Oral carriage of staphylococci in patients with rheumatoid arthritis.

OBJECTIVE To determine the prevalence of oral staphylococcal carriage in patients with rheumatoid arthritis compared with healthy controls. METHODS Fifty healthy adults, 25 healthy elderly volunteers and 25 patients with rheumatoid arthritis were studied. An oral rinse, tongue swab and nasal swab were collected for culture on blood agar and a range of selective agars. Isolates of staphylococci were identified and antibiotic sensitivity profiles determined by standard methods. RESULTS Staphylococci were isolated from the mouths of 94% of the healthy adults, 24% of whom carried Staphylococcus aureus. All the healthy elderly carried oral staphylococci and 36% were colonized with S. aureus. Staphylococci were isolated from 96% of the rheumatoid arthritis patients and this group had the highest carriage rate of S. aureus (56%), significantly higher than the healthy adults (P < 0.05). In all three groups, Staphylococcus epidermidis was isolated from the mouths of > 80%. No methicillin-resistant strains of S. aureus were isolated. CONCLUSION Oral carriage of S. aureus appears to be common in patients with rheumatoid arthritis and studies of the mouth as a source of infection in septic arthritis would be merited.