Author/Authors :
Khasawneh, Faisal A. King Hussein Cancer Center - Department of Internal Medicine, Jordan , Khasawneh, Faisal A. Tulane Health Sciences Center, USA , Ashcraft, Deborah S. Ochsner Clinic Foundation - Infectious Disease Laboratory, USA , Pankey, George A. Ochsner Clinic Foundation - Infectious Disease Laboratory, USA
Abstract :
Objectives: To test for synergy between daptomycin (DAP) and rifampin (RIF) against RIF-resistant methicillin-resistant Staphylococcus aureus (MRSA) isolates.Methods: Synergy testing using time-kill assay (TKA) was performed on 6 clinically, and genetically unique RIF-resistant MRSA isolates. The isolates were identified out of 489 (1.2%) samples collected during April 2003 to August 2006, from patients at the Ochsner Medical Center in New Orleans, Louisiana, United States of America.Results: Synergy testing of DAP plus RIF by TKA showed that 5 isolates were indifferent, but one isolate was antagonistic.Conclusion: Our in vitro study failed to demonstrate synergy between DAP plus RIF, against our RIF-resistant MRSA isolates. Clinical failure of this combination should prompt the clinician to consider antagonism, as one of the potential causes
