagocytic chicken cells in vitro.mycoplasma synoviae and mycoplasma gallisepticum are major poultry pathogens, but their strains differ significantly in invasiveness and pathogenicity. recent studies have demonstrated that m. gallisepticum invades chicken erythrocytes (cer) and chicken embryonic fibroblasts. the aim of this study was to determine whether m. synoviae also invades chicken cells. using the gentamicin invasion assay, relative invasion frequency (rif) of four m. synoviae strains was determined for cer, chicken embry ...200919321273
development of a real-time polymerase chain reaction assay for the simultaneous detection of mycoplasma gallisepticum and mycoplasma synoviae under industry conditions.in this research we developed a real-time sybr green assay to detect both mycoplasma gallisepticum (mg) and mycoplasma synoviae (ms) in a single reaction. a total of 30,000 samples from broiler breeder flocks were screened using traditional serology (plate agglutination, enzyme-linked immunosorbent assay, hemagglutination inhibition) and polymerase chain reaction (pcr; traditional and real-time). it was determined that the real-time sybr green pcr assay developed in this research was more rapid ...200919432006
the development of diagnostic real-time taqman pcrs for the four pathogenic avian mycoplasmas.four avian mycoplasmas are commonly recognized as poultry pathogens: mycoplasma gallisepticum (mg), mycoplasma synoviae (ms), mycoplasma meleagridis (mm), and mycoplasma iowae (mi). the avian mycoplasmas are associated with respiratory disease, synovitis and arthritis, poor performance, skeletal deformities, and embryo mortality. three main approaches are used for the diagnosis of avian mycoplasmosis: isolation and identification, detection of antibodies, and molecular detection of the organism' ...200919432011
molecular variability of dr-1 and dr-2 within the pvpa gene in mycoplasma gallisepticum isolates.a total of 15 mycoplasma gallisepticum (mg) isolates from chinese poultry farms and three reference strains (s6, bg44t, and f36) were characterized by nested polymerase chain reaction and sequence analysis for two identical and directly repeated sequences, dr-1 and dr-2, within the putative cytadhesin pvpa gene. the molecular variation patterns of the pvpa genes among the 15 mg isolates were identical to the reference strains s6 and bg44t, that is, a 60 bp deletion in dr-1 and dr-2 and repetitio ...200919432015
mycoplasma gallisepticum: an emerging challenge to the poultry industry in egypt.in this study, the authors examined the technical performance of culture methodology using specific media: mycoplasma isolation media of pleuropneumonia-like organisms (pplo) broth and pplo agar. digitonin sensitivity, growth inhibition, the serum plate agglutination test, a commercially available enzyme-linked immunosorbent assay (elisa) and a commercially available simplex polymerase chain reaction (pcr) test were used to detect mycoplasma gallisepticum infections in samples collected from the ...200920462158
[prevalence of mycoplasmas in commercial layer flocks during laying period].within this study's range, laying hens from different housing systems were investigated on prevalence of mycoplasma sp. for the duration of one laying period, with an emphasis on the two clinically relevant species m. synoviae and m. gallisepticum. tracheal swabs were analysed for mycoplasms by genus- and species-specific amplification after dna extraction. of 919 collected tracheal swabs, 84% were positive for the genus-specific test, while 75% turned out positive for m. synoviae. mycoplasms we ...200919517932
influence of supplemental dietary poultry fat on the performance of commercial layers inoculated before or at the onset of lay with f-strain mycoplasma gallisepticum.the effects of f-strain mycoplasma gallisepticum (fmg) inoculation and 1.5% supplemental dietary poultry fat (pf) on the performance of commercial layers between 20 and 58 wk of age were investigated. sham and fmg inoculations were administered at 12 (before lay) and 22 (early in lay) wk and dietary treatments (basal control diets and basal control diets with 1.5% supplemental pf) were initiated at 20 wk of age. mortality at wk 47 and 53 was greatest in birds inoculated with fmg at 22 wk. feed c ...200919531705
production of house finch (carpodacus mexicanus) iga specific anti-sera and its application in immunohistochemistry and in elisa for detection of mycoplasma gallisepticum-specific iga.the iga antibody response plays a vital role in mucosal immunity because it functions to neutralize pathogens at the mucosal surface and thus impedes attachment to underlying tissues. although the importance of iga in the mucosal immunity of galliform birds has been established, studies examining iga-based immunity in passerine birds are lacking, perhaps due in part to the absence of reagents that can detect passerine iga. a 469 base pair region of the house finch (carpodacus mexicanus) iga heav ...200919581004
