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 bacteriological examination of a skin biopsy was obtained in all patients to determine aerobic and anaerobic flora as wells as resistance to tetracycline and minocycline.
Results: Staphylococcus epidermidis strains were frequently resistant to tetracycline (87.5%) as well as minocycline (30%). Tetracycline-resistant Propionibacterium 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.