An in Vitro Experimental Study on the Antimicrobial Activity of Silicone Oil against Anaerobic Bacteria

Abstract

Purpose: To investigate the in vitro antimicrobial activity of silicone oil against anaerobic agents, specifically Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium.

Method: A 0.5 McFarland turbidity of Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium was prepared, and 0.1 mL was inoculated into 0.9 mL of silicone oil. Control inoculations were performed in anaerobic blood agar and fluid thioglycollate medium without silicone oil.

Results: Propionibacterium acnes retained their viability on the 3rd day in the presence of silicone oil. In total, 9.7 × 10⁶ colonies were enumerated from 1 mL of silicone oil. After a prolonged incubation of 7 days, the number of colonies observed was 9.2 × 10⁶. The other bacteria disappeared after the 3rd day of incubation in silicone oil.

Conclusions: Propionibacterium acnes, which is the most common chronic postoperative endophthalmitis agent, is thought to be resistant to silicone oil.

• Anaerobic bacteria
• antimicrobial resistance
• antimicrobial susceptibility
• endophthalmitis
• silicone oil

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.