1753. The Molecular Epidemiology of Extended-Spectrum β-Lactamase (ESBL) and Klebsiella pneumoniae Carbapenemase (KPC) producing Enterobacteriaceae (CRE) in Chicago Children: A Multi-Center Study
Session: Poster Abstract Session: Pediatric Bacterial Infections
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • Logan_IDweek2015_Poster_Final.pdf (961.0 kB)
  • Background: Multi-Drug resistant (MDR) Gram-negative bacilli (GNB) are a growing cause of infections in children. Our long term goals are to describe the impact and define the clinical and molecular epidemiology of this emerging pediatric health threat. Here, we report our molecular findings of ESBL and CRE genotypes and phenotypes in Enterobacteriaceae from children in Chicago.

    Methods: We conducted a retrospective cohort study of GNB isolates recovered from children ages 0-18 years hospitalized between 2011 - 2014 at three Chicago hospitals. We used DNA microarray (Check-Points™) to detect ESBL, plasmid-mediated AmpC (pAmpC) and CRE beta-lactamase (bla) genes.  PCR was performed to assess for plasmid-mediated fluoroquinolone resistance (PMFQR). Repetitive-sequence-based PCR (rep-PCR) and multilocus sequence typing (MLST) were performed to assess isolate similarity. Plasmid replicon typing was conducted to classify plasmids.

    Results: The median age of the study population was 4.3 years, 55% were female, and 44% were outpatients. Most isolates (68%) were from urine. One hundred ninety-seven isolates exhibiting ESBL or CRE phenotypes were analyzed; 214 bla genes were detected. The most common species was E. coli (61%), and the most frequent genotype was blaCTX-M (46%); 1% (2/197) carried blaKPC and PMFQR was found in 52/84 (62%) isolates. Overall, pAmpC (blaACT/MIR and blaCMY) were found in 13% (26/197) of isolates and in 71% (17/24) of Enterobacter spp.  The predominant E. coli phylogroup was B2 (66%) associated with ST43 (ST131) containing blaCTX-M-1 group (67%), and replicon types F1A, F11, F1B. The blaKPC harboring K. pneumoniae were non ST258 containing replicon I1, A/C. Enterobacter harboring blaSHV/ACT-MIR contained replicon F11A.

    Conclusion: ESBL producing Enterobacteriaceae and CRE in children are diverse in origin. Like in adults, the predominant strains responsible for ESBL phenotypes are B2-ST43 clonal groups in E. coli containing blaCTX-M-1 group (containing blaCTX-M-15).  In contrast, CRE were rare, and blaKPC bearing K. pneumoniae isolates were non ST258, the predominant strain identified in adults. Plasmid-mediated AmpC may account for a larger percentage of transferable resistance than previously recognized.

    Latania K. Logan, MD1,2,3, Andrea M. Hujer, BS2,4, Steve H. Marshall, MS5, T. Nicholas Domitrovic, BA2, Susan D. Rudin, BS2,4, Anand Karadkhele, MD, MPH6, Felicia a. Scaggs, MD6, Xiaotian Zheng, MD PhD7,8, Nadia K. Qureshi, MD9, Mary K. Hayden, MD, FIDSA, FSHEA3,10,11 and Robert Bonomo, MD2,12, (1)Pediatrics, Section of Infectious Diseases, Rush University Medical Center, Chicago, IL, (2)Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, (3)Rush Medical College, Chicago, IL, (4)Case Western Reserve University, Cleveland, OH, (5)Louis Stokes Cleveland VA Medical Center, Cleveland, OH, (6)Rush University Medical Center, Chicago, IL, (7)Microbiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, (8)Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, (9)Loyola University Medical Center, Maywood, IL, (10)Department of Internal Medicine, Section of Infectious Diseases, Rush University Medical Center, Chicago, IL, (11)Department of Pathology, Rush University Medical Center, Chicago, IL, (12)Pharmacology, Molecular Biology, and Microbiology, Case Western Reserve University, Cleveland, OH

    Disclosures:

    L. K. Logan, None

    A. M. Hujer, None

    S. H. Marshall, None

    T. N. Domitrovic, None

    S. D. Rudin, None

    A. Karadkhele, None

    F. A. Scaggs, None

    X. Zheng, None

    N. K. Qureshi, None

    M. K. Hayden, None

    R. Bonomo, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.