effect of dosage and vaccination route on transmission of a live attenuated mycoplasma gallisepticum vaccine: a broiler model.mycoplasma gallisepticum (mg) is an economically significant pathogen of poultry species. among the table egg sector of the poultry industry, live attenuated strains of mg are commonly used to limit production losses associated with mg-induced disease. these vaccines, however, may be problematic to broiler- and turkey-related industries because of associated virulence; therefore, an understanding of the transmissibility of the live mg vaccines is of particular importance. in the present study, a ...200919848082
adaptation of mycoplasmas to adverse environments: phytopathogenicity and peculiarities of protein expression of vegetative and nonculturable forms of mycoplasma gallisepticum s6 cells. 200920848917
effects of time-specific f-strain mycoplasma gallisepticum inoculation overlays on prelay ts-11-strain m. gallisepticum vaccination on blood characteristics of commercial laying hens.two trials were conducted to determine the effects of a prelay ts-11-strain mycoplasma gallisepticum (ts-11mg) vaccination alone or in combination with subsequent time-specific f-strain m. gallisepticum (fmg) inoculations on the blood characteristics of commercial laying hens. the following 4 treatments were utilized: 1) sham vaccination at 10 wk of age, 2) vaccination of ts-11mg at 10 wk, 3) ts-11mg at 10 wk overlaid by fmg inoculation at 22 wk, and 4) ts-11mg at 10 wk overlaid by fmg at 45 wk. ...200919359676
effects of time-specific f-strain mycoplasma gallisepticum inoculation overlays on prelay ts-11-strain m. gallisepticum vaccination on digestive and reproductive organ characteristics of commercial egg-laying hens.two trials were conducted to determine the effects of a prelay ts-11-strain mycoplasma gallisepticum (ts-11mg) vaccination alone or in conjunction with f-strain m. gallisepticum (fmg) inoculation overlays at 2 different age periods during lay on the digestive and reproductive organ characteristics of commercial egg-laying hens. in each trial, the following 4 treatments were utilized: sham vaccination at 10 wk of age, ts-11mg vaccination at 10 wk of age, ts-11mg at 10 wk of age overlaid by fmg in ...200919359686
characteristics of a very virulent infectious bursal disease virus from california.an outbreak of infectious bursal disease (ibd) in two california layer flocks resulted in the isolation of two infectious bursal disease viruses designated ra and rb. increased mortality plus gross and histopathology in the layer flocks suggested ra and rb could be very virulent infectious bursal disease virus (vvibdv). preliminary studies indicated that high mortality resulted when bursa homogenates from the layer farms were used to inoculate specific-pathogen-free (spf) chicks. in addition, ra ...200920095162
cytoskeletal asymmetrical dumbbell structure of a gliding mycoplasma, mycoplasma gallisepticum, revealed by negative-staining electron microscopy.several mycoplasma species feature a membrane protrusion at a cell pole, and unknown mechanisms provide gliding motility in the direction of the pole defined by the protrusion. mycoplasma gallisepticum, an avian pathogen, is known to form a membrane protrusion composed of bleb and infrableb and to glide. here, we analyzed the gliding motility of m. gallisepticum cells in detail. they glided in the direction of the bleb at an average speed of 0.4 microm/s and remained attached around the bleb to ...200919286806
diversifying and stabilizing selection of sialidase and n-acetylneuraminate catabolism in mycoplasma synoviae.sialidase activity varies widely among strains and tends to correlate with strain virulence in the avian pathogen mycoplasma synoviae. to characterize the forms of selection acting on enzymes required for sialic acid scavenging and catabolism, the ratios of nonsynonymous (k(a)) to synonymous (k(s)) mutation frequency were calculated for codons in the sialidase gene of 16 strains of m. synoviae and for its nearly identical homolog in four strains of mycoplasma gallisepticum. the k(a)/k(s) (omega) ...200919329630
diseases of backyard turkeys in the mexican tropics.with the purpose of identifying the causes of disease and death in backyard turkeys, 768 interviews with growers were carried out in communities of the coastal region of oaxaca, mexico. later, a clinical sanitary evaluation was performed on five randomly selected turkeys of different age and sex. the laboratory tests included: necropsy for clinical diagnosis of diseases and for a histopathological examination of tissues with macroscopic lesions to identify microscopic lesions; hemagglutination i ...200819120252
[adaptation of mycoplasma gallisepticum to unfavorable growth conditions: changes in morphological and physiological characteristics].adaptation of mycoplasma gallisepticum to unfavorable growth conditions results in altered morphological and physiological characteristics of the cells. m. gallisepticum populations in a complete nutrient medium contain pear-shaped vegetative cells (d approximately 0.3 microm; l approximately 0.8 microm) with pronounced polar and cytoskeleton-like structures. such mycoplasma cells are able to induce damage in a bacterial genome, causing an sos response of the test strain (escherichia coli pq37). ...200819137716
