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PubMed1971

Serological cross-reaction between lipids of Mycoplasma pneumoniae and Mycoplasma neurolyticum.

The complement-fixing activity of crude lipid extracts of 10 Mycoplasma species was compared with that of whole organism antigens employing immune rabbit serum. Five species (M. pneumoniae, M. neurolyticum, M. granularum, M. laidlawii, and M. fermentans) showed serological activity, whereas the remaining five species (M. canis, M. felis, M. gallisepticum, M. hyorhinis, and M. pulmonis) did not show significant activity in their lipid fractions. The lipid fractions of the five species which had serological activity in their lipid fractions showed three groups of serological specificity. M. pneumoniae cross-reacted with M. neurolyticum, M. granularum cross-reacted with M. laidlawii, and M. fermentans showed specific activity. Acute and convalescent sera from human pneumonia patients from whom M. pneumoniae had been isolated showed antibody increases which could be measured nearly as well by lipids of M. neurolyticum as by those of M. pneumoniae. Only a few human convalescent sera showed antibody measureable by lipids of M. granularum, M. pneumoniae did not cross-react with M. neurolyticum by other serological parameters such as growth inhibition on agar or double immunodiffusion, indicating that only the lipid antigens of these two species cross-react.

Animals↗
PubMed2000

Modulation of cytokine profiles by the Mycoplasma superantigen Mycoplasma arthritidis mitogen parallels susceptibility to arthritis induced by M. arthritidis.

Mycoplasma arthritidis mitogen (MAM) is a potent superantigen secreted by M. arthritidis, an agent of murine arthritis. Here we compare the abilities of MAM to induce a panel of cytokines in vitro and in vivo in BALB/c and C3H/HeJ mouse strains that differ in susceptibility to mycoplasmal arthritis. Splenocytes from both mouse strains produced high levels of all cytokines by 24 h following in vitro exposure to MAM. No differences in cytokine profiles were seen irrespective of the MAM dose. However, there were striking differences in cytokine profiles present in supernatants of splenocytes that had been collected from mice after intravenous (i.v. ) injection of MAM and subsequently rechallenged with MAM in vitro. Splenocytes collected 24 and 72 h after i.v. injection of MAM and challenged in vitro with MAM showed the most marked divergence in the secreted cytokines. Type 1 cytokines were markedly elevated in C3H/HeJ cell supernatants, whereas they were depressed or remained low in BALB/c cell supernatants. In contrast, the levels of type 2 cytokines were all greatly increased in BALB/c cell cultures but were decreased or remained low in C3H/HeJ supernatants. Interleukin-12 mRNA and protein was also markedly elevated in C3H/HeJ mice, as were the levels of immunoglobulin G2a. The data indicate a major skewing in cytokine profiles to a type 1 inflammatory response in C3H/HeJ mice but to a protective type 2 response in BALB/c mice. These cytokine changes appear to be associated with the severe arthritis in C3H/HeJ mice following injection of M. arthritidis in comparison to the mild disease seen in injected BALB/c mice.

Animals↗
PubMed1968

Pneumonia due to Mycoplasma in gnotobiotic mice. IV. Localization and identification of Mycoplasma pulmonis in the bronchi of infected gnotobiotic mice by immunofluorescence and by light microscopy.

The model of pneumonia produced by intranasal inoculation of Mycoplasma pulmonis in gnotobiotic mice provided the opportunity to study the localization and identification of the infecting organisms in the tissues by immunofluorescence techniques. Frozen sections of pneumonic mouse lung were fixed in acetone, layered with rabbit anti-M. pulmonis serum, washed, layered again with fluorescein-isothiocyanate-labeled goat anti-rabbit globulin, washed again, and examined by fluorescence microscopy. A bright line of fluorescence was seen at the bronchial epithelial surface, usually in a continuous layer. Occasional masses of fluorescence were seen in the polymorphonuclear leukocytic exudate in the bronchial lumen. Sections of tissues fixed in Helle's or 10% Formalin fixatives and stained with hematoxylin and eosin were reviewed by light microscopy and revealed a zone of blue-staining material composed of tiny coccoid bodies in the same locations at the bronchial epithelial surface as in the immunofluorescent preparations and in previously reported electron microscope studies.

Animals↗
PubMed1976

Atypical mycoplasmas from sheep in Great Britain and Australia identified as Mycoplasma ovipneumoniae.

Representative strains of "lacy-colony" mycoplasmas isolated from sheep in Great Britain and Victoria (Australia) were classified as M ovipneumoniae following comparison with strain Y98 of this species. The taxonomic description of M ovipneumoniae is extended and Y98 is proposed as the type strain. A brief description is given of the isolation of M ovipneumoniae from sheep in East Anglia.

