Difficulty in removing biofilm from dry surfaces

Area of Science:

• Microbiology
• Infection Control
• Biomaterials

Background:

• Effective cleaning is crucial for preventing healthcare-associated infections.
• Staphylococcus aureus is a common pathogen, often forming resilient biofilms.
• Biofilm formation significantly increases bacterial resistance to antimicrobial agents and physical removal.

Purpose of the Study:

• To compare the efficacy of a standardized wiping process in removing Staphylococcus aureus biofilms versus dried planktonic bacteria.
• To quantify the number of wiping actions required to achieve significant reduction of both bacterial states.

Main Methods:

• A standardized wiping process was applied to surfaces contaminated with Staphylococcus aureus.
• Surfaces were contaminated with either dried planktonic bacteria or mature bacterial biofilms.
• Bacterial reduction was quantified using colony-forming unit counts after a defined number of wiping actions.

Main Results:

• A single wiping action removed over 99.9% (>3 log10) of dried planktonic Staphylococcus aureus.
• Fifty wiping actions removed only 1.4 log10 (96.66%) of Staphylococcus aureus biofilm.
• Biofilm removal was significantly less efficient compared to the removal of planktonic bacteria.

Conclusions:

• Staphylococcus aureus biofilms present a substantially greater challenge for removal compared to dried planktonic bacteria.
• Standard cleaning protocols may be insufficient for eradicating established bacterial biofilms.
• Further research into effective biofilm decontamination strategies is warranted for improved infection control.