Determination of microbial agents of acne vulgaris and Propionibacterium acnes antibiotic resistance in patients referred to dermatology clinics in Kerman, Iran

Introduction and objective: Acne is the most common skin disorder with a very high prevalence. Antibiotics have been used for more than 40 years against Propionibacterium acnes, the most common agent of acne. Antibiotic resistance of this bacterium was first reported in 1979, but became a worldwide problem in the recent years. The aim of this study was to determine the prevalence of antibiotic resistance among P. acnes isolates from acne patients referred to the dermatology clinics in Kerman, Iran during 2008-2009. Materials and methods: The samples were obtained from face and trunk lesions of 100 acne patients by a sterile swab and then inserted into a transport medium in which they were inoculated into two blood agar plates. One was incubated aerobically at 37°C for 24h and another one in anaerobic conditions at 37°C for one week. P. acnes was isolated, identified and antibiotic susceptibility of each isolate was determined by disk diffusion method. Results: Viable propionibacteria were detected in 57 patients. Thirty one percent of P. acnes isolates were resistant at least to one antibiotic. No resistance was seen to azithromycin and doxycycline. Lowest sensitivity was to clindamycin. Erythromycin resistance was low. No significant difference was detected in antibiotic resistance in the patients with and without treatment history and also no relationship was observed between P. acnes resistance and different body sites. Conclusion: P. acnes resistance to current antibiotics is a common problem and selection of appropriate antibiotics in order to decrease treatment failure and sequels of acne is an important issue.