In vitro testing of daptomycin plus rifampin against methicillin-resistant Staphylococcus aureus resistant to rifampin

Authors

• Faisal A. Khasawneh, Department of Internal Medicine, King Hussein Cancer Center, Amman, Jordan, and formerly of Tulane Health Sciences Center, New Orleans, Louisiana, United States of America.
• Deborah S. Ashcraft, Department of Internal Medicine, King Hussein Cancer Center, Amman, Jordan, and formerly of Tulane Health Sciences Center, New Orleans, Louisiana, United States of America.
• George A. Pankey, Department of Internal Medicine, King Hussein Cancer Center, Amman, Jordan, and formerly of Tulane Health Sciences Center, New Orleans, Louisiana, United States of America.

Abstract

OBJECTIVE: 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.

Article Type

Research Article

First Page

1726

Last Page

1729

Recommended Citation

Khasawneh, Faisal A.; Ashcraft, Deborah S.; and Pankey, George A. (2008) "In vitro testing of daptomycin plus rifampin against methicillin-resistant Staphylococcus aureus resistant to rifampin," Saudi Medical Journal: Vol. 29: Iss. 12, Article 6.
DOI: https://doi.org/10.15537/1658-3175.4561