KIRCHNER FJ, FITZGIBBON JE, ALCID DV, JOHN JF; Interscience Conference on Antimicrobial Agents and Chemotherapy (42nd : 2002 : San Diego, Calif.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2002 Sep 27-30; 42: abstract no. C2-1126.
UMDNJ-Robert Wood Johnson, New Brunswick, NJ
BACKGROUND: The goal of this study was to determine whether a formulary switch from levofloxacin (LVX) to gatifloxacin (GTX) would affect fluoroquinolone susceptibility of MRSA isolates. METHODS: A total of 123 MRSA isolates were collected, 54 during the period of LVX usage and 69 during the period of GTX usage. All isolates were subjected to both disk diffusion testing and broth microdilution testing with the fluoroquinolone agents ciprofloxacin (CIP) and LVX. Disk diffusion results were classified as either susceptible or non-susceptible. Broth microdilution results yielded minimum inhibitory concentration values (MICs) for each isolate. Disk diffusion results were compared using the chi square test; broth microdilution results were compared using the Mann-Whitney U test. RESULTS: Disk diffusion results demonstrated a significantly higher proportion of CIP and LVX susceptible isolates after the formulary switch to GTX. Thirteen percent of the isolates were susceptible to CIP before the switch vs. 28% after the switch (p=0.0495). Thirteen percent were susceptible to LVX before the switch vs. 32% after the switch (p=0.0142). Broth microdilution results also showed significantly lower MIC values for CIP after the switch to GTX (p=0.0192), but the difference was not significant for LVX. CONCLUSIONS: MRSA isolates obtained after a formulary switch from LVX to GTX were more likely to be susceptible to CIP and LVX. Additional studies are needed to confirm these results and to determine the cause of the increase in fluoroquinolone-susceptible MRSA.
Publication Types:
Keywords:
- Ciprofloxacin
- Fluoroquinolones
- Microbial Sensitivity Tests
- Ofloxacin
- Staphylococcus aureus
- gatifloxacin
Other ID:
UI: 102268211
From Meeting Abstracts