Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
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
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
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
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
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
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
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
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
[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
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
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
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
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
adaptation of mycoplasmas to adverse environments: phytopathogenicity and peculiarities of protein expression of vegetative and nonculturable forms of mycoplasma gallisepticum s6 cells. 200920848917
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
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
[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
systematic search for putative new domain families in mycoplasma gallisepticum genome.abstract:201020384986
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
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
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
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
animal behaviour: an ill wind for finches. 201020164914
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
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
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&emsp14;bp deletion in the 3' end of the cysp gene. in the same cysp region, all m. gallisepticum strains sh ...201020966088
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
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
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
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
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
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
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
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
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
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
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
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
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
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
effects of single and combined mycoplasma gallisepticum vaccinations on blood electrolytes and acid-base balance in commercial egg-laying hens.a previous study from our laboratory on f-strain mycoplasma gallisepticum-inoculated layers showed a significant increase in arterial partial pressure of oxygen (po(2)), which is generally associated with an oxygen-dependent improvement in tissue oxygenation. the aim of this study was to determine whether a killed (bacterin) and live ts-11-strain m. gallisepticum (ts-11-mg) vaccine treatment combination could further enhance the arterial po(2) levels in layer chickens. the experiment was conduct ...201121248332
preparation of reference strains for validation and comparison of mycoplasma testing methods.aims: to optimize growth conditions for preparation of stocks of mycoplasma reference strains to obtain highly viable and disperse samples with low ratios of genomic copy (gc) number to that of colony forming units (cfu). these stocks are required for assessment of relative limits of detection (lod) of alternative nucleic acid testing (nat)-based methods in comparison to the conventional microbiological methods. methods and results: a kinetics study was used to assess the changes in ratios bet ...201121794032
molecular characterization of mycoplasma gallisepticum isolates from jordan.two groups of mycoplasma gallisepticum (mg) isolates (n = 24) from jordan were analyzed by molecular methods and compared with other middle eastern isolates, related international isolates, and reference strains. the first group (n = 19) was isolated from july 2004 to january 2005 (isolation period a), and the newer group (n = 5) from june 2007 to april 2008 (isolation period b). the groups of isolates are from chicken flocks from northern jordan, but are not from the same farms. none of the flo ...201121793435
local immunity of the respiratory mucosal system in chickens and turkeys.this review article presents fundamental mechanisms of the local mucosal immunity in selected regions of the respiratory tract in healthy birds and in some pathological conditions. the respiratory system, whose mucosa come into direct contact with microorganisms contaminating inhaled air, has some associated structures, such as harderian gland (hg), conjunctive-associated lymphoid tissue (calt) and paranasal glands (pg), whose participation in local mechanisms of the mucosal immunity has been co ...201121721419
