Cutibacterium acnes (C. acnes ) – an emerging pathogen that is highly resistant to antibiotics, is capable of causing persistent infections that are difficult to treat.

A new study published in the Journal of Laboratory Physicians was to identify antibiotics effective in treating acne vulgaris caused by C. acnes.

The present study recruited acne vulgaris patients visiting dermatology OPD of a hospital during the study period of two months. Skin swabs were collected and isolates were identified by the standard biochemical test. Antimicrobial susceptibility testing was performed for clinically relevant antibiotics; clinical response was evaluated after 1month follow-up to the prescribed antibiotics.

The results indicated that minocycline, doxycycline, ceftriaxoneand tetracycline were the most effective antibiotics. Nonsusceptibility to clindamycin and erythromycin were observed in 11.9% and 31% isolates, respectively—with 9.5% isolates being nonsusceptible to both. A significant difference in the proportion of susceptible and nonsusceptible isolates between mild, moderate and severe grades of acne vulgaris were not found for any of the antibiotics. In addition, for any of the antibiotic regimens, marked difference was not observed between nonresponders and responders. Twenty-seven patients received clindamycin and among them 16 of 19 responders and 6 of 8 nonresponders yielded growth of clindamycin-susceptible isolates.

Therefore, significant prevalence of resistant strains of C. acnes was depicted among patients with acne vulgaris. However, no association was elicited between in vitro susceptibility results and treatment outcome.

Source: Journal of Laboratory Physicians. 2020 Dec;12(4):233-238.doi: 10.1055/s-0040-1720943.