Resistance of Propionibacterium acnes and Staphylococcus epidermidis acnesto cycline

Background: A rising percentage of tetracycline-resistant Propionibacterium acnes strains has been reported in the English literature. Patients and methods: We studied a population of 16 patients with acne who had been treated with oral tetracyclines during the preceding year. A bacte riological examination of a skin biopsy was obtained in all patients to det ermine aerobic and anaerobic flora as wells as resistance to tetracycline a nd minocycline. Results: Staphylococcus epidermidis strains were frequently resistant to te tracycline (87.5 %) as well as minocycline (30 %). Tetracycline-resistant P ropionibacterium acnes were also observed (7 %). Inversely, we were unable to evidence any minocycline-resistant Propionibacterium acnes strains. Conclusion: These findings emphasize the importance of determining whether therapeutic response is related or not to the presence of resistant strains .