pathologic lesions caused by coinfection of mycoplasma gallisepticum and h3n8 low pathogenic avian influenza virus in chickens.chickens were infected under experimental conditions with mycoplasma gallisepticum and low pathogenic avian influenza (lpai) strain a/mallard/hungary/19616/07 (h3n8). two groups of chickens were aerosol challenged with m. gallisepticum strain 1226. seven days later, one of these groups and one mycoplasma-free group was challenged with lpai h3n8 virus; one group without challenge remained as negative control. eight days later, the birds were euthanized and examined for gross pathologic and histol ...201121825309
neuraminidase of mycoplasma synoviae desialylates heavy chain of the chicken immunoglobulin g and glycoproteins of chicken tracheal mucus.major poultry pathogens, mycoplasma gallisepticum and mycoplasma synoviae share several genes, including nanh that encodes their sialidases (neuraminidases). previous studies have shown considerable differences in neuraminidase enzymatic activity (neac) in m. synoviae strains and neac absence in individual cultures of two strains, ulb 925 and ulb 9122. the present study shows that the cultures lacking neac did not express nanh neuraminidase detectable by specific antibodies. in cultures of m. sy ...201121711189
towards a genome based taxonomy of mycoplasmas.mycoplasmas are gram-positive wall-less bacteria with a wide environmental and host distribution, causing disease in man and in (wild and farmed) animals. the aim of this study was to analyze the usefulness of a genomic taxonomic approach in mycoplasma systematics. multilocus sequence analysis (mlsa), average amino acid identity (aai), and karlin genomic signature allowed a clear identification of species. for instance, mycoplasma pneumoniae and mycoplasma genitalium had only 71% mlsa similarity ...201121840423
mycoplasma gallisepticum infection in the grey partridge perdix perdix: outbreak description, histopathology, biochemistry and antioxidant parameters.the grey partridge is an important game bird in europe that has declined considerably over the last decades. the production and release of farm-bred birds can be threatened by infectious agents. the objective of this study was to describe the outbreak, pathology, and blood and tissue biochemical responses in a flock of grey partridges naturally infected with mycoplasma gallisepticum.201121740554
gapa+ mycoplasma gallisepticum ts-11 has improved vaccine characteristics.mycoplasma gallisepticum (mg) is an important poultry pathogen that causes respiratory disease and loss of production worldwide, and is currently controlled with live attenuated vaccines. these vaccines have limitations as they vary in their pathogenicity, the protection afforded and their transmissibility, but have been shown to effectively reduce losses associated with challenge in the field. a live attenuated vaccine, ts-11, has been used for the control of m. gallisepticum in several countri ...201121310786
Serologic response of roosters to gradient dosage levels of a commercially available live F strain-derived Mycoplasma gallisepticum vaccine over time.Spray application is a commonly used, time- and labor-efficient means to deliver live Mycoplasma gallisepticum (MG) vaccine to laying hens in commercial production facilities. The dosage of vaccine received by spray-vaccinated birds can vary due to variation in the spray plume and the vaccine suspension droplet trajectory. In this study, a total of 48 Hy-Line W-36 males were placed individually in isolation units following eye-drop application of gradient levels (1 x, 10(-1) x, 10(-2) x, 10(-3) ...201122017053
detection and differentiation of avian mycoplasmas by surface-enhanced raman spectroscopy based on silver nanorod array.mycoplasma gallisepticum is a bacterial pathogen of poultry that is estimated to cause annual losses exceeding $780 million. the national poultry improvement plan guidelines recommend regular surveillance and intervention strategies to contain m. gallisepticum infections and ensure mycoplasma-free avian stocks, but several factors make its detection and diagnosis a major challenge. current techniques are laborious, require special expertise, and are typically plagued by false results. in this st ...201122210215
analysis of the 16s to 23s rrna intergenic spacer region of mycoplasma synoviae field strains.mycoplasma synoviae has been associated with economic loss in the chicken and turkey industries. the molecular characterization of m. synoviae at strain level allows the analysis of relationships between strains that may be valuable in epidemiological investigations. in the present study, the intergenic spacer region (isr) between the 16s and 23s rrna genes was examined to see whether useful information about strains could be derived. m. synoviae has two copies of this region, which may not be e ...201121331951
development and immunogenicity of recombinant gapa(+) mycoplasma gallisepticum vaccine strain ts-11 expressing infectious bronchitis virus-s1 glycoprotein and chicken interleukin-6.mycoplasma gallisepticum (mg) is a major pathogen of poultry that causes chronic respiratory disease in chickens and infectious sinusitis in turkeys. a live attenuated vaccine, ts-11, has been used for the control of mg in several countries. the efficacy of this vaccine is highly dose dependent and the flock antibody response is weak. to improve the functionality of the vaccine and investigate its potential as a delivery vector for foreign antigens and immunomodulatory proteins, we developed a d ...201121354248