Animals↗
PubMed1990

Detection of serum antibodies against Mycoplasma gallisepticum and Mycoplasma synoviae by a dot-immunobinding technique.

Both Mycoplasma gallisepticum (MG) and M. synoviae (MS) antigens prepared for the routine haemagglutination inhibition (HI) test were diluted and absorbed to the separate pieces of durapore membrane for the measurement of dot-immunobinding (DIB) titers of test sera. Besides, durapore strips bearing both antigens were employed for a DIB test with chicken sera definitely diluted 100-fold. Shortening of reaction time of chicken sera with antigens as well as with the secondary serum markedly eliminated non-specific DIB reactions exhibited at low dilutions although the same condition was not so effective on the elimination of non-specific reactions among rabbit hyperimmune sera. Rapid and specific development of DIB antibody which continued at high titer up to 1:640 for 10 weeks postinoculation was proved in the sera of SPF chickens inoculated with MG or MS, while DIB titers of sera from uninoculated chickens remained 1:20 or lower. Non-specific reactions, which occurred in the routine serum plate agglutination test with a part of sera from the inoculated chickens, were not exhibited in the DIB as well as in the HI test with the same sera. Results of the DIB test with serum samples from 287 conventionally reared chickens definitely diluted 100-fold coincided with the results of HI test at a level of 90% with MG and 89% with MS antigen. This technique seems to be useful for a rapid, simple and specific diagnosis of avian mycoplasmosis.

Animals↗
PubMed1987

Gene expression signals in Mycoplasma hyopneumoniae and Mycoplasma capricolum.

In Mycoplasma hyopneumoniae, the single genes for 16S and 23S rRNAs are clustered in one operon from which the 5S rRNA gene is separated by more than 4 kbp. This operon, gene 2413 and gene X from M. hyopneumoniae and the 5' ends of both rRNA operons from M. capricolum were cloned and used for analysis of the following gene expression signals: promoters and terminators of the DNA-directed RNA polymerase, ribosomal binding sites of mRNA, and sites for processing of precursor rRNA. The analyses were performed by nuclease S1 protection experiments, the primer extension technique, and DNA sequencing. From these studies we conclude that putative promoter sequences in M. hyopneumoniae deviate significantly from those in Escherichia coli and Bacillus subtilis in having its -35 consensus sequence replaced by A-T rich sequences, whereas the characterized M. capricolum promoter resembles more closely a typical E. coli promoter. The other expression signals show sequences or structures similar to those found in other eubacteria, indicating related underlying principles.

Base Sequence↗
PubMed1988

Ultrastructure of Mycoplasma pneumoniae exposed to macrolide antibiotics during cultivation on a glass surface and in an organ culture, in relation to their mycoplasma-killing activity.

The macrolide antibiotics midecamycin acetate (MOM), erythromycin (EM), midecamycin (MDM), josamycin (JM) and rokitamycin (RKM) showed killing activity against Mycoplasma pneumoniae strain FH-P24. The activity of MOM, EM and JM was not influenced by the number of organisms inoculated, but that of RKM was markedly decreased by a large inoculum. Scanning electron microscopic observations showed many long filaments crossing over each other with small colonies when the organisms were cultivated on a glass surface without any drug for 72 h. When they were exposed to four times the MIC of MOM, the filamentous forms were decreased and the colonies did not grow to a large size. However, after exposure to the other macrolides, the colonies grew larger. Transmission electron micrographs revealed that intracellular vacuolization of the organisms was induced by exposure to MOM, EM and JM, but a mixture of vacuolized cells and "young" organisms was observed after exposure to MDM and RKM. In hamster tracheal organ cultures, the number of organisms was greatly decreased by exposure to four times the MIC of MOM, and the remaining filamentous and colonized organisms were lysed. However, treatment with four times the MIC of the other macrolides induced hardly any lysis of the organisms. In transmission electron micrographs, filamentous and rounded organisms filling the ribosome-like matrix could be seen on the epithelial surface. Treatment with four times the MIC of these macrolides decreased the number of organisms and vacuolized filamentous organisms could be seen on the epithelial cells.

Animals↗
PubMed1987

Mycoplasma pulmonis proteins common to murine mycoplasmas.

The proteins of Mycoplasma pulmonis were examined by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and immunoblots using the following sera: antimedium, anti-M. arthritidis, anti-M. collis, anti-M. neurolyticum, and anti-M. muris. Fifteen proteins identified as genus-common were shared by M. pulmonis and at least one other mycoplasmal species. These proteins were shown not to be medium components, based on their reaction with antimedium serum.

