Abstract
A bacterial culture (No. 24 strain) belonging to the genusBacilluswas isolated from the contaminants of a cataplasm. Based on morphological and biochemical characteristics, No. 24 strain was considered to be identical toBacillus circulans.Bacillus circulansis closely related toB. macerans. The principal differential characteristic betweenB. circulansandB. maceransis known to be gas formation from glucose. Generally, B. maceransproduces both acid and gas, butB, circulansproduces acid only. However, B. maceransIFO 3490, used as a reference strain in this study, showed no gaseous formation. Then, the susceptibility ofB. maceransandB. circulansto various antibiotics was tested. It was found thatB. maceransIFO 3490 was resistant to macrolides (especially erythromycin), the minimum inhibitory concentration (MIC) of erythromycin being 50 μg/ml. On the contrary, both No. 24 strain andB. circulansIFO 3329 were sensitive to erythromycin (MIC : 0.1-0.2 μg/ ml) . It was suggested that the application of a sensitivity test to erythromycin might be useful for the differentiation ofB. circulansfromB. macerans.
