Attempts to eradicate methicillin-resistant Staphylococcus aureus colonization with the use of trimethoprim-sulfamethoxazole, rifampin, and bacitracin.

Retrospective review of 197 patients with methicillin-resistant Staphylococcus aureus (MRSA) identified 47 in whom a regimen for eradication of MRSA colonization could be evaluated. The patients were elderly (mean age, 67.7 years), with 53% transferred from another institution and 53% treated in an intensive care unit. A mean of 47.1 days of hospitalization with an average of 4.9 antibiotics preceded the first MRSA culture. The usual regimen (mean, 6.0 days) was oral trimethoprim-sulfamethoxazole, 160/800 mg twice daily, oral rifampin, 600 mg once daily, and bacitracin ointment three times a day. Eradication succeeded in 40 patients, 9 relapsed, and MRSA persisted in 7. Twenty-four of 25 nares sites were cleared but only 16 of 22 other sites. MRSA infection eventually developed in 36%. No adverse reactions to the eradication regimen were noted. Although this treatment for MRSA carriage was safe and effective, decreased efficacy outside the nares and relapse limited its value.