Various Species Of Mycobacteria Research Articles

Superoxide dismutase from Mycobacterium species, strain Takeo.

Superoxide dismutase from Mycobacterium species, strain Takeo, has been purified to homogeneity as judged by disc gel electrophoresis and ultracentrifugation. The enzyme was found to have a molecular weight of approximately 61 500 by sedimentation equilibrium and to contain manganese by atomic absorption and electron spin resonance spectra. The amino acid composition was also determined. The enzyme was considerably stable to the treatment with sodium dodecyl sulfate; unless incubating at 80 degrees C for 2 min, it was not completely dissociated into the subunits. The molecular weight of the subunit was found to be approximately 21 000. Antibodies against the superoxide dismutase were produced by immunization of rabbits with the enzyme, and the gamma-globulin fraction was purified. Superoxide dismutase preparations obtained from various species of mycobacteria and nocardia cross-reacted to different degrees with these antibodies on the Ouchterlony double diffusion plates. Comparative immunological studies indicated that strain Takeo might be most closely related to Myobacterium smegmatis among species of mycobacteria and nocardia tested. The antibodies against superoxide dismutase may be used as a valuable tool for the classification of mycobacteria.

Studies on the nitrate reductase activity of mycobacteria in the presence of fatty acids and related compounds.

The nitrate reductase activity of mycobacteria containing nitrate reductase was strongly increased in the presence of fatty acids as well as related compounds that can act as electron donors. Mycobacteria that do not contain nitrate reductase, however, did not reduce nitrate even in the presence of such compounds. One exception was Mycobacterium scrofulaceum, which reduced nitrate to nitrite in the presence of lactic acid. These findings are significant for the differentiation and identification of various species of Mycobacteria.

Specificity of tuberculins and antigens from various species of mycobacteria.

Skin test antigen preparations from six species of Mycobacterium were studied in homologously and heterologously sensitized guinea pigs. When all antigen preparations were adjusted to a predetermin...

Methods for the separation and identification of mycobactins from various species of mycobacteria.

A single pure component was isolated from mycobactin P by countercurrent distribution; its side chain is n-cis-octadec-2-enoyl; its purity and molecular structure were confirmed by mass spectrometry of its aluminium complex. The separation of ferric and of aluminium complexes of mycobactins by thin-layer chromatography is described. Mycobacterium terrae, M. marinum and M. smegmatis produce mycobactins that differ among themselves and from mycobactins P and T. A nomenclature for the mycobactins and their derivatives is suggested.

Mycosides: a new class of type-specific glycolipids of Mycobacteria.

STUDIES by the combined techniques of chromatography and infra-red spectroscopy of the lipid content of 85 strains of Mycobacteria including human, bovine and avian species and representatives of the atypical acid-fast group1, have led to the recognition that some of the compounds are limited in distribution to a single species of organism and may in fact serve to distinguish between the various species of Mycobacteria. The distribution of these substances in the various species of Mycobacteria studied is as follows: phthiocerol dimycocerosate present in the lipids of 28 out of 30 human strains studied; a compound called G B 2,3 present in the lipids of 7 out of 7 bovine strains studied (G B is accompanied by phthiocerol dimycocerosate in virulent bovine strains); a compound called G A 4 present in the lipids of 17/17 photochromogenic1 strains; a compound called J av 4 present in the lipids of 11/13 avian strains and also in the lipids of 3/6 non-photochromogenic strains. The purpose of this communication is to propose a more rational nomenclature for these substances.

In Vitro Inhibition of Mycobacteria by Streptothricin

Aside from penicillin, streptothricin is the only antibiotic whose pharmacologic properties indicate a suitability for general use in the animal organism., Interest in the development of an antituberculosis agent of microbiological origin led to in vitro tests of the efficacy of the only 2 antibiotics known which at present could possibly be of general use in animals or humans, namely, penicillin and streptothricin. Various species of mycobacteria were totally resistant to the action of penicillin, even as much as 1,000 Oxford units per ml. Further studies revealed that this resistance probably is due to the abundant formation of a penicillin-destroying enzyme, presumably penicillinase. Details of this are reported elsewhere. A study of the inhibitory action of streptothricin for 5 Mycobacterium cultures is included in Table I. Since streptothricin is stable, a single addition of the antibiotic was sufficient to maintain the desired unitage over the period of 6 to 8 weeks necessary for growth of some strains of mycobacteria. Streptothricin was particularly effective in Long's medium; this is probably the result of the alkalinity of the medium which is known to enhance the in vitro activity of streptothricin. The inhibitory range of 0.1 to 1.0 unit of streptothricin per ml places these Mycobacterium cultures among the most sensitive organisms to streptothricin. M. phlei previously was found sensitive. A rough indication was obtained for the bactericidal action of streptothricin upon mycobacteria. Long's medium containing various quantities of streptothricin was inoculated heavily with 4 Mycobacterium strains. After 14 days' inhibition, portions of each culture were streaked on Long's agar to determine viability of the cells in the inoculum. Table II indicates that streptothricin was definitely bactericidal in low concentrations.