Oligochitosan as a potential anti-acne vulgaris agent: combined antibacterial effects against .

To develop an antibacterial treatment for acne vulgaris using natural substance with few side effects, we investigated the antibacterial activities of oligochitosan against acne-related bacteria, particularly . Oligochitosan showed potent antibacterial effect on . Especially, 10 kDa oligochitosan presented the highest antimicrobial effect with minimum inhibitory concentration values of 32-64 μg/mL on . In addition, oligochitosan clearly reversed the antibacterial effect of tetracycline and erythromycin on in the combination mode. The combination of tetracycline- or erythromycine-10 kDa oligochitosan resulted in a median ΣFIC range of 0.02-0.56, suggesting that the antibiotics-oligochitosan combination resulted in an antibacterial synergy against . Thus, the results obtained in this research strongly supported that erythromycin and tetracycline will restore the antibacterial activity against in the combination mode with 10 kDa oligochitosan.