Faisal A Khasawneh1, Deborah S Ashcraft, George A Pankey. 1. 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.
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.
Authors: J M Miró; C García-de-la-Mària; Y Armero; D Soy; A Moreno; A del Río; M Almela; M Sarasa; C A Mestres; J M Gatell; M T Jiménez de Anta; F Marco Journal: Antimicrob Agents Chemother Date: 2009-07-20 Impact factor: 5.191