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Biomedical subjects

M Tsukamura

Publications and source records attributed to M Tsukamura.

At least 163 records · Page 9Linked to original sources
PubMed1981

Occurrence of Mycobacterium tuberculosis and strains of the Mycobacterium avium-M. intracellulare complex together in the sputum of patients with pulmonary tuberculosis.

Out of 97 strains of M. tuberculosis isolated from the sputum of the same number of patients, 11 were shown to consist of a mixed population of M. tuberculosis and a strain of the M. avium-M. intracellulare (MAI) complex. The most effective method for isolating strains of the MAI complex was to incubate the culture first at 42 degrees C for 3 weeks and then at 45 degrees C for 3 weeks. By this method, the growth of M. tuberculosis was suppressed, while the contaminant mycobacteria formed colonies.

Humans↗
PubMed1981

Differentiation between the genera Mycobacterium, Rhodococcus and Nocardia by susceptibility to 5-fluorouracil.

A test for susceptibility to 5-fluorouracil was useful for differentiating between species of rapidly growing mycobacteria, and for differentiating the genus Rhodococcus from the genus Nocardia. The majority of rhodococci tested were susceptible to 5-fluorouracil (20 micrograms ml-1), whereas the majority of nocardiae tested were resistant to it. Strains of Nocardia asteroides sensu stricto could be divided into two subgroups by their reaction to 5-fluorouracil.

Fluorouracil↗
PubMed1981

Studies on thin-layer chromatography after incubation with [35S]methionine as an aid to identification of mycobacteria.

Thin-layer chromatography (TLC) of ethyl ether-ethanol extracts of mycobacteria obtained after incubation with [35S]methionine is useful for differentiation among mycobacterial species, as the distribution of radioactive spots in TLC shows a characteristic pattern except for a few species, including M. intracellulare and M. gordonae. Some supplementary studies have been carried out in the present investigation and the following results have been obtained. 1. Pretreatment of bacterial cells with trichloroacetic acid (TCA) is required to remove radioactive sulfur-containing amino acids. 2. The radioactive spots that appear in TLC of the ethyl ether-ethanol extract are divided into the following groups: (1) Petroleum ether-soluble fraction (the spot at Rf value 0.95); (2) acetone-soluble (petroleum ether-insoluble) fraction (the spots at Rf values 0.50, 0.30, and 0.13--0.20); (3) ethanol-soluble (petroleum ether- and acetone-insoluble) fraction (the spot at Rf value 0.10); (4) petroleum ether-, acetone-, and ethanol-insoluble fraction (the spot at Rf value 0.00). The spot which appears in the region of Rf values 0.13--0.20 (it may appear as two spots) in the TLC of ethyl ether-ethanol extracts is composed of two compounds, one soluble in acetone and the other insoluble in acetone but soluble in ethanol. 3. Strains of the M. avium-M. intracellulare complex have been divided into three subgroups by the pattern of radioactive spots B, C, and D, which show Rf values of 0.13--0.20, 0.30, and 0.50, respectively, in the TLC of the ethyl ether-ethanol extracts. The first group shows none of these spots, and strains of the serotypes 1, 2, and 8 belong in this group. The second group shows spot B, and strains of the serotypes 4, 18, and 20 belong in this group. The third group shows spots B, C, and D, and strains of the serotype 16 belong in it.

Chemical Fractionation↗
PubMed1981

Relationship between photochromogenicity and test temperature in mycobacteria.

Although it has been recommended that photochromogenicity of mycobacteria should be tested after incubation at 25 to 30 degrees C for 2 weeks (Wayne et al., Int. J. Syst. Bacteriol. 24:412-419, 1974), our results indicate that photochromogenicity should be determined at 37 degrees C in the dark and under continuous exposure to light for 2 weeks. The test at 37 degrees C gives more stable results for Mycobacterium kansasii, Mycobacterium marinum and Mycobacterium szulgai.

Light↗