Related Experiment Video
Updated: May 13, 2026

Concurrent Quantification of Cellular and Extracellular Components of Biofilms
Published on: December 10, 2013
Commercial mouthwashes are ineffective against oral MRSA biofilms
Karen Smith1, Douglas P Robertson, David F Lappin
1Institute of Healthcare Associated Infection, University of the West of Scotland, Ayr, UK.
Objective:
The aim of this study was to evaluate and compare the activity of oral mouthwashes against biofilm forms of MRSA isolated from the oral cavity and the bloodstream.
Study Design:
The time-kill kinetics efficacy of 7 over-the-counter mouthwashes were tested against 28 clinical MRSA biofilm isolates for 0.5, 1 and 2 min.
Results:
Treatments of MRSA biofilms formed by oral and bloodstream isolates were not significantly different, with mouthwashes displaying a rapid and modest anti-biofilm effect. None of the biofilm isolates were completely eradicated by the compounds tested, with a maximal killing of only approximately 70% shown by Corsodyl and Peroxyl. Maximum activity of all compounds tested was observed after 0.5 min. Fluorigard showed the poorest overall activity (57% reduction).
Conclusions:
MRSA colonize the oral cavity, and are more prevalent in institutionalized persons and the elderly. Over-the-counter mouthwashes are ineffective at killing MRSA biofilms, which has infection control implications.
More Related Videos
Related Concept Videos
Clinical Significance of Antibiotic Resistance
Mechanism of Antibiotic Resistance in MRSA
The Oral Microbiota
Biofilms
Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
Antimicrobial Effectiveness

