Effect of simethicone on the bactericidal efficacy of a high-level disinfectant

Area of Science:

• Microbiology
• Infection Control
• Medical Device Reprocessing

Background:

• Simethicone is commonly used in endoscopic procedures to improve visualization.
• Concerns exist that simethicone residue on endoscopes may compromise disinfection efficacy and increase infection risk.
• Limited direct evidence addresses the impact of simethicone on microbial risk during reprocessing.

Purpose of the Study:

• To evaluate the in vitro impact of simethicone on the efficacy of disinfectants.
• To determine if simethicone residue affects the bactericidal activity of disinfectants used for endoscopes.

Main Methods:

• Bacteria were cultured in microtitre plates with varying simethicone concentrations.
• Bacterial cultures were subsequently treated with a disinfectant (Cidex ortho-phthalaldehyde).
• Bacterial viability was assessed by agar plating to determine disinfectant efficacy.

Main Results:

• Simethicone did not reduce the efficacy of Cidex ortho-phthalaldehyde disinfectant.
• The disinfectant achieved at least a 6-log unit reduction in bacterial viability.
• High concentrations of simethicone (66 mg/ml) demonstrated direct bactericidal effects.

Conclusions:

• Simethicone does not appear to impair the bactericidal efficacy of ortho-phthalaldehyde disinfectant under tested conditions.
• The presence of simethicone residue may not increase microbial risk during endoscope reprocessing.
• Further research may be warranted to explore simethicone's interaction with other disinfectants and conditions.