backyard chicken flocks pose a disease risk for neotropic birds in costa rica.pathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the united states, as well as potential economic losses for resource-poor farmers. free-roaming backyard chickens are commonly kept in shade-grown coffee plantations, habitats that attract large numbers of wild birds. the husbandry and pathogen prevalence of backyard chicken flocks in san luis, costa rica, were investigated. based on serologic evidence, newcastle disease virus, infectious laryngo ...200819166045
molecular characterization and typing of enrofloxacin-resistant clinical isolates of mycoplasma gallisepticum.emergence of resistance to fluoroquinolones is mainly due to chromosomal mutations in genes encoding the subunits of the drug's target enzymes, dna gyrase and topoisomerase iv, which are essential for dna replication. the quinolone resistance-determining regions (qrdrs) of these genes were characterized in 25 mycoplasma gallisepticum strains isolated from commercial poultry flocks during 1997-2007, which exhibited different levels of susceptibility to fluoroquinolones. all enrofloxacin-resistant ...200819166064
pure: a webserver for the prediction of domains in unassigned regions in proteins.protein domains are the structural and functional units of proteins. the ability to parse proteins into different domains is important for effective classification, understanding of protein structure, function, and evolution and is hence biologically relevant. several computational methods are available to identify domains in the sequence. domain finding algorithms often employ stringent thresholds to recognize sequence domains. identification of additional domains can be tedious involving inten ...200818554415
development and immunogenicity of recombinant mycoplasma gallisepticum vaccine strain ts-11 expressing chicken ifn-gamma.mycoplasma gallisepticum (mg) is a poultry pathogen that causes respiratory disease and loss of egg production worldwide. a live attenuated vaccine, ts-11, has been used for the control of mg in several countries. to improve the functionality of the vaccine and investigate its potential as a delivery vector for host immune molecules and foreign antigens, we have developed ts-11 as a vector to express and secrete chicken ifn-gamma (ts-11 c3) using a transposon-based delivery vector. following adm ...200818706959
development of a replicable oric plasmid for mycoplasma gallisepticum and mycoplasma imitans, and gene disruption through homologous recombination in m. gallisepticum.the genome of mycoplasma gallisepticum strain r(low) has been sequenced completely, but subsequent genetic studies have been limited by the lack of a replicable vector system. in this study, replicable plasmids were constructed for m. gallisepticum and mycoplasma imitans using the oric region upstream from the soj gene. the oric plasmids of m. gallisepticum (pgtlori) and m. imitans (pmiori) replicated in both species, but mycoplasma pneumoniae could not support replication of pgtlori. a 180 bp s ...200818757791
field evaluation of maternal antibody transfer to a group of pathogens in meat-type chickens.this study was conducted to evaluate the rate of antibody transfer on a flock basis from hens to their day-old chicks in meat-type chickens raised in a commercial setting. fifteen randomly selected hens from a commercial broiler-breeder flock were bled at 37, 40, and 45 wk of age. at day of bleeding, the collected eggs were identified and tracked through hatching where 30 hatchlings were randomly sampled and bled from the jugular vein. antibodies against 10 different pathogens were quantified fr ...200818648048
compatibility of a combination of tiamulin plus chlortetracycline with salinomycin in feed during a long-term co-administration in broilers.the pleuromutilin antibiotic tiamulin (tia) is known to produce a negative interaction in broilers when administered in combination with several ionophore anticoccidials such as salinomycin (sal). chlortetracycline (ctc), when administered simultaneously with tia, has demonstrated a synergistic antimicrobial effect. a 35-d feeding study was conducted in cages to evaluate the interaction effect of a combination of tia plus ctc at increasing inclusion levels when administered concurrently with sal ...200818648050
comparative infectiousness of three passerine bird species after experimental inoculation with mycoplasma gallisepticum.mycoplasma gallisepticum has been isolated from various species of free-living birds, and we therefore tested the hypothesis that bird species other than the main host, the house finch (carpodacus mexicanus), could play a role in the epidemiology of the infection. we compared the disease course in the house finch, american goldfinch (carduelis tristis) and house sparrow (passer domesticus) after inoculation into the conjunctival sac with m. gallisepticum, and also the degree to which the three s ...200819023761
