Modelling vaporised hydrogen peroxide efficacy against mono-species biofilms

Area of Science:

• Microbiology
• Infectious Diseases
• Environmental Health

Background:

• Contaminated surfaces in healthcare settings are a major route for pathogen transmission.
• Pathogens can form resilient biofilms on surfaces, evading standard cleaning protocols.
• Multidrug-resistant organisms (MDROs) pose a significant threat in hospitals.

Purpose of the Study:

• To investigate the efficacy of hydrogen peroxide vapor (HPV) against MDRO biofilms.
• To develop and validate a novel methodology for testing antimicrobial agents against biofilms.
• To identify potential resistance mechanisms in MDROs exposed to HPV.

Main Methods:

• Biofilm models of MDROs (Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus) were generated using a drip flow reactor.
• Biofilms were exposed to HPV decontamination, with samples collected periodically for enumeration.
• Kill curves were generated to assess the reduction of viable organisms.
• Epifluorescence microscopy was used to visualize viable and non-viable microcolonies.

Main Results:

• HPV achieved a greater than 6-Log10 reduction of MDROs within 100 minutes.
• Catalase-producing organisms showed reduced susceptibility, indicating potential resistance mechanisms.
• Epifluorescence microscopy confirmed the presence of both viable and non-viable microcolonies post-treatment.

Conclusions:

• HPV is an effective decontamination agent against MDRO biofilms.
• The study proposes a viable methodology for assessing antimicrobial efficacy against biofilms.
• Understanding biofilm resilience is crucial for effective infection control in healthcare environments.