Program Schedule

Impact of Fluoroquinolone Resistance on Community-Onset Gram-Negative Bloodstream Infections

Session: Poster Abstract Session: Bacteremia: Gram-Negative Bacteremia
Friday, October 10, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • 715_IDWPOSTER.pdf (707.1 kB)
  • Background:

    There has been a disconcerting increase in fluoroquinolone resistance (FQ-R) rates among gram-negative bloodstream isolates. FQ-R isolates are often resistant to other antimicrobial agents, limiting options for intravenous to oral switch. This retrospective cohort study examines the hypothesis that FQ-R is associated with longer hospitalization in patients with gram-negative bloodstream infections (BSI).


    Hospitalized adults with first episodes of community-onset gram-negative BSI from January 1, 2010 to December 31, 2012 at Palmetto Health Richland and Baptist Hospitals in Columbia, South Carolina, USA were identified. Multivariate linear regression was used to examine risk factors for prolonged duration of hospitalization among survivors. 


    Among 474 unique patients, 384 (81%) and 90 (19%) had BSI due to fluoroquinolone-susceptible (FQ-S) and FQ-R gram-negative bacilli, respectively. Overall, median age was 66 (interquartile range 52-79) years and 189 (40%) were men. Compared to patients with BSI due to FQ-S bloodstream isolates, those with FQ-R isolates were more likely to be men (53% vs. 37% P=0.004), have a Pitt bacteremia score ≥4 (31% vs. 21% P=0.03), and receive inappropriate empirical antimicrobial therapy (26% vs. 3% P<0.001). In univariate analysis, mean duration of hospitalization was longer in patients with FQ-R as compared to FQ-S isolates (11.6 vs. 9.3 days, parameter estimate 2.28, 95% confidence intervals [CI] 0.21, 4.35; P=0.03). However, after adjustments in multivariate model, FQ-R was not independently associated with prolonged hospital stay (Table).

    Risk factors for prolonged hospitalization in bloodstream infection


    Parameter estimate

    95% CI


    Male gender


    -1.13, 2.03


    Non-urinary source


    0.87, 3.98


    Pitt score (per point)


    1.11, 1.93




    -1.59, 2.60


    Inappropriate therapy


    0.40, 6.83



    FQ-R appears to be a marker for high acute severity of illness and inappropriate empirical antimicrobial therapy, both of which are associated with prolonged hospital stay following BSI. Rapid identification of FQ-R bloodstream isolates could improve empirical antimicrobial therapy and patient outcomes.

    Matthew Brigmon, MD1, Sarah Cain, BS2, P. Brandon Bookstaver, Pharm.D., BCPS, (AQ-ID), AAHIVE3, Joseph Kohn, Pharm.D., BCPS4, Helmut Albrecht, MD5 and Majdi Al-Hasan, MD5, (1)Medicine, Palmetto Health/Univ. of South Carolina Sch. of Med., Columbia, SC, (2)Univ. of South Carolina Sch. of Med., Columbia, SC, (3)Univ. of South Carolina Coll. of Pharmacy, Columbia, SC, (4)Palmetto Health Richland Hospital, Columbia, SC, (5)Internal Medicine, Univ. of South Carolina Sch. of Med., Columbia, SC


    M. Brigmon, None

    S. Cain, None

    P. B. Bookstaver, Durata Therapeutics: Scientific Advisor, Salary
    Cubist Pharmaceuticals: Grant Investigator, Research grant

    J. Kohn, None

    H. Albrecht, None

    M. Al-Hasan, None

    Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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