strain differentiating real-time pcr for mycoplasma gallisepticum live vaccine evaluation studies.mycoplasma gallisepticum causes respiratory disease and production losses in poultry. vaccination of poultry with m. gallisepticum live vaccines is an approach to reduce susceptibility to infection and to prevent the economic losses. the development and evaluation of live vaccines usually requires the involvement of several vaccine and challenge strains in the same experimental setup. our goal was to develop a tool to allow the differentiation between a set of known m. gallisepticum strains in a ...200818160233
structural and functional characterization of an organic hydroperoxide resistance protein from mycoplasma gallisepticum.as obligate parasites, mycoplasma species are continuously exposed to oxidative damage due to host-generated peroxides and reactive oxygen species (ros). in addition, the production of endogenous oxidants is believed to be a primary virulence mechanism of several mollicute species, indicating that oxidative stress resistance is crucial to survival of these bacteria in the host milieu. despite the abundance of oxidants at the site of infection, enzymes responsible for the detoxification of ros ha ...200818192392
displaying the protein of mycoplasma gallisepticum agglutinin on the cell surface of bacillus thuringiensis with the s-layer protein.the s-layer protein ctc surface-display system of bacillus thuringiensis (bt) was used to test the possibility of displaying the protein of mycoplasma gallisepticum (mg) agglutinin (pmga) on the bt cell surface. by fusing part of pmga1.2 (pmga1.2p) with the surface-anchoring motif of ctc, two recombinant plasmids, pctc-pmga1.2p and pcspmga1.2p, were constructed. they harboured the fusion genes ctc-pmga1.2p and csa-ctc-pmga1.2p (csa represents csaab operon, important in anchoring the s-layer prot ...200818243589
detection and quantification of mycoplasma gallisepticum genome load in conjunctival samples of experimentally infected house finches (carpodacus mexicanus) using real-time polymerase chain reaction.a taqman-based real-time, quantitative polymerase chain reaction (qpcr) assay utilizing the mgc2 gene was developed to detect mycoplasma gallisepticum in conjunctival swabs of experimentally infected house finches. the assay was demonstrated to be quantitative by the standard curve method with reproducible results within runs and between runs. the detection limit of the mgc2 assay was examined using two standards. the test had a detection limit of less than 14 copies per reaction when tested wit ...200818622854
molecular survey of avian respiratory pathogens in commercial broiler chicken flocks with respiratory diseases in jordan.acute respiratory tract infections are of paramount importance in the poultry industry. avian influenza virus (aiv), infectious bronchitis virus (ibv), newcastle disease virus (ndv), avian pneumovirus (apv), and mycoplasma gallisepticum (mg) have been recognized as the most important pathogens in poultry. in this study, trachea swabs from 115 commercial broiler chicken flocks that suffered from respiratory disease were tested for aiv subtype h9n2, ibv, ndv, and apv by using reverse transcription ...200818281569
effects of 6/85-strain mycoplasma gallisepticum inoculation alone at ten weeks of age or in conjunction with f-strain mycoplasma gallisepticum inoculation overlays at twenty-two or forty-five weeks of age on the performance of commercial egg-laying hens.the effects of 6/85-strain mycoplasma gallisepticum (6/85mg) inoculation alone or in conjunction with a f-strain m. gallisepticum (fmg) overlay and its timing on the performance of commercial egg-laying hens were investigated. control birds received sham inoculations at 10 wk of age. a second treated group of birds was inoculated with 6/85mg at 10 wk of age, a third treatment group of birds was inoculated with 6/85mg at 10 wk and received an overlay of fmg at 22 wk, and a fourth treatment group ...200818281589
a recombinant antigen-based elisa for the simultaneous differential serodiagnosis of mycoplasma gallisepticum, mycoplasma synoviae, and mycoplasma meleagridis infections.we have previously identified species-specific dna fragments, referred to as ms2/28 and mm14, of mycoplasma synoviae and mycoplasma meleagridis, respectively. in the present study, we extended our analysis of the ms2/28 fragment that was found to encode a species-specific antigenic site, and we demonstrated the specificity of the mycoplasma gallisepticum hemagglutinin protein encoded by pmga1.2 (a member of the vlha gene family). then, we combined the escherichia coli-expressed products of ms2/2 ...200818646449
