Methicillin-resistant Staphylococcus aureus and Candida albicans on denture surfaces

Area of Science:

• Microbiology
• Oral Health
• Infectious Diseases

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans are significant pathogens, particularly in immunocompromised individuals.
• Denture use is common, and these microorganisms can colonize denture surfaces and oral cavities.

Purpose of the Study:

• To quantify MRSA and Candida albicans on dentures and in saliva.
• To investigate the adherence of these microbes to surfaces and interactions with oral bacteria.
• To assess the efficacy of denture cleaners in reducing microbial load.

Main Methods:

• Enumeration of MRSA and Candida albicans on denture surfaces and in saliva from 29 adults.
• In vitro adherence assays using resin beads and saliva-coated resin beads.
• Characterization of microbial hydrophobicity and zeta potential.
• Assessment of interactions with oral bacteria, including growth inhibition and co-aggregation.

Main Results:

• MRSA and Candida albicans were frequently detected on dentures and in corresponding saliva samples.
• Both microorganisms adhered significantly more to saliva-coated surfaces.
• Oral bacteria showed some inhibitory effects on MRSA, but not Candida albicans.
• Standard denture cleaners were ineffective in reducing microbial counts in saliva.

Conclusions:

• Denture surfaces serve as reservoirs for MRSA and Candida albicans, with implications for infection risk.
• Saliva coating enhances microbial adherence to surfaces.
• Interactions with oral microbiota may influence MRSA colonization.
• Current denture cleaning practices are insufficient to eliminate these pathogens from saliva.