Ocular Propionibacterium Acnes: A Study On Antibiotic Susceptibility Profiling And Their Epidemiological Pattern

Purpose: To identify the antibiotic pattern of commonly used P. acnes isolates and to analyse the epidemiological patterns using Random Amplification of Polymorphic DNA (RAPD) technique. Methods: One hundred P. acnes isolates (90 % extraocular and 10% intraocular) recovered from ocular clinical specimens identified by conventional method were studied. MIC of ciprofloxacin, norfloxacin, nalidixic acid, clindamycin, penicillin G, vancomycin and metronidazole, cefotaxime and imepenum were carried out for 100 P. acnes ophthalmic isolates by spot inoculation technique. Results: Six distinct RAPD patterns were observed among these isolates of which the 4 pattern was the most predominant one (41%), which was isolated mostly from conjunctival swabs. Of the 100 clinical anaerobic P. acnes isolates, highest resistant antibiotic pattern was seen among conjunctival swabs isolates for metronidazole (100%). Following it was the clindamycin (79%) and penicillin G (64%). Conclusion: This study has proven that RAPD is a reproducible, powerful technique for P. acnes genomic typing and may definitely play a vital role in identifying epidemiology of P. acnes. There was no correlation between the antibiotic pattern and the corresponding RAPD fingerprinting results in our study. Resistance to Vancomycin, the most commonly used intravitreal antibiotic is emerging among P. acnes is being reported for the first time. Studies at molecular level with vancomycin resistant isolates will help to understand the mechanism of resistance.