effects of supplemental dietary phytase and 25-hydroxycholecalciferol on the performance characteristics of commercial layers inoculated before or at the onset of lay with the f-strain of mycoplasma gallisepticum.the effects of dietary supplementation with phytase and 25-hydroxycholecalciferol on the performance characteristics of commercial layers that were inoculated prelay (12 wk of age) or at the onset of lay (22 wk of age) with f-strain mycoplasma gallisepticum were assessed. experimental layer diets, which included a basal control diet or the same diet supplemented with 0.025% phytase and 25-hydroxycholecalciferol, were fed from 20 through 58 wk of age. weekly and total egg production were determin ...200818281591
identification of major immunogenic proteins of mycoplasma synoviae isolates.mycoplasma synoviae isolates differ in patterns of immunogenic proteins, but most of them have not been identified yet. the main aim of this study was their identification in two closely related m. synoviae isolates, ulb 02/p4 and ulb 02/ov6, recovered recently from chickens in slovenia. n-terminal sequencing identified 17 m. synoviae proteins. amongst them were 14 major, highly expressed but previously unidentified proteins, including enzymes, chaperones and putative lipoproteins. ulb 02/p4 pro ...200817720337
effects of a prelay 6/85-strain mycoplasma gallisepticum inoculation alone or in conjunction with subsequent f-strain m. gallisepticum inoculations during lay on the internal egg characteristics of commercial egg-laying hens.the effects of a prelay 6/85-strain mycoplasma gallisepticum (6/85 mg) inoculation alone or in conjunction with subsequent f-strain m. gallisepticum (fmg) inoculations during lay on the internal egg characteristics of commercial egg-laying hens were investigated. in the first 2 treatment groups, birds were sham inoculated or were inoculated with 6/85 mg at 10 wk of age. in a third treatment group, birds were inoculated with 6/85 mg at 10 wk in conjunction with a subsequent inoculation of fmg at ...200818493000
in vitro susceptibilities to fluoroquinolones in current and archived mycoplasma gallisepticum and mycoplasma synoviae isolates from meat-type turkeys.monitoring of susceptibility to antibiotics in field isolates of pathogenic avian mycoplasmas is important for appropriate choice of treatment. our study compared in vitro susceptibility to enrofloxacin and difloxacin in recent (2005-2006) isolates of mycoplasma gallisepticum and mycoplasma synoviae from meat-type turkey flocks with archived (1997-2003) isolates and reference strains. comparison of minimal inhibitory concentration (mic) values determined by microtest, agar dilution and commercia ...200818534788
effects of prelay ts11-strain mycoplasma gallisepticum inoculation and time-specific f-strain m. gallisepticum inoculation overlays on internal egg and eggshell characteristics of commercial laying hens.mycoplasma infections are pandemic in multiage layer chicken flocks, with mycoplasma gallisepticum being the species of greatest concern to commercial egg producers. live m. gallisepticum vaccines are presently being used to help control m. gallisepticum outbreaks. however, vaccination of layers with f-strain m. gallisepticum may adversely affect egg production. in the present study, 2 trials were conducted to compare the effects of 2 currently available live mycoplasma vaccines (the ts11- and f ...200818577616
effect of selected water temperatures used in mycoplasma gallisepticum vaccine reconstitution on titer at selected time intervals.numerous methods are currently used throughout the poultry industry for the administration of vaccines. each utilizes water for vaccine reconstitution and/or administration, including two of the three commercially available live mycoplasma gallisepticum (mg) vaccines. selected water temperatures were used to reconstitute and/or dilute the three commercially available live mg vaccines. water temperatures included 4 c, 22 c (room temperature), and 32 c, and titer (color change units) was recorded ...200818646459
the potential impact of disease on the migratory structure of a partially migratory passerine population.since its introduction into eastern north america in the 1940s, the eastern population of house finches (carpodacus mexicanus) has become partially migratory, unlike its nonmigratory source population in southern california (able and belthoff in proc. r. soc. lond. 265 (1410), 2063-2071, 1998; belthoff and gauthreaux in condor 93, 374-382, 1991). the infectious disease mycoplasmal conjunctivitis (pathogen mycoplasma gallisepticum or "mg"), which has been monitored in the house finch population s ...200818716845
use of opt-out in a trial of chlamydia screening. 200818334078
effects of time-specific f-strain mycoplasma gallisepticum inoculation overlays on prelay ts11-strain mycoplasma gallisepticum inoculation on performance characteristics of commercial laying hens.mycoplasma bacteria are virtually ubiquitous in layer chicken flocks, and mycoplasma gallisepticum is the species of greatest concern to commercial egg producers. live m. gallisepticum vaccines were initially approved by the usda for use in commercial layers in 1988 to help control m. gallisepticum outbreaks. in the present study, 2 trials were conducted to determine the effects of 2 currently available live mycoplasma vaccines (the ts11-and f-strains) when used together. the following 4 inocula ...200818339985
