Studies on Non-Pathogenic Acid-Fast Bacilli

The acid-fast bacilli were examined for the capacity of utilizing carbohydrates and organic acids as the carbon sources and sensitivity for antibiotics. The results obtained are asfollows.1. In general, most of the saprophytic strains were capable of utilizing more kinds of carbohydrates as carbon sources than the human or animal strains. The capacity ofutilizing carbohydrates, however, was of little value as criterion in classifying these acid-fast bacilli. Of the substances examined, monosaccharides and and sugar alcohol were utilized by most of the acid-fast strains as carbon sources. On the contrary, disaccharides and organic acids were utilized by only a few of the strains.2. Oxalate was utilized as carbon source only by a type of Mycobacterium smegmatis which is define as an organisms growing at 47°C and failing to survive heating at 60°C for one hour.3. Of 72 strains examined, all were resistant to 100γper ml of para-aminosalicylic acid and 66 to 100γper ml of isoniazed. Colored strains were more sensitive for streptomycin than colorless strains. There was a tendency that the strains which were intermediate betweenthe smooth and the rough type in colonial morphology were strongly resistant to streptomycin.