Emerging antimicrobial resistance among Cutibacterium acnes isolated from inflammatory acne vulgaris patients

Acne vulgaris, a common skin disorder, primarily affects adolescents and often results in both inflammatory and noninflammatory lesions. Cutibacterium acnes (C. acnes) plays a central role in the pathogenesis, and the emergence of antimicrobial resistance (AMR) in C. acnes poses a significant challenge in acne treatment.

This study aims to assess the AMR trends of C. acnes isolates from acne vulgaris patients for commonly used antimicrobial agents.

Setting: Tertiary care teaching hospital in Central India. Design: Observational cross-sectional study.

A total of 109 patients with pustular acne vulgaris were recruited over 15 months. Skin swabs were collected from lesions, cultured on Propionibacterium Isolation agar, and identified by conventional microbiological methods. Antimicrobial susceptibility testing (AST) was conducted using the Epsilometer test (E-test) to assess the AMR trends to clindamycin, erythromycin, doxycycline, and azithromycin.

C. acnes was isolated from 29.35% of acne cases. Most of the acne vulgaris cases belonged to 18-25 years of age (77.98%) and were male patients (62.38%). Resistance to two or more classes of antibiotics was observed in 25% of isolates. Maximum resistance was observed for macrolide groups of antimicrobial agents, that is, erythromycin and azithromycin, while doxycycline (93.7%) and clindamycin (81.2%) exhibited good susceptibility.

This study highlights a significant concern regarding AMR in C. acnes, particularly to macrolides. Judicious use of antibiotics and adopting non-antibiotic treatments, such as retinoids and benzoyl peroxide, are crucial to mitigate the growing resistance issue and improve acne management.