392. Epidemiology of Carbapenemase-Producing Enterobacteriaceae (CPE) in a Tertiary Care Hospital. 
Session: Poster Abstract Session: Gram Negative Infection - Epidemiology and Prevention
Friday, October 21, 2011
Room: Poster Hall B1
  • 10-10-11-CRE.pdf (457.6 kB)
  • Background: 

    Since 2009, the incidence of carbapenemase-producing Enterobacteriaceae (CPE) significantly increased at our institution.  We aimed to study the molecular epidemiology of these emerging isolates.


    We performed a retrospective review of all adult patients with clinical cultures confirmed as CPE by positive modified Hodge test from 5/2009- 5/2010 at University of Michigan Health System (UMHS).  Clinical information was obtained from electronic medical records.  Available CPE isolates were analyzed by PCR and sequencing of 16S rRNA encoding gene and blaKPC locus.  Multilocus sequence typing (MLST) was used to characterize Klebsiella pneumoniae isolates.


    25 adult patients (mean age 61.8 years) were found to have 26 CPE isolates, identified as  K. pneumoniae (72%), Klebsiella oxytoca (8%), Citrobacter freundii (8%), Enterobacter cloacae (8%), Enterobacter aerogenes (4%), and Escherichia coli  (4%). The sources of isolates were urine 13, lungs 7, blood 4, and wound in 3 patients. 24% of patients had malignancy and 28% had transplant.  Acquisition was attributable to UMHS in 60% and other health care facilities in 32% cases respectively. Within 90 days prior to culture, 64% patients had ICU stay and mechanical ventilation, 80% had central lines and 92% had urinary catheters.  All patients had antibiotic exposure including piperacillin/tazobactam (64%), cephalosporins (60%), quinolones (32%) and carbapenems (28%).  Mean length of stay from admission to positive culture was 21.6 days (median 6, range 0-127).  Mortality at discharge was 12%.  PCR and sequence analysis of the blaKPC locus of 20 patient isolates showed that 75% carried the KPC-3 allele and 25% the KPC-2 allele.  Nearly all (94%) K. pneumoniae isolates carried the KPC-3 allele. MLST of 10 representative KPC-3 positive K. pneumoniae isolates revealed that all belonged to a single clonal lineage ST-258.


    Molecular epidemiology of CPE suggests that KPC-3 producing K. pneumoniae isolates of a common lineage, sequence type (ST-258), are emerging in our hospital.  While this is a dominant sequence type throughout the United States, this study is the first to report its presence in Michigan. 

    Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

    Ruchika Jain, MD1, Walk Seth, PhD1, David Aronoff, MD1, Vincent B Young, MD/PhD1, Duane Newton, PhD2, Carol Chenoweth, MD1 and Laraine Washer, MD1, (1)Internal Medicine-Infectious Diseases, University of Michigan Health System, Ann Arbor, MI, (2)Department Of Pathology, University of Michigan Health System, Ann Arbor, MI


    R. Jain, None

    W. Seth, None

    D. Aronoff, None

    V. B. Young, None

    D. Newton, None

    C. Chenoweth, None

    L. Washer, 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.