comparative assessment of a metabolically attenuated mycoplasma gallisepticum mutant as a live vaccine for the prevention of avian respiratory mycoplasmosis.in a previous study, signature sequence mutagenesis (ssm) was used to identify a mutant with a disruption of the gene encoding the metabolic factor, dihydrolipoamide dehydrogenase, and that mutant was designated mg 7. the current study assessed the safety, immunogenicity and efficacy of mg 7 in comparison to two commercially available vaccines (ts-11 and f) as well as a laboratory vaccine strain, gt5. intratracheal vaccination of chickens with all four attenuated mutants induced varying levels o ...200818342996
a survey of avian mycoplasma species for neuraminidase enzymatic activity.among 23 currently recognized avian mycoplasma (am) species only mycoplasma gallisepticum, mycoplasma synoviae, mycoplasma meleagridis and mycoplasma iowae cause disease and loss of production in chickens and/or turkeys. because neuraminidases are considered virulence factors in many pathogenic microorganisms the aim of our study was to determine which am species possess neuraminidase enzymatic activity (neac). small samples of am cells were assayed for neac using the chromogenic substrate 5-bro ...200818372121
use of polymerase chain reactions to detect mycoplasma gallisepticum, mycoplasma imitans, mycoplasma iowae, mycoplasma meleagridis and mycoplasma synoviae in birds of prey.certain mycoplasma spp. are pathogens of poultry, but little is known of the role of mycoplasmas in disease of birds of prey. species-specific polymerase chain reactions (pcrs) for the detection of the poultry pathogens mycoplasma gallisepticum, mycoplasma imitans, mycoplasma iowae, mycoplasma meleagridis and mycoplasma synoviae were therefore evaluated for use in birds of prey. the specificities of the pcr methods were established using avian and other mycoplasmas and also selected walled bacte ...200818661307
the effects of increasing sodium chloride concentration on mycoplasma gallisepticum vaccine survival in solution.lyophilized mycoplasma gallisepticum (mg) vaccines are generally rehydrated and diluted with distilled or chlorine-free water as per manufacturer recommendations. however, as mycoplasma species lack a cell wall, this can lead to decreased viability of live vaccine during administration. the ability of phosphate-buffered saline (pbs) to prevent losses in live vaccine viability was examined. it was shown that a concentration of 1 x pbs prevented the two-fourfold decrease in mg viability seen when ...200818459310
effects of prelay 6/85-strain mycoplasma gallisepticum inoculation alone or in conjunction with the inoculation of f-strain mycoplasma gallisepticum during lay on the blood characteristics of commercial egg-laying hens.the effects of 6/85-strain mycoplasma gallisepticum (6/85mg) inoculation alone or in conjunction with f-strain m. gallisepticum (fmg) overlays and their timing on the blood characteristics of commercial egg-laying hens were investigated. control birds received sham inoculations at 10 wk of age. birds in a second treatment group were inoculated with 6/85mg at 10 wk of age, those in a third treatment group were inoculated with 6/85mg at 10 wk followed by an overlay inoculation of fmg at 22 wk, and ...200818809862
circadian serum concentrations of tylosin in broilers after feed or water medication.1. because tylosin is a time-dependent antibacterial agent, and because feeding and drinking of broilers decreases in late afternoon and ceases in the dark, it was hypothesised that serum concentrations of this drug are greatly reduced during the dark period. 2. the trial was carried out in a commercial poultry house, under standard broiler husbandry conditions, with food and water withdrawn from 22:00 until 07:00 h next morning and exposed to a natural light cycle of 13l:11d. 3. broilers were g ...200818836909
adaptation of mycoplasmas to adverse growth conditions: morphology, ultrastructure, and genome expression of mycoplasma gallisepticum s6 cells. 200818853779
control of avian mycoplasma infections in commercial poultry.control of pathogenic avian mycoplasmas can consist of one of three general approaches: maintaining flocks free of infection, medication, or vaccination. maintaining flocks free of pathogenic mycoplasmas consists of maintaining replacements from mycoplasma-free sources in a single-age, all-in all-out management system. good biosecurity and an effective monitoring system are necessary aspects of this program. medication can be very useful in preventing clinical signs and lesions, as well as econo ...200818939621
