Correlation between levofloxacin consumption and the incidence of nosocomial infections due to fluoroquinolone-resistant Escherichia coli

Background/purpose: The relationship between fluoroquinolone resistance in Escherichia coli isolates causing nosocomial infection and hospital antibiotic consumption were investigated. Restriction of levofloxacin use was implemented to control the incidence of fluoroquinolone-resistant E coli in the hospital. Methods: The study was conducted from January 2004 to December 2010. Antimicrobial agent consumption was obtained from the pharmacy computer system and presented as the defined daily doses per 1000 patient-days every 6 months. The incidence of fluoroquinolone-resistant E coli isolates causing nosocomial infections was obtained from the Department of Infection Control every 6 months. An antimicrobial stewardship program, restricting levofloxacain use, was implemented in July 2007. Results: The incidence of fluoroquinolone-resistant E coli causing nosocomial infections was significantly correlated with fluoroquinolone usage (p = 0.005), but not with the use of third- or fourth-generation cephalosporins, piperacillin-tazobactam, or carbapenems. Parenteral (p = 0.002), oral (p = 0.018), and total levofloxacin (p = 0.001) use were significantly correlated with the extent of fluoroquinolone resistance. With a reduction of levofloxacin use, a decrease of the incidence of fluoroquinolone resistance in E coli isolates was observed. Conclusion: There is a significant correlation between levofloxacin use and the incidence of nosocomial fluoroquinolone-resistant E coli isolates. The incidence of fluoroquinolone-resistant E coli could be reduced by limiting levofloxacin consumption. Copyright (C) 2011, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.