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
seroprevalence of salmonella and mycoplasma infection in backyard chickens in the state of entre rios in argentina.the present work was conducted to study the seroprevalence of salmonella, mycoplasma gallisepticum (mg), and mycoplasma synoviae (ms) infection in backyard chickens located in entre ríos, argentina, over 3 periods of time. a total of 2,441 sera samples were collected from backyard chickens belonging to 256 family farms in 16 counties in the state of entre ríos from january to may 2003 (first period), december 2004 to april 2005 (second period), and october 2006 to may 2007 (third period). the pr ...201121406358
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
[comparative proteomic characteristic of mycoplasmas (mollycutes)].saturating proteome identification and the study of post-translational protein modifications of acholeplasma laidlawii using combination of single- and two-dimension gel electrophoresis followed by mass-spectrometry analysis have been carried out. results were compared to the earlier identified proteome of mycoplasma gallisepticum. it was found that m. gallisepticum and a. laidlawii express 61 and 58% of the annotated orfs respectively. all subunits of dna-polymerase iii were identified during o ...201121460883
biological characterization of russian mycoplasma gallisepticum field isolates.an earlier study on commercial chickens and turkeys with a history of respiratory disease established mycoplasma gallisepticum infection rates on 164 poultry farms of the russian federation. forty-seven (29%) of these poultry farms were m. gallisepticum-positive by polymerase chain reaction but isolation of the mycoplasma was successful only on 10 farms. five field isolates from different farms were selected for pathogenicity studies in specific pathogen-free chicks. clinical signs, seroconversi ...201121500042
biosecurity on a multiple-age egg production complex: a 15-year experience.a multiple-age egg production farm was conceived, designed, constructed, and managed with the goal of blocking the introduction of preventable poultry diseases and infestations. fifteen years after conception and 13 years after housing the first hens, the 4 million-hen farm remains free of mycoplasma gallisepticum, infectious laryngotracheitis, and ornithonyssus sylviarum. annual savings in vaccine use exceed the estimated annual costs of the biosecurity program. the cumulative design, construct ...201121500651
extracellular vesicles derived from acholeplasma laidlawii pg8.extracellular vesicle production is believed to be a ubiquitous process in bacteria, but the data on such a process in mollicutes are absent. we report the isolation of ultramicroforms - extracellular vesicles from supernatants of acholeplasma laidlawii pg8 (ubiquitous mycoplasma; the main contaminant of cell culture). considering sizes, morphology, and ultrastructural organization, the ultramicroforms of a. laidlawii pg8 are similar to membrane vesicles of gram-positive and gram-negative bacter ...201121623458
the mycoplasma gallisepticum α-enolase is cell surface-exposed and mediates adherence by binding to chicken plasminogen.the α-enolase protein is reported to be an adhesin in several pathogenic bacterial species, but its role in mycoplasma gallisepticum is unknown. in this study, the m. gallisepticum α-enolase gene was adapted to heterologous expression in escherichia coli by performing overlapping polymerase chain reaction with site-directed mutagenesis to introduce a960g and a1158g mutations in the nucleotide sequence. the full-length mutated gene was cloned into a pgem-t easy vector and subcloned into the ex ...201121664449
mycoplasma gallisepticum experimental infection and tissue distribution in chickens, sparrows and pigeons.the most effective approaches to control the spread of mycoplasma gallisepticum include strict biosecurity measures, continuous surveillance and eradication of infected flocks. the rapid expansion of the poultry industry worldwide in restricted geographical areas and severe economic losses due to m. gallisepticum outbreaks make it crucial to identify and better control the vectors responsible for the transmission of the disease. in the present study we evaluated the susceptibility of sparrows an ...201121812712
characterization of in vivo-acquired resistance to macrolides of mycoplasma gallisepticum strains isolated from poultry.abstract: the macrolide class of antibiotics, including tylosin and tilmicosin, is widely used in the veterinary field for prophylaxis and treatment of mycoplasmosis. in vitro susceptibility testing of 50 strains of m. gallisepticum isolated in israel during the period 1997-2010 revealed that acquired resistance to tylosin as well as to tilmicosin was present in 50% of them. moreover, 72% (13/18) of the strains isolated from clinical samples since 2006 showed acquired resistance to enrofloxacin, ...201121810258
