A “Hail-Mary” Oral Antimicrobial Strategy for a Complex Case of Persistent MRSA Bacteremia

Persistent bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA) has a high mortality rate. While combination parenteral antibiotic regimens have shortened duration of bacteremia in some trials, they were also associated with increased nephrotoxicity and did not improve clinical outcomes. We cared for a patient with MRSA bacteremia that persisted for nearly 3 weeks. Due to medical ethical complexities, intravenous therapy could not be administered after day 6, so oral linezolid was started. On day 20 of persistent bacteremia, we attempted a “hail Mary” intensification by adding oral moxifloxacin and rifampin. On day 21, blood cultures cleared. Causality from the intensification cannot be presumed, but the temporal association was intriguing. Nevertheless, an oral regimen successfully cleared persistent S. aureus bacteremia, calling into question the necessity to wait until clearance of bacteremia before initiation of oral therapy. These results support the future study of all-oral therapy for S. aureus bacteremia.