43405 Avoiding the Danger of Rising Resistance in Cutibacterium acnes: Criticality of Benzoyl Peroxide and Antibiotic Fixed Combinations
Recommended Citation
Ghannoum M, Gamal A, Kadry A, Del Rosso JQ, Bunick C, Stein Gold LF, Kircik L, Harper J. 43405 Avoiding the Danger of Rising Resistance in Cutibacterium acnes: Criticality of Benzoyl Peroxide and Antibiotic Fixed Combinations. J Am Acad Dermatol 2023; 89(3):AB20.
Document Type
Conference Proceeding
Publication Date
9-19-2023
Publication Title
J Am Acad Dermatol
Abstract
Antibiotic resistance is a global concern, with several countries reporting >50% of Cutibacterium acnes (C. acnes) strains as resistant to certain antibiotics [1,2]. Combination formulations with multiple antibiotics/antimicrobials may reduce the risk of resistance, especially with prolonged use [3,4]. This four-part study tested susceptibility of 31 C. acnes clinical strains to antibiotics alone or in combination with benzoyl peroxide (BPO). All antibiotics tested—clindamycin, doxycycline, erythromycin, and minocycline—had similar activity against most C. acnes strains tested, as assessed by minimum inhibitory concentration (MIC) ranges determined using epsilometer tests. Susceptibility was highly strain dependent, as some C. acnes strains had elevated MIC—an indication of resistance—against different antibiotics. C. acnes susceptibility to single-drug antibiotics and fixed-dose BPO combinations (branded/in-development) was then determined by measuring zone of inhibition using agar diffusion method, with larger diameter indicating increased bacterial inhibition. Interestingly, for 6 C. acnes strains that had no inhibitory zone with clindamycin alone, formulations with BPO enhanced activity against the same isolates (range: 0.8-2.2 cm with 3.1% BPO/1.2% clindamycin/0.15% adapalene, 5% BPO/1.2% clindamycin, or 3.75% BPO/1.2% clindamycin). Additional analyses are currently evaluating the potential synergistic effect of combining BPO and clindamycin and testing the development of C. acnes resistance following repeated bacterial growth exposed to a single antibiotic (clindamycin or minocycline) versus combinations with BPO. Overall, antibiotic susceptibility was highly strain dependent and antibiotic formulations with BPO exhibited enhanced activity against less susceptible C. acnes strains. Fixed combinations of BPO with an antibiotic may improve antimicrobial activity and protect against resistance development.
Volume
89
Issue
3
First Page
AB20
