Cutibacterium acnes of single locus sequence type clade C strains exhibit low susceptibility to benzoyl peroxide.

BACKGROUND

Cutibacterium acnes plays an important role in acne pathogenesis. Benzoyl peroxide (BPO) exhibits antimicrobial activity against C. acnes. We previously found that no clade C strains, as determined by single locus sequence typing (SLST), were found before the introduction of BPO in Japan. However, the prevalence of clade C strains increased after its introduction. In this study, we evaluated the susceptibility of C. acnes strains, belonging to different SLST clades, to BPO.

METHODS

Forty clinical C. acnes isolates from four distinct SLST clades obtained from acne lesions were analyzed. The susceptibility of C. acnes isolates to BPO was evaluated using a time-kill kinetic assay.

RESULTS

C. acnes clade C strains were less susceptible to BPO. In addition, the bactericidal effect of BPO was time-dependent across all clade strains.

CONCLUSIONS

An increase in C. acnes clade C strains may diminish the efficacy of acne treatment. Therefore, the trends in the prevalence of C. acnes clade C strains should be monitored.