Antibiotic resistance and biofilm formation in Cutibacterium acnes: A descriptive cross-sectional study.

Background The issue of antibiotic resistance in acne vulgaris has emerged as a significant concern in recent times. Though the ability of Cutibacterium acnes to form biofilms have been established, its role in acne vulgaris has yet to be ascertained. Aims This descriptive cross-sectional study was aimed to investigate the ability of C. acnes to form biofilms and its potential association with resistance to the commonly used antibiotics. Methods A total of 88 patients with acne vulgaris were selected for this study. Clinical examination and severity grading was done. The collected samples were analysed with Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) and further subjected to biofilm testing using the microtiter plate assay. Results C. acnes were isolated from 43.1 of the samples (n = 38). The highest resistance was observed with azithromycin (73.7%) followed by clindamycin (65.8%), doxycycline (15.8%), ampicillin (31.6%) and minocycline (5.3%). Thirty-seven per cent of the isolates were resistant to at least two antibiotics, 63.2% of C. acnes had a weak capacity to form biofilms and more than 60 percent of the isolates showed resistance to atleast two types of antibiotics as well as weak biofilm forming capacity. Limitations Single-centre study, small sample, long-term follow-up of the patients was not done. In addition, this study is representative of only C. acnes species. Conclusion While C. acnes have the ability to create biofilms, its effectiveness in antibiotic resistance can be deemed as modest based on the findings of this study. It is important to consider alternative mechanisms such as genetic or biochemical plasticity that may contribute to antibiotic resistance.