an adhesion molecule-based colloidal gold immunochromatography assay strip for rapidly and specifically detecting chicken antibodies against mycoplasma gallisepticum.the fragment of the vlha1.2 gene was cloned from a mycoplasma gallisepticum (mg) dna library by serial pcrs after the same-sense mutagenesis of three tga codons encoding tryptophan (trp). following transforming the generated plasmid of pkg-vlha1.2, the recombinant vlha1.2-gst fusion protein of 92kda was induced and recognized by anti-mg sera. after gst-affinity chromatographic purification, the vlha-based colloidal gold immunochromatography assay (gica) strips were generated. the gica strips spe ...201120630551
Effects of sialidase knockout and complementation on virulence of Mycoplasma gallisepticum.Reannotation of the pathogenic Mycoplasma gallisepticum strain R(low) genome identified the hypothetical gene MGA_0329 as a homolog of the sialidase gene MS53_0199 of Mycoplasma synoviae strain MS53. Potent sialidase activity was subsequently quantitated in several M. gallisepticum strains. Because sialidase activity levels correlate significantly with differing M. synoviae strain virulence, we hypothesized this enzyme may also influence the virulence of M. gallisepticum. MGA_0329 was disrupted ...201122197303
Cross-Genome Comparisons of Newly Identified Domains in Mycoplasma gallisepticum and Domain Architectures with Other Mycoplasma species.Accurate functional annotation of protein sequences is hampered by important factors such as the failure of sequence search methods to identify relationships and the inherent diversity in function of proteins related at low sequence similarities. Earlier, we had employed intermediate sequence search approach to establish new domain relationships in the unassigned regions of gene products at the whole genome level by taking Mycoplasma gallisepticum as a specific example and established new domain ...201121860605
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
mycoplasma gallisepticum in pheasants and the efficacy of tylvalosin to treat the disease.infectious sinusitis, a common condition seen in adult pheasants, is primarily caused by mycoplasma gallisepticum. the aims of the present study were to investigate the pathogenicity of m. gallisepticum in 14-day-old pheasants and evaluate the macrolide antibiotic tylvalosin (tvn) as a treatment for infectious sinusitis. the minimum inhibitory concentration of tvn for five isolates of m. gallisepticum taken from pheasants confirmed their susceptibility to tvn (range: 0.002 to 0.008 µg/ml). one o ...201122107092
comparison of blood values and health status of floreana mockingbirds (mimus trifasciatus) on the islands of champion and gardner-by-floreana, galápagos islands.the floreana mockingbird (mimus trifasciatus) is one of the rarest bird species in the world, with an estimated 550 individuals remaining on two rocky islets off the coast of floreana, galápagos, ecuador, from which the main population was extirpated more than 100 yr ago. because they have been listed in critical danger of extinction, a plan to reintroduce this species to floreana has been initiated. determining the health status of the source mockingbird populations is a top priority within the ...201121270000
the spread of pathogens through trade in poultry hatching eggs: overview and recent developments.the international trade in poultry hatching eggs could potentially facilitate the global dissemination of poultry disease. provided the guidelines of the world organisation for animal health (oie) on breeding flock hygiene are followed, of those avian diseases currently listed by the ole, only highly pathogenic avian influenza (hpai), newcastle disease (nd), and avian mycoplasmosis (caused by mycoplasma gallisepticum or m. synoviae) should be considered likely to be spread though trade in this c ...201121809762
experimental infection of domestic canaries (serinus canaria domestica) with mycoplasma gallisepticum: a new model system for a wildlife disease.the ethical and logistical challenges inherent in experimental infections of wild-caught animals present a key limitation to the study of wildlife diseases. here we characterize a potentially useful domestic model for a wildlife disease that has been of particular interest in recent decades; that is, infection of north american house finches (carpodacus mexicanus) with mycoplasma gallisepticum, more commonly known as a worldwide poultry pathogen. seven domestic canaries (serinus canaria domestic ...201121711192
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
characterization of a ts-1-like mycoplasma galisepticum isolate from commercial broiler chickens.several commercial broiler flocks in northeastern georgia that were the progeny of the same parent flock (flock 40) were diagnosed as mycoplasma gallisepticum (mg) positive by serology, culture, and pcr. flock 40 had been vaccinated with ts-11 live mg vaccine. several isolates were obtained from the mg-positive broiler flocks, and these isolates were indistinguishable from the ts-11 vaccine strain by the molecular strain differentiation methods used. a pathogenicity study was performed to compar ...201122312975