differentiation of mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from commonly used mycoplasma gallisepticum challenge strains by pcr.mycoplasma gallisepticum (mg) is an important avian pathogen causing significant economic losses within the poultry industry. in an effort to develop tools to aid in mg research and diagnostics, we have compared sequences of the attenuated mg vaccine strain ts-11 to those of commonly used pathogenic challenge strains in search of a simple means of differentiation. via gapa sequence alignments and comparisons, we have identified and designed primers facilitating strain differentiation. when appli ...200818939641
atomic force microscopy investigation of dna extracted from the vegetative forms and the viable but nonculturable forms of mycoplasma gallisepticum s6.recent studies show that mycoplasmas have various programs of life. this means that changes in morphology and genome expression may occur once the environment of these microorganisms becomes extremely altered. in this article, we report on changes in the dna molecule obtained from the vegetative forms and the viable but nonculturable (vbnc) forms of mycoplasma gallisepticum s6. atomic force microscopy studies show that the above-mentioned forms of the mycoplasma have different values of dna para ...200818979050
compatibility of a combination of tiamulin and chlortetracycline with salinomycin in feed during a pulsed medication program coadministration in broilers.in an earlier study, the continuous medication of broiler feed with a combination of tiamulin (tia; 20 mg/kg), chlortetracycline (ctc; 60 mg/kg), and the ionophore anticoccidial salinomycin (sal; 60 mg/kg) caused an initial increase in bw and feed efficiency (fe; g of weight gain/kg of feed intake). however, as doses increased to combinations of 30 mg/kg of tia and 90 mg/kg of ctc or 50 mg/kg of tia and 150 mg/kg of ctc, there was a dose-related reduction in growth rate and fe. this was thought ...200819038809
facial cellulitis induced in chickens by mycoplasma gallisepticum bacterin and its treatment.ten-to-14-day-old replacement chickens were vaccinated subcutaneously in the neck with a mycoplasma gallisepticum bacterin. a few days later, 40% of the flock developed cellulitis of the head. birds were submitted for diagnostic investigation between 4 and 6 wk of age. histology revealed lesions in the subcutis consistent with oil-emulsified vaccine/bacterin reaction. no significant bacteria were isolated from the lesions. birds were treated with 1 mg of methyl prednisol acetate intramuscularly. ...200819166067
a recombinant pvpa protein-based diagnostic prototype for rapid screening of chicken mycoplasma gallisepticum infections.mycoplasma gallisepticum is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. serological monitoring is essential to maintain mycoplasma-free breeder flocks and often complicated by the cross-reactions between different mycoplasma species. to overcome serological cross-reactions, a large fragment of the m. gallisepticum pvpa cytadhesin, species-specific surface-exposed protein, was produced in e. coli as a recombinant protein (rpvpa336) a ...200818248920
mycoplasma gallisepticum invades chicken erythrocytes during infection.recently, it was demonstrated using in vitro assays that the avian pathogen mycoplasma gallisepticum is able to invade nonphagocytic cells. it was also shown that this mycoplasma can survive and multiply intracellularly for at least 48 h and that this cell invasion capacity contributes to the systemic spread of m. gallisepticum from the respiratory tract to the inner organs. using the gentamicin invasion assay and a differential immunofluorescence technique combined with confocal laser scanning ...200817954728
mycoplasma gallisepticum as the first analyzed bacterium in which rna is not polyadenylated.the addition of poly(a)-tails to rna is a phenomenon common to almost all organisms. in addition to most eukaryotic mrnas possessing a stable poly(a)-tail, rna is polyadenylated as part of a degradation mechanism in prokaryotes, organelles, and the eukaryotic nucleus. to date, only very few systems have been described wherein rna is metabolized without polyadenylation, including several archaea and yeast mitochondria. the minimal genome of the parasitic bacteria, mycoplasma, does not encode homo ...200818399989
high inter-species and low intra-species variation in 16s-23s rdna spacer sequences of pathogenic avian mycoplasmas offers potential use as a diagnostic tool.in order to investigate its value for phylogenetic analysis, species characterisation and diagnosis, the 16s-23s rdna intergenic spacer regions (isrs) of the type strain of 23 avian mycoplasma species were amplified and the sequences determined. also sequenced were the reference strains of mycoplasma iowae serotypes j, k, n, q and r and a number of field strains of mycoplasma synoviae, mycoplasma gallisepticum, mycoplasma meleagridis and m. iowae. the isrs demonstrated a high level of size varia ...200818055138
