Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026936 (Mycoplasma)
 14,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Samples from the mammary tissue of 14 lactating goats (12 naturally infected and two experimentally infected) were examined for the presence of Mycoplasma agalactiae. A monoclonal antibody (5G12) was applied to formalin-fixed, paraffin-wax-embedded sections and labelled by the avidin-biotin peroxidase complex (ABC) method. Histological examination of tissue sections revealed strong immunoreactivity in all animals included in the study. Mycoplasma agalactiae antigen was mainly detected in the cellular debris at the periphery of purulent exudates present within lactiferous sinuses, and lactiferous and interlobular ducts. In addition, M. agalactiae organisms appeared in the cytoplasm of the epithelium of ducts, and in infiltrating macrophages and neutrophils within the ducts, alveoli, interstitial tissue and regional lymph node sinuses. It is concluded that this monoclonal antibody-based immunohistochemical technique is an efficient and specific method for the post-mortem detection of M. agalactiae in cases of clinical mastitis as well as being a useful tool for the study of the route of infection and cellular types involved during mastitis caused by this organism.
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PMID:Immunohistochemical detection of Mycoplasma agalactiae in formalin-fixed, paraffin-embedded tissues from naturally and experimentally infected goats. 1212 Oct 42

The growth and pathogenicity of Mycoplasma mycoides var. capri were studied in chicken embryo tracheal rings in rolled tubes. In these organ cultures, M. mycoides var. capri attained titers of 10(7) to 10(8) color-changing units/ml of Eagle's medium and there was inhibition of ciliary activity. The rapidity of inhibition was directly related to the number of organisms inoculated. Growth of organisms was closely associated with the tracheal tissue because multiplication was not demonstrated in "conditioned medium," that is Eagle's medium from which the rings had been removed. Mycoplasma growth occurred when the cultures were incubated at 37 C, 33 C, and room temperature, but the cilia-stopping effect (CSE) was most rapid at 37 C and was not demonstrable at room temperature. Furthermore, there was no CSE when cultures were maintained in medium in which M. mycoides var. capri had been grown but was either filtered to remove the organisms or treated with tetracycline to stop their multiplication. This indicated that the CSE of M. mycoides var. capri was dependent upon a close association of multiplying organisms with the tracheal rings and was not due to toxic products persisting in the medium. Chicken tracheal epithelial cells did not adsorb to colonies of M. mycoides var. capri but HeLa cells did. Although their adsorption was unaffected by prior neuraminidase treatment, the addition of neuraminidase to the tracheal organ culture system delayed the CSE of M. mycoides var. capri. Peroxide production was demonstrated in M. mycoides var. capri-infected tracheal rings but not in uninfected cultures. The addition of glucose to the organ cultures delayed the CSE of M. mycoides var. capri, possibly because of the stimulation of peroxidase activity. Similarily, catalase protected the cilia from the usual damaging effect of M. mycoides var. capri. This protective effect was partially reversed by the addition of 3-amino-1, 2, 4,-triazole and it did not occur if the catalase had been inactivated by boiling. The addition of hydrogen peroxide to tracheal cultures also resulted in loss of ciliary activity. The present results show that the liberation of peroxide is an important factor in the pathogenesis of M. mycoides var. capri infection of chicken tracheal organ cultures. It is speculated that this also may be so in the natural host.
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PMID:Growth and Pathogenesis of Mycoplasma mycoides var. capri in Chicken Embryo Tracheal Organ Cultures. 1655 57

H(2)O(2) levels accumulated by Mycoplasma pneumoniae can be influenced by carbon source, different horse sera, yeast extract, thallium acetate, or growth in a simplified, dialyzed medium. Thus, increased levels of H(2)O(2) were detected by growth in glycerol, by omission of thallium acetate, and by the use of dialyzed medium. The ability of M. pneumoniae in the presence of glucose, but not with fructose, mannose, or glycerol, to remove both endogenous and exogenous H(2)O(2) suggests an inducible peroxidase similar to bacterial enzymes in streptococci. This peroxidase-like activity is in turn influenced by the complex interplay of medium components, explaining perhaps some of the variability of H(2)O(2) accumulations observed with glucose. A survival value has been suggested for this "peroxidase-like" activity.
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PMID:Effect of Medium on H(2)O(2) Levels and Peroxidase-Like Activity by Mycoplasma pneumoniae. 1655 50

The variant of enzyme-linked immunosorbent assay (ELISA) for detection of Mycoplasma pneumoniae (Mp) antigens in sera of patients with respiratory infections was developed. Sensitivity of detection of soluble antigens of Mp in modeling experiment varied from 1.5 to 1.0 ng/ml (on protein). Approbation of the assay was performed using 50 serum samples obtained from patients with confirmed diagnosis of respiratory mycoplasmosis. In the ELISA test Mp antigens were detected in 96% of samples. Obtained results were confirmed by testing of these serum samples and isolated from them circulating immune complexes (CICs) in immunoblotting using polyclonal antibodies labeled by horse-radish peroxidase. Mp antigenswere detected both in free state and as components of CICs. Specific reaction was observed with proteins, which molecular mass varied from 30 to 170 kDa (30, 37, 45, 56, 58, 72, 90, 130 and 170 (160) kDa). Obtained results point to appropriateness of use of developed assay for detection Mp antigens in sera of patients with respiratory infections.
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PMID:[Development of enzyme-linked immunosorbent assay for detection of Mycoplasma pneumoniae antigens]. 1881 12

