SUSCEPTIBILITY OF PROPIONIBACTERIUM-ACNES, STAPHYLOCOCCUS-AUREUS AND STAPHYLOCOCCUS-EPIDERMIDIS TO 10 KAMPO FORMULATIONS

We examined the in vitro sensitivities of three bacteria: Propionibact erium acnes, and Staphylococcus epidermidis, commonly detected in acne lesions, and Staphylococcus aureus, a common cause of skin infections , to 10 Kampo formulations (Chinese herbal medicines; combinations of powdered extracts of crude drugs). Both Staphylococcus species showed similar sensitivities to all 10 formulations, with minimum inhibitory concentrations (MICs) ranging from 25 to 400 mg/ml. P. acnes, however, was particularly sensitive to one formulation, keigai-rengyo-to (MIC, 0.78 -25 mg/ml), prompting speculation that it might contain componen ts with strong antibacterial activity to P. acnes. P. acnes showed sim ilar sensitivities to all the other formulations (MIG 6.25 - 200 mg/ml ). The ranges of MICs and the MIC(50)s (concentrations that inhibit 50 % of isolates) were very similar to those previously recorded in 1990 for the two Staphylococcus species.