Multidrug Resistance Plasmid pTZC1 Could Be Pooled among Strains on the Skin Surface.

Acne vulgaris is a chronic inflammatory skin disease that is exacerbated by Cutibacterium acnes. Although antimicrobials such as macrolides, clindamycin, and tetracyclines are used to treat acne caused by , the increasing prevalence of antimicrobial-resistant strains has become a global concern. In this study, we investigated the mechanism by which interspecies transfer of multidrug-resistant genes can lead to antimicrobial resistance. Specifically, the transfer of pTZC1 between and isolated from specimens of patients with acne was investigated. Among the and isolated from 10 patients with acne vulgaris, 60.0% and 70.0% of the isolates showed resistance to macrolides and clindamycin, respectively. The multidrug resistance plasmid pTZC1, which codes for macrolide-clindamycin resistance gene (50) and tetracycline resistance gene (W), was identified in both and isolated from the same patient. In addition, whole-genome sequencing revealed that the pTZC1 sequences of and showed 100% identity using comparative whole-genome sequencing analysis. Therefore, we hypothesize that the horizontal transfer of pTZC1 between and strains may occur on the skin surface. The plasmid transfer test revealed a bidirectional transfer of pTZC1 between and , and transconjugants that obtained pTZC1 exhibited multidrug resistance. In conclusion, our results revealed that the multidrug resistance plasmid pTZC1 could be transferred between and . Furthermore, since pTZC1 transfer among different species may aid in the prevalence of multidrug resistant strains, antimicrobial resistance genes may have been pooled on the skin surface. The emergence of antimicrobial resistance not only in Cutibacterium acnes strain but also other skin bacteria such as Staphylococcus epidermidis is a big concern due to antimicrobial use for the treatment of acne vulgaris. Increased prevalence of macrolides-clindamycin resistant relates to the acquisition of exogenous antimicrobial resistance genes. (50) is harbored by the multidrug resistance plasmid pTZC1, which has been found in and strains isolated from patients with acne vulgaris. In this study, and with pTZC1 were found in the same patient, and plasmid transfer between and was proved by transconjugation assay. This study showed plasmid transfer between other species and the possibility of further prevalence antimicrobial resistance between species.