contrasting epidemic histories reveal pathogen-mediated balancing selection on class ii mhc diversity in a wild songbird.the extent to which pathogens maintain the extraordinary polymorphism at vertebrate major histocompatibility complex (mhc) genes via balancing selection has intrigued evolutionary biologists for over half a century, but direct tests remain challenging. here we examine whether a well-characterized epidemic of mycoplasmal conjunctivitis resulted in balancing selection on class ii mhc in a wild songbird host, the house finch (carpodacus mexicanus). first, we confirmed the potential for pathogen-med ...201222291920
experimental evidence for distinct costs of pathogenesis and immunity against a natural pathogen in a wild bird.protective immunity is expected to evolve when the costs of mounting an immune response are less than those of harbouring pathogens. estimating the costs of immunity vs. pathogenesis in natural systems is challenging, however, because they are typically closely linked. here we attempt to disentangle the relative cost of each using experimental infections in a natural host-parasite system in which hosts (house finches, carpodacus mexicanus) differ in resistance to a bacterium (mycoplasma gallisep ...201222924889
seroprevalence of newcastle disease and other infectious diseases in backyard chickens at markets in eastern shewa zone, ethiopia.this study was conducted to estimate the seroprevalence of newcastle disease (nd), pasteurella multocida (pm) infection, mycoplasma gallisepticum (mg) infection, and infectious bursal disease (ibd) and to assess the level of concurrent seropositivity during the dry and wet seasons of the year 2010. in total, 234 and 216 sera were collected during the dry and wet seasons, respectively, from unvaccinated backyard chickens at 4 live poultry markets in 2 woredas (districts) of eastern shewa zone, et ...201222399725
ultrafast evolution and loss of crisprs following a host shift in a novel wildlife pathogen, mycoplasma gallisepticum.measureable rates of genome evolution are well documented in human pathogens but are less well understood in bacterial pathogens in the wild, particularly during and after host switches. mycoplasma gallisepticum (mg) is a pathogenic bacterium that has evolved predominantly in poultry and recently jumped to wild house finches (carpodacus mexicanus), a common north american songbird. for the first time we characterize the genome and measure rates of genome evolution in house finch isolates of mg, ...201222346765
a comparative study of live attenuated f strain-derived mycoplasma gallisepticum vaccines.commercially available attenuated strains of mycoplasma gallisepticum (mg) are commonly used within the layer industry to control mg-induced mycoplasmosis. among these are two live mg vaccines derived from the moderately pathogenic mg "chick f" strain. in the present study, the commercially available f strain derivatives were compared for their ability to elicit seroconversion, persist in vivo, and protect against virulent mg-induced airsacculitis. in addition, a noncommercial laboratory-derived ...201222856200
influence of swab material on the detection of mycoplasma gallisepticum and mycoplasma synoviae by real-time pcr.recent reports have shown an increased recovery of cells from flocked nylon swabs which may improve the specimen quality and the real sensitivity of diagnostic tests in a clinical setting. in this study, the detection of mycoplasma gallisepticum (mg) and m. synoviae (ms), using dry swabs of different materials (nylon flocked, cotton, and polyester), was investigated using real-time taqman pcr protocols. different types of samples, including dilutions of pure broth cultures of mg and ms as well a ...201222856187
the efficacy of three commercial mycoplasma gallisepticum vaccines in laying hens.the efficacy of three commercial mycoplasma gallisepticum (mg) immunizing agents-a bacterin, a recombinant fowlpox-mg vaccine, and a live f-strain vaccine-was compared in specific-pathogen-free hens in egg production. three groups of 25 chickens were vaccinated with one of the vaccines at 10 wk of age and 25 birds were not vaccinated. at 25 wk of age (and approximately 50% egg production), 20 birds from each of the three vaccinated groups and 15 nonvaccinated controls were challenged with virule ...201222856181
identification of biofilm formation by mycoplasma gallisepticum.mycoplasma gallisepticum is the causative agent of chronic respiratory disease in chickens and of infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages. this study investigated the biofilm-producing ability of m. gallisepticum strains in an attempt to explain its intriguing persistence in commercial flocks. eleven strains of m. gallisepticum were investigated for their biofilm formation, which varied considerably. strains nobilis mg 6/85, s(6) (p(5) and ...201222840542
mycoplasma gallisepticum transmission: comparison of commercial f-strain vaccine versus layer complex-derived field strains in a tunnel ventilated house.two simultaneous trials were conducted using a commercially available, live, f strain mycoplasma gallisepticum (fmg) vaccine (trial 1) or 2 inocula of layer complex-derived mg strains (lcd-mg; trial 2). in each of the 2 trials, 4 commercial turkeys were housed in each of 2 adjoining pens immediately adjacent to air inlets. the turkeys (8/trial) were inoculated in the right eye with either a 1× dose of fmg (trial 1) or with 0.02 ml of 1 of 2 actively growing lcd-mg inocula (4 turkeys/inoculum; tr ...201223155015