role of phenotypic diversity in pathogenesis of avian mycoplasmosis.the interactions between avian mycoplasmas and their host cells are far more complex than might be anticipated from their apparent structural and functional simplicity. phenotypic diversity in the form of reversible phase variation, antigenic variation or size variation is an adaptive mechanism that enables avian mycoplasmas to survive in a hostile and highly evolved host. despite significant similarities between major membrane antigens of mycoplasma gallisepticum and mycoplasma synoviae, the mo ...200717994321
effects of route of inoculation on mycoplasma gallisepticum infection in captive house finches.the routes by which mycoplasma gallisepticum initiates infection during outbreaks of conjunctivitis in house finches remain uncertain. as m. gallisepticum recovered from the cloaca of chickens remains viable for up to 3 days in chicken faeces, the possibility of spread via faecal contamination has been suggested. to test the hypothesis that food or water contaminated with m. gallisepticum may initiate infection, 20 house finches were experimentally inoculated by the oral or the conjunctival rout ...200717994326
chemokine and cytokine gene expression profiles in chickens inoculated with mycoplasma gallisepticum strains rlow or gt5.mycoplasma gallisepticum infection in chickens leads to tracheitis, airsacculitis, poor feed conversion and reduced egg production, resulting in considerable economic hardship on the poultry industry. the chemokines and cytokines responsible for recruitment, activation and proliferation of leukocytes in affected tissues have not been described. in the current study, chemokine and cytokine gene expression profiles were investigated in tracheas of chickens inoculated with m. gallisepticum strains ...200718006123
recombinant plasmid constructs expressing gene for antimicrobial peptide melittin for the therapy of mycoplasma and chlamydia infections.in view of growing number of pathogenic microbial strain resistant to routine antibiotics, antimicrobial peptides become promising agents for the therapy of infectious diseases. we studied in vivo effects of melittin, an antimicrobial peptide expressed in a recombinant plasmid vector, on infection with urogenital pathogens chlamydia trachomatis, mycoplasma hominis, and mycoplasma gallisepticum. we obtained recombinant plasmid constructs, where melittin gene is under the control of tetracycline-d ...200718457054
experimental infection of chickens and turkeys with mycoplasma gallisepticum reference strain s6 and north carolina field isolate rapd type b.during an epidemic of mycoplasmosis in chicken and turkey flocks in north carolina between 1999 and 2001, isolates of mycoplasma gallisepticum (mg) from affected flocks were characterized by random amplification of polymorphic dna (rapd), and eight distinct rapd types were identified. mg rapd type b accounted for more than 90% of the isolates and was associated with moderate-to-severe clinical signs and mortality. the virulence of mg rapd type b for chickens and turkeys was compared with sham-in ...200717461274
the mycoplasma gallisepticum osmc-like protein mg1142 resides on the cell surface and binds heparin.mycoplasma gallisepticum is an avian pathogen that causes a chronic respiratory disease of chickens and results in significant economic losses to the poultry industry worldwide. colonization of the host and the establishment of chronic disease are initiated by the cytadherence of m. gallisepticum to the host respiratory epithelium. while several proteins involved in cytadhesion have been characterized, molecules that interact with components of the host extracellular matrix, a process that is ce ...200717464059
effects of supplemental dietary phytase and 25-hydroxycholecalciferol on the blood characteristics of commercial layers inoculated before or at the onset of lay with the f-strain of mycoplasma gallisepticum.in 3 trials, the effects of dietary supplementation with phytase (phy) and 25-hydroxycholecalciferol on bw and the blood characteristics of commercial layers that were inoculated prelay (12 wk of age) or at the onset of lay (22 wk of age) with f-strain mycoplasma gallisepticum were assessed at 34, 50, and 58 wk of age. experimental layer diets, which included either a basal control diet or the same diet supplemented with 0.025% phy and 25-hydroxycholecalciferol, were fed from 20 through 58 wk of ...200717369552
interlaboratory comparison of ability to detect nucleic acid of mycoplasma gallisepticum and mycoplasma synoviae by polymerase chain reaction.in recent years polymerase chain reaction (pcr) assays have become widely used as methods to confirm the presence of mycoplasma gallisepticum and mycoplasma synoviae in poultry flocks, but there has been limited standardization of the protocols used. thirteen laboratories from five different countries participated in an interlaboratory comparison of detection of m. gallisepticum and m. synoviae dna by pcr in samples that contained 10-fold dilutions of these bacteria. the concentration of bacteri ...200717479373
Displaying items 201 - 300 of 1254