211. Decreased resistance of Pseudomonas aeruginosa with restriction of ciprofloxacin in a large teaching hospitalís intensive and intermediate care units.
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
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  • Background: Gram-negative resistance in high antimicrobial use units, such as intensive and intermediate care units, is a growing concern. We examined the effect of restricting ciprofloxacin use on the resistance of nosocomial gram-negative bacilli, including Pseudomonas aeruginosa, to group 2 carbapenems (imipenem, meropenem and doripenem) in intensive and intermediate care units.

    Methods: The study was conducted January 1, 2004 through December 31, 2010 in a large teaching hospital with 11 intensive and intermediate care units totaling 295 beds. Ciprofloxacin use was restricted in July 2007. Interrupted time series analysis was used to compare rates of resistant isolates per 10,000 patient days and percentage of resistant isolates to group 2 carbapenems, ciprofloxacin, piperacillin-tazobactam (PipTazo) and cefepime before and after the restriction. Linear regression was used to determine trends in yearly antibiotic use defined as Defined Daily Dose/1,000 patient days.

    Results: There was a decreasing trend in the percentage (p = 0.0351) and rate (p = 0.0006) of P.aeruginosa resistant to group 2 carbapenems following the restriction of ciprofloxacin. There was also a decreasing trend in the percentage (p = 0.0017) and rate (p = 0.001) of P.aeruginosa resistant to ciprofloxacin. The rate of cefepime resistant P.aeruginosa isolates declined (p = 0.004), but the percentage of cefepime resistant P.aeruginosa did not. There were no significant changes in the rate or percentage of PipTazo resistant P.aeruginosa isolates. There were no significant changes in susceptibilities of nosocomial Enterobacteriaciae or Acinetobacter baumannii isolates to carbapenems. Over the study period, there was a significant increasing trend in the use of carbapenems (p = 0.0134); the use of ciprofloxacin significantly decreased (p = 0.0027). There were no significant changes in the use of PipTazo or cefepime.

    Conclusion: Restriction of ciprofloxacin was associated with a decreased resistance of P.aeruginosa to ciprofloxacin and group 2 carbapenems in our hospital’s intermediate and intensive care units. There were no changes in the susceptibilities of nosocomial Enterobacteriaciae or Acinetobacter baumannii to carbapenems despite an increase in carbapenem use.

    Subject Category: A. Antimicrobial agents and Resistance

    Gus Jonathan Lewis, DO, MPH1, Xiangming Fang, PhD1, Mike Gooch, MS Pharm2 and Paul Cook, MD1, (1)East Carolina University, Greenville, NC, (2)Division of Infectious Disease, East Carolina University, Greenville, NC


    G. J. Lewis, None

    X. Fang, None

    M. Gooch, None

    P. Cook, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.