a novel transposon construct expressing phoa with potential for studying protein expression and translocation in mycoplasma gallisepticum.mycoplasma gallisepticum is a major poultry pathogen and causes severe economic loss to the poultry industry. in mycoplasmas lipoproteins are abundant on the membrane surface and play a critical role in interactions with the host, but tools for exploring their molecular biology are limited.201222770122
extensive variation in surface lipoprotein gene content and genomic changes associated with virulence during evolution of a novel north american house finch epizootic strain of mycoplasma gallisepticum.mycoplasma gallisepticum, a significant respiratory and reproductive pathogen of domestic poultry, has since 1994 been recognized as an emergent pathogen of the american house finch (carpodacus mexicanus). epizootic spread and pathognomonic characteristics of house finch-associated mycoplasma gallisepticum (hfmg) have been studied as a model of an emergent to endemic pathogen in a novel host. here we present comparative analysis of eight hfmg genomes, including one from an index isolate and seve ...201222628486
evaluation of mycoplasma gallisepticum k-strain as a live vaccine in chickens.we evaluated the pathogenicity of three live mycoplasma gallisepticum (mg) vaccine candidates by infection via aerosol of 3-wk-old chickens with log phase broth cultures (trial 1). two of the candidates (k3020 and k4649a) colonized only 10% and 20% of the chickens, respectively, unlike k2101 (k-strain), which was reisolated from all of the vaccinated chickens tested. k-strain inoculation did not result in significant air sac or tracheal lesions in chickens at 10 and 39 days postinfection (p < or ...201222545527
conjunctivitis, rhinitis, and sinusitis in cliff swallows (petrochelidon pyrrhonota) found in association with mycoplasma sturni infection and cryptosporidiosis.fledgling cliff swallows were cared for at a rehabilitation facility when clinical signs of ocular disease, characterized by conjunctivitis, epiphora, and hyperaemia of palpebrae and nictitans, were recognized. treatment consisted of topical and oral antibiotic therapy and one topical steroid administration. however, one cliff swallow died and three were killed due to poor therapeutic response. conjunctival swabs were obtained ante-mortem from the three cliff swallows and were submitted for myco ...201222834555
within-host dynamics of mycoplasma infections: conjunctivitis in wild passerine birds.the host-pathogen interaction drives infectious disease dynamics at the individual, population and community levels. here i present and analyze a model of the vertebrate immune response to mycoplasma infections, and use it to identify which pathogen and host immune characteristics drive patterns of mycoplasma gallisepticum (mg) infections in the house finch (carpodacus mexicanus) and other passerine birds. i also address which host and pathogen characteristics most affect host infectiousness and ...201222726809
discrepancy between minimal inhibitory concentration to enrofloxacin and mutations present in the quinolone-resistance determining regions of mycoplasma gallisepticum field strains.molecular characterization of the quinolone-resistance determining regions (qrdrs) of dna gyrase and topoisomerase iv in 93 mycoplasma gallisepticum field strains isolated in different geographic regions revealed discrepancies between minimal inhibitory concentration values and presence of amino acid substitutions within the qrdrs of gyra and parc in 9/93 (10%) strains. this may delimitate applicability of a gene-based assay to detect fluoroquinolone resistance in this avian pathogen.201222655973
understanding the origin of seasonal epidemics of mycoplasmal conjunctivitis.1. many host-pathogen systems show regular seasonal oscillations. 2. seasonal variation in mycoplasmal conjunctivitis prevalence in house finches is an example of such oscillations. 3. an annual pulse of mycoplasma gallisepticum-naïve juveniles increasing the number of susceptibles, seasonal changes in flocking behaviour increasing transmission rate and a gradual loss of resistance to reinfection with time are sufficient to model the observed seasonal variation in disease prevalence. nevertheles ...201222524311
innate immunity and the evolution of resistance to an emerging infectious disease in a wild bird.innate immunity is expected to play a primary role in conferring resistance to novel infectious diseases, but few studies have attempted to examine its role in the evolution of resistance to emerging pathogens in wild vertebrate populations. here, we used experimental infections and cdna microarrays to examine whether changes in the innate and/or acquired immune responses likely accompanied the emergence of resistance in house finches (carpodacus mexicanus) in the eastern united states subject t ...201222512302
Refresh
firstprev
...111213
nextlast
Displaying items 1001 - 1100 of 1254