A blocking ELISA based on the monoclonal antibody (MAb) 1A7 was developed to detect antibodies against Mycoplasma suis. The MAb was produced by immunising BALB/c mice with recombinant MSG1 protein (rMSG1) from M. suis expressed in E. coli. Following identification by Western blotting, the MAb was purified and labelled with horseradish peroxidase. The parameters of the ELISA were optimised, and the cut-off value determined as 36.35% by analysing the percentage inhibition of M. suis negative serum. The sensitivity and specificity of the ELISA were 92% and 100%, respectively. In repeatability tests, the intra- and inter-batch variation coefficients were <10%. The results suggest this blocking ELISA is specific, sensitive and reproducible, and will be a valuable tool in the serodiagnosis of M. suis infection in pigs.
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PMID:Use of MSG1 protein in a novel blocking ELISA for the detection of Mycoplasma suis infection. 2228 43

Mycoplasma genitalium is the smallest self-replicating bacterium and an important human pathogen responsible for a range of urogenital infections and pathologies. Due to its limited genome size, many genes conserved in other bacteria are missing in M. genitalium. Genes encoding catalase and superoxide dismutase are absent, and how this pathogen overcomes oxidative stress remains poorly understood. In this study, we characterized MG_427, a homolog of the conserved osmC, which encodes hydroperoxide peroxidase, shown to protect bacteria against oxidative stress. We found that recombinant MG_427 protein reduced organic and inorganic peroxide substrates. Also, we showed that a deletion mutant of MG_427 was highly sensitive to killing by tert-butyl hydroperoxide and H2O2 compared to the sensitivity of the wild type. Further, the fully complemented mutant strain reversed its oxidative sensitivity. Examination of the expression pattern of MG_427 during osmotic shock, oxidative stress, and other stress conditions revealed its lack of induction, distinguishing MG_427 from other previously characterized osmC genes.
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PMID:Functional characterization of osmotically inducible protein C (MG_427) from Mycoplasma genitalium. 2436 46

Mycoplasma bovis is a major bovine pathogen that causes considerable economic losses in the cattle industry worldwide. Moreover, M. bovis biofilm can persist in the environment and its host. To date, M. bovis biofilm antigens recognized by bovine convalescent sera and their comparison with planktonic cells have not yet been explored. This study utilized an immunoproteomic approach using two-dimensional electrophoresis, immunoblotting using convalescent bovine serum, and subsequent matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) to identify the immunoreactive proteins expressed in biofilm- and planktonic-grown M. bovis strain 08M. Results showed that M. bovis biofilms and planktonic cells demonstrate differential immunoreactivity to bovine convalescent serum for the first time. A total of 10 and 8 immunoreactive proteins were identified for biofilms and planktonic cells, respectively. To our knowledge, a total of 12 out of 15 had not been reported as immunoreactive proteins in M. bovis, and six were specific to M. bovis biofilms. Three proteins, namely, endoglucanase, thiol peroxidase, and one putative membrane protein, that is, mycoplasma immunogenic lipase A, were identified in planktonic cells and biofilms. Most of the identified proteins were cytoplasmic proteins that were mainly involved in transport and metabolism. Moreover, ATP binding, oxidoreductase activity, and GTP binding were their most representative molecular functions. DnaK and Tuf appeared to be the most interactive immunoreactive agent among the identified proteins. Furthermore, six proteins had potential as serodiagnostic antigens. These data will be helpful to improve our current understanding on the host response to M. bovis biofilms and planktonic cells, which may facilitate the development of novel molecular candidates of improved diagnostics and vaccines to prevent M. bovis infections.
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PMID:Differential Immunoreactivity to Bovine Convalescent Serum Between Mycoplasma bovis Biofilms and Planktonic Cells Revealed by Comparative Immunoproteomic Analysis. 2955 25

Mycoplasma pneumoniae (M. pneumoniae), as an obligate parasite, has evolved a protective strategy for coping with oxidative challenges caused by M. pneumoniae itself as well as the host immune system. However, to date, few antioxidant enzymes have been identified in mycoplasmas. In this report, we identified a protein encoded by the mpn668 gene from M. pneumoniae with a putative function as an organic hydroperoxide reductase (Ohr). The results indicated that the recombinant 140 amino acid protein, designated rMPN668, displayed hydroperoxidase activity towards both organic (tert-butyl hydroperoxide) and inorganic (hydrogen peroxide) hydroperoxides in the presence of a reducing agent such as dithiothreitol. Moreover, the expression of mpn668 in M. pneumoniae is upregulated in response to oxidative stress. Additionally, homology modeling of MPN668 and a molecular dynamics simulation suggest that both Cys55 and Cys119 form part of the active site of the protein. Mutants in which Cys55 or Cys119 were replaced with a serine lack antioxidant activity, indicating that MPN668 is a Cys-based peroxidase, consistent with it representing a new member of the Ohr family.
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PMID:The mpn668 gene of Mycoplasma pneumoniae encodes a novel organic hydroperoxide resistance protein. 2989 Nov 93


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