1413. Resistant Gram-Negative Bacterial Bloodstream Infections in Pediatrics: Descriptive Epidemiology from a Large Tertiary Hospital
Session: Poster Abstract Session: Epidemiology of Multiple Drug-Resistant Gram Negative Rods
Saturday, October 20, 2012
Room: SDCC Poster Hall F-H
  • Tom Fox. IDSA 2012 Poster. Final.pdf (1.3 MB)
  • Background: The epidemiology of bloodstream infections caused by resistant Gram-negative bacteria in children has not been well defined.  Pathogens resistant to third generation cephalosporins are responsible for an increasing proportion of pediatric bloodstream infections.  Selection of active empiric antimicrobial agents is directly proportional to patient outcome, thus knowledge of resistance epidemiology is vital in choosing the optimal therapy for these infections.

    Methods: A retrospective chart review was performed at Children’s Medical Center Dallas using an electronic database to identify Enterobacteriaceae blood culture isolates over a 5-year period (2006-2011).  Each isolate was matched to an individual patient and the medical chart reviewed.  Resistant strains were defined as those determined to be “intermediate” or “resistant” to any third-generation cephalosporin based on Clinical and Laboratory Standards Institute interpretive criteria. The total infection events and number of unique bacterial isolates were determined for resistant and susceptible strains.  The prevalence of resistance was calculated for each bacterial species, and trends over time were analyzed.

    Results: Resistant Enterobacteriaceae strains caused 14.4% (131/907) of bloodstream infections during the study period, and 13.8% (111/803) of the unique bacterial isolates were resistant.  Enterobacter species represented the majority (52.8%) of infections caused by resistant bacteria, whereas E. coli caused most infections (51.1%) amongst susceptible strains.  Enterobacter and Citrobacter species were the most likely pathogens to be resistant (35.4%, 28%), whereas resistance in E. coli and Salmonella species was uncommon (4.4%, 2.6%).  For all species combined, no trends in resistance were identified.

    Conclusion: In the previous five years, resistant bacteria were responsible for a significant proportion of Gram-negative bloodstream infections in our patient population.  Third generation cephalosporins remain an appropriate choice in the empiric treatment of E. coli bacteremia, but alternatives for initial therapy of Enterobacter bloodstream infections should be considered.

    Thomas G. Fox, MD1, Sean Nguyen, PharmD2, Ashlesha Kaushik, MD1, Divya Rajan, MD3 and Christopher D. Doern, PhD4, (1)Pediatric Infectious Disease, University of Texas Southwestern, Dallas, TX, (2)Pharmacy, Children's Medical Center Dallas, Dallas, TX, (3)Pediatrics, Children's Medical Center Dallas, Dallas, TX, (4)Pathology, Children's Medical Center Dallas, Dallas, TX


    T. G. Fox, None

    S. Nguyen, None

    A. Kaushik, None

    D. Rajan, None

    C. D. Doern, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 17th with the exception of research findings presented at the IDWeek press conferences.