1579. Risk factors for ambulatory urinary tract infections caused by high MIC-fluoroquinolone susceptible E. coli in women
Session: Poster Abstract Session: Multidrug-Resistant Gram Negative Rods
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • final poster highmic.pdf (133.4 kB)
  • Background:   Several studies have reported an increasing prevalence of high MIC fluoroquinolone susceptible E. coli (high MIC-FQSEC) which are the E. coli isolates with reduced susceptibility to FQs. High MIC-FQSEC potentially results in development of fully FQ-resistance and delayed response to FQ therapy. To date, risk factors for infection caused by high MIC-FQSEC have never been successfully identified. Our study aimed to identify risk factors for ambulatory urinary tract infections (UTIs) caused by high MIC-FQSEC in women.

    Methods: We conducted a case-control study of female subjects with UTIs caused by FQSEC at outpatient services within University of Pennsylvania Health System, Philadelphia. Of subjects in whom FQSEC (a levofloxacin-MIC < 4 mcg/mL) were isolated on urine culture, we included only those who met our study criteria of UTIs. Cases were subjects with UTIs caused by high MIC-FQSEC (a levofloxacin-MIC ≤ 0.12 mcg/mL) and controls were subjects with UTIs caused by low MIC-FQSEC, (a levofloxacin-MIC > 0.12 but < 4 mcg/mL). Cases and controls were compared with regard to demographics, comorbid conditions, and recent use of medications (particularly antibiotics) within the 90 days prior to the UTI onset. We obtained all necessary data from HUP clinical microbiology laboratory database and Penn data store.

    Results: Two thousand female subjects with FQSEC-UTIs were included during May 1, 2008 to April 30, 2011. A total of 91.8% (1,836/2,000) had low MIC-FQSEC UTI while 8.2% (164/2000) had high MIC-FQSEC UTI. Mean age was 56.9+/-22.6 years among cases and 57.3+/-22.0 years among controls. Approximately one-fourth of subjects in both groups had at least one underlying diseases. Independent risk factors for high MIC-FQ susceptibility identified by multiple logistic regression analysis are shown in the table.

    Conclusion: In addition to Asian race and having chronic renal diseases, recent use of nitrofurantoin was identified as a risk factor. Since this study was conducted among a relatively healthy population with a low prevalence of recent antibiotic use, we did not have enough power to identify any associations between high MIC-FQSEC and other uncommonly used antibiotics.

    Description: C:\Users\Admin\Desktop\highmic.jpg

    Pinyo Rattanaumpawan, MD, MSCE1, Irving Nachamkin, DrPH, MPH2, Joshua Metlay, MD, PhD1, Theoklis Zaoutis, MD, MSCE1, Warren Bilker, PhD1, Jason Roy, PhD1, Ebbing Lautenbach, MD, MPH, MSCE1 and for the CDC Prevention Epicenter Program, (1)Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, (2)Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA


    P. Rattanaumpawan, None

    I. Nachamkin, None

    J. Metlay, None

    T. Zaoutis, None

    W. Bilker, None

    J. Roy, None

    E. Lautenbach, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.