Animals↗
PubMed1982

Stimulation of mouse lymphocytes by a mitogen derived from Mycoplasma arthritidis. II. Cellular requirements for T cell transformation mediated by a soluble Mycoplasma mitogen.

The mitogenic property of supernatants from M. arthritidis cultures (MAS) is shown to be nonsedimentable, nondialyzable, labile to 56 degrees C for 1 hr, and active against spleen cells from both normal and germfree mice. Both viable M. arthritidis and MAS were active for T lymphocytes because anti-Thy-1 antiserum and C eliminated responsiveness. Spleen cells enriched for T lymphocytes by passage over nylon columns lost responsiveness unless supplemented with a radioresistant adherent cell population that was shown to bear Ia antigens. Evidence is also presented that the genetic control of T lymphocyte responses to the mycoplasma mitogen was exercised at the level of the Ia-bearing adherent cells. Thus adherent cells from positive responder mouse strains, but not those from nonresponder mouse strains, restored the responses of T cells from F1 hybrids between responder and nonresponder strains.

Animals↗
PubMed1980

[Mycoplasma mastitis of cattle. 8. Pathological anatomy and histology of experimental Mycoplasma bovis mastitis].

Macroscopic and histological findings, obtained from 60 udders, are described in this paper. The animals had been infected with mycoplasma bovis and slaughtered, after something between two and 21 days had elapsed from infection. The infections and, consequently, pathologico-anatomic and histological changes were found to expand rapidly over the infected quarter and, with only little time lag, across non-infected control quarters. Roughly one week from infection, the affected quarters appeared engorged, slightly enlarged, and of tough consistence, their cutting surfaces being nodular and of moderate grey-yellowish discoloration. The same quarters were clearly reduced in size, between two and three weeks after infection, and still of tough consistence, their cutting surfaces being light brown to brown-yellow and smooth. Pronounced degeneration of alveolar epithelium, exudation of neutrophilic granulocytes, differentiated in intensity, and intra-alveolar accumulation of strongly eosin-coloured homogenous substance were the histological findings recorded between four and nine days from infection. The same alterations, yet, less strongly pronounced, continued to be recordable from now reduced alveoli, between two and three weeks from infection. Lactating tissue had entirely vanished by that time. The general pattern then was characterised by extensive alveolar atrophy and inter-alveolar infiltration of plasma cells, lymphocytes, and histiocytes. These changes proved useful in diagnosis.

Animals↗
PubMed1995

[Evaluation of conventional and new generation tests for testing the humeral response to Mycoplasma pneumoniae antigens in natural infection in humans. III Use of ELISA, complement fixation and immunoelectroprecipitation tests in diagnosis of Mycoplasma pneumoniae infections--comparative analysis].

Agreement of the results of determining antibodies against M. pneumoniae was evaluated by the ELISA, complement fixation test (CFT) and immunoelectroprecipitation test (IEPT) in serum samples from 685 persons including 571 patients with respiratory tract infections and 114 clinically healthy subjects. Assuming the CF to be the reference test, a very high correlation exceeding 0.95 was found, on the basis of the calculated correlation coefficient, between the results of the CF and IEP tests and the CFT and ELISA in all immunoglobulin classes. The highest sensitivity (92.3%) was displayed by the ELISA in relation to the CF test when determining mycoplasmas antibodies of IgM and IgA + G + M classes and slightly lower sensitivity by the IEPT and ELISA when determining of IgG (83% and 82.1% respectively). The lowest sensitivity was displayed by the ELISA when determining mycoplasmal antibodies of IgA class (53.4%). Specificity of both the tests was high and exceeded 92%. Highest agreement of CFT and ELISA was obtained when detecting mycoplasmal antibodies in diagnostically significant titer in the M and A + G + M immunoglobulin classes (> 92%) while lowest agreement, although statistically significant, was obtained when detecting IgA antibodies (74.7%).

Adolescent↗
PubMed1998

Mycoplasma pneumoniae and Mycoplasma genitalium: a comparison of two closely related bacterial species.

The rapid progress in sequencing large quantities of DNA will provide an increasing number of complete genome sequences of closely related bacterial species as well as of pairs of isolates from the same species with different features, such as a pathogenic and an apathogenic representative. This opens the way to apply subtractive comparative analysis as a tool to select from the large pool of all bacterial genes a relatively small set of genes that can be correlated with the expression of a certain phenotype. These selected genes can then be the target for further functional analyses.

Bacterial Proteins↗