Staphylococcus aureus and the oral cavity: an overlooked source of carriage and infection?

The role of intraoral Staphylococcus aureus in disease and cross-infection sources is controversial. We present a 10-year retrospective analysis of laboratory data reporting isolation of S aureus from oral and perioral clinical specimens.

A review of laboratory records for specimens where S aureus was isolated were collated and analyzed from January 1998-December 2007 at the Oral Microbiology Laboratory, Glasgow Dental Hospital.

There were 11,312 specimens submitted to the laboratory over the study time period. S aureus was isolated from 1,986 specimens (18%). Of these, 1,782 (90%) were methicillin-sensitive S aureus (MSSA), and 204 (10%) were methicillin-resistant S aureus (MRSA). The most common specimen type from which MSSA was isolated was an oral rinse, whereas for MRSA this was a tongue swab. Most of the MRSA isolates were EMRSA-15 or EMRSA-16 lineage.

These findings suggest that S aureus continues to be a frequent isolate in the oral cavity and perioral region. The oral cavity should be considered a source of S aureus in terms of cross-infection and dissemination to other body sites. The role of S aureus in the pathogenesis of certain oral diseases should also be considered as part of a differential diagnosis.