title: Oral staphylococcus in older subjects with rheumatoid arthritis.
abstract: OBJECTIVE
  To determine if Staphylococcus aureus and Staphylococcus epidermidis, etiologic bacterial agents to late prosthetic joint infections (LPJI), are more prevalent in the oral flora of older individuals with rheumatoid arthritis (RA) than in an age and gender-matched nonarthritic control population (NA).
  
  
  METHODS
  Cultures were obtained from the nares, oropharynx, saliva, tongue, and gingival crevice, and the results were compared between older patients with RA and controls.
  
  
  METHODS
  University of Michigan Medical Center, Ann Arbor, VA Medical Center, and University of Michigan School of Dentistry.
  
  
  METHODS
  A total of 111 community-dwelling subjects with a diagnosis of RA and 83 gender-matched control subjects.
  
  
  METHODS
  Colistin nalidixic acid agar plates with 5% sheep's blood were inoculated and incubated. Isolates were speciated using the API Staph Trac micro method and catalase and coagulase tests.
  
  
  RESULTS
  Individuals with RA had a higher prevalence of S. aureus isolated from the oral cavity. However, only the oropharynx and tongue revealed higher rates; all other sites were insignificant. The presence of oral S. aureus was associated with xerostomia. Staphylococcus epidermidis was not detected from any of the oral sites sampled. Sixty-two percent (10/16) of the S. aureus isolates from the RA subjects were resistant to penicillin and ampicillin, whereas none were resistant to a cephalosporin.
  
  
  CONCLUSIONS
  These findings suggest that rheumatoid arthritis may be a risk factor for LPJI in older prosthetic joint patients undergoing invasive dental procedure in the posterior oral cavity. This increased risk is caused, in part, by a higher prevalence of S. aureus in the posterior oral cavity. The prevalence and the antibiotic resistance of S. aureus must be considered when determining the need for chemoprophylaxis.
authors.affiliation: University of Michigan School of Dentistry.
authors.forename: J J
authors.initials: JJ
authors.lastname: Jacobson
authors.forename: B
authors.initials: B
authors.lastname: Patel
authors.forename: G
authors.initials: G
authors.lastname: Asher
authors.forename: J O
authors.initials: JO
authors.lastname: Woolliscroft
authors.forename: D
authors.initials: D
authors.lastname: Schaberg
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009059:Mouth Diseases / Q000150:complications / Q000382:microbiology*; D015995:Prevalence; D013203:Staphylococcal Infections / Q000150:complications* / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D013212:Staphylococcus epidermidis / Q000302:isolation & purification*