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Biomedical subjects

M Tsukamura

Publications and source records attributed to M Tsukamura.

At least 253 records · Page 14Linked to original sources

Cross-resistant relationships among the aminoglucoside antibiotics in Mycobacterium tuberculosis.

Phenotypes of isolates of Mycobacterium tuberculosis H37RV showing resistance to the aminoglucoside antibiotics streptomycin, viomycin, kanamycin, capreomycin, tuberactinomycin N, lividomycin and paromomycin could be grouped into the following types: (I) resistant only to different levels of streptomycins; (2) resistant only to a low level of kanamycin; (3) triply resistant, to low levels of viomycin, tuberactinomycin N and capreomycin; (4) triply resistant, to a low level of kanamycin and high levels of lividomycin and paromomycin; (5) quadruply resistant, to a low level of capreomycin and high levels of kanamycin, lividomycin and paromomycin; (6) hextuply resistant, to high levels of viomycin, tuberactinomycin N, capreomycin, kanamycin, lividomycin, and paromomycin. Three modificatied types of the latter were also observed. Appearance rates of the six types were estimated as 10(-6) to 10(-9), 10(-6), 10(-6) to 10(-7), 10(-8), 10(-8), and 10(-8) to 10(-9), respectively, in a total viable population of the parent strain. Mutations to all phenotypes were considered to be produced by single mutations. According to cross-resistance relationships, aminoglucoside antibiotics were classified into three groups: (I) streptomycin; (II) viomycin, tuberactinomycin N and capreomycin; (III) kanamycin, lividomycin and paromomycin. No cross-resistance relationship between streptomycin and other antibiotics was observed. Resistances to viomycin, tuberactinomycin N and capreomycin occurred by single mutation to type 3. Resistances to kanamycin, lividomycin and paromomycin occurred by single mutations to types 4 and 5. Low resistance to capreomycin was produced by mutation to type 5. Therefore capreomycin was considered to be an intermediate between the second and third groups. These two groups had a close relationship, as resistance to all six agents in these groups could be produced by a single mutation to type 6 (and its modified types).

Antibiotics, Antitubercular↗

[Therapeutic effect of lividomycin on infections of the respiratory tract (author's transl)].

Therapeutic effect of lividomycin was observed in patients with infections of the respiratory tract (infections in association with bronchiectasis, mixed infections of cavities after negative conversion of tubercle bacilli, pneumonia, and so forth). Significant improvement of clinical symptoms was observed in 15 cases and no improvement in 4 cases. Lividomycin was administered at a dose of 1 g/day for 3 to 15 days. Staphylococcus aureus (9 cases), Klebsiella pneumoniae (1 case), alpha-hemolytic Streptococcus (3 cases), Aerococcus (4 cases) and Pseudomonas aeruginosa (1 case) were suggested to be causative organisms in the above-mentioned patients. (In one case, however, causative organism was not determined.) Lividomycin seemed to be effective in cases of infections with Staphylococcus aureus, alpha-hemolytic Streptococcus and Klebsiella pneumoniae, whereas not effective in a case of infection with Pseudomonas aeruginosa. In order to differentiate causative organisms from the organisms constantly existing on the upper respiratory tract, alkali treatment was employed as an aid for the determination of the causative organisms. However, further studies are desirable for the evaluation of this procedure.

Adult↗