INFLUENCE OF PRESERVATION TEMPERATURE AND PERIOD OF MEDIA USED FOR DRUG SENSITIVITY TEST ON MINIMAL INHIBITORY CONCENTRATION OF D-ETHAMBUTOL TO THE GROWTH OF MYCOBACTERIUM TUBERCULOSIS

• Published in: Kekkaku Vol. 44; no. 2; pp. 41 - 47
• Main Authors: TAMURA, Masatoshi, TAKANO, Satoshi
• Format: Journal Article
• Language: English; Japanese
• Published: Japan JAPANESE SOCIETY FOR TUBERCULOSIS 1969
• Subjects: Bacteriological Techniques; Culture Media; Depression, Chemical; Drug Resistance, Microbial; Ethambutol - pharmacology; Humans; Mycobacterium tuberculosis - drug effects; Mycobacterium tuberculosis - growth & development; Temperature; Time
• ISSN: 0022-9776; 1884-2410
• DOI: 10.11400/kekkaku1923.44.41

The influence of preservation temperature and period of media used for drug sensitivity test on the minimal inhibitory concentration of D-Ethambutol to the growth of Myco. tuberculosis was investigated. Media used were 1% Ogawa's egg slant and Kirchner's semi-liquid agar media with 10%. albumin. pH of the former was adjusted to 6.8 by suitable combination of 4% H2SO4 and 10%. Na3CO3, and pH of the basal media of the later was adjusted to 6.8. The concentration of D-Ethambutol added to the media was 0, 1, 2.5 and 10 mcg/ml. The media were dispensed into test tubes each 5 ml. Kirchner's semi-liquid agar media was used after being stored in an incubator at 37°C for 24 hours in order to confirm the sterility. After preparation, the media were stored at 5°C, 20°C, 30°C and 37°C for 1, 2, '3, 4, 6 and 8 weeks before their use. Strains used were 1187Rv and a strain isolated from sputa of a pulmonary tuberculosis. patient previously untreated with antituberculous drugs. Strains were planted on 1% Ogawa's egg slant before each experiment, and always 3 weeks culture was used for the experiment.10-3 mg of the strains were inoculated on each media stored at different temperature for 0 to 8 weeks. The results obtained were summarized as follows: 1) On both media, the minimal inhibitory concent r a tion of D-Ethambutol on the growth. of Myco. tuberculosis became slightly higher in accordance with the increase of preservation temperature and the prolongation of the preservation period. This effect was more marked on Kirchner's semi-liquid agar media than on 1% Ogawa's egg slant. 2) If the 3 weeks culture was inoculated on the medium immediately after preparation, the minimal inhibitory concentration of D-Ethambutol to the growth of Myco. tuberculosis was 2.5 mcg/ml on 1% Ogawa's egg slant and 5 mcg/ml in Kirchner's semi-liquid agar media.