366. Sites of Colonization in Hospitalized Patients with Infections Caused by Extended-Spectrum Beta-Lactamase Producing Escherichia coli and Klebsiella pneumoniae
Session: Poster Abstract Session: HAI: Multi Drug Resistant Gram Negatives
Thursday, October 27, 2016
Room: Poster Hall
  • Poster.pdf (849.6 kB)
  • Background: Extended-spectrum beta-lactamase (ESBL)-producing organisms have evolved to become a phenomenon of paramount medical importance. Few reports exist of ESBL-producing organisms that have been isolated from rectal, axillary, and respiratory samples during investigations of outbreaks, raising concern for colonization at sites other than the primary site. The objective of this study was to determine whether patients infected with ESBL-producing organisms are colonized at multiple body sites.

    Methods: Adult patients hospitalized between 2011 and 2014 at a tertiary hospital in Lebanon, and who were diagnosed with an infection due to ESBL-producing E. coli (ESBL-EC) or Klebsiella pneumoniae ESBL-KP) were prospectively enrolled. Screening cultures for potential sites of colonization were performed on each patient upon enrollment in the study. Culture specimens were obtained from the skin (axillary, umbilical, and inguinal areas), nasopharynx, urine, rectum, and wounds, if applicable. Polymerase chain reaction (PCR) for resistance genes was performed on DNA extracted from bacterial isolates. Pulsed-field gel electrophoresis (PFGE) was carried on isolates to determine their genomic relatedness.

    Results: One hundred patients were included. Only 22 patients had positive cultures from sites other than the primary site of infection, i.e. were colonized with ESBL-producing organisms. The most common ESBL gene was CTX-M-15 (80% of isolates) followed by TEM-1 (39% of isolates). In 11 of 22 patients, isolates collected from the same patient were 100% genomically related, while in the remaining patients genomic relatedness ranged from 42.9% to 97.1%. There were no significant correlations between any of the patient factors and the results of molecular analysis.

    Conclusion: We found that a minority of patients with ESBL-EC and ESBL-KP infections are colonized at body sites other than the primary site of infection. CTX-M-15 is the predominant ESBL gene harbored by these strains, and multiple bacterial clones are circulating at our institution. There is no evidence to justify routine active surveillance in our patient population. While standard precautions are probably sufficient, other infection control measures such as antibiotic stewardship should be implemented to curb the spread of ESBL-producing organisms.

    Zeina Kanafani, MD1, Sukayna Fadlallah, MS2, Sarah Assaf, MD2, Khalil Anouti, MD3, Kohar Annie Kissoyan, MS2, Jad Sfeir, MD1, Tamara Nawar, MD2, Mohamad Yasmin, MD2 and Ghassan Matar, PhD4, (1)Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon, (2)American University of Beirut Medical Center, Beirut, Lebanon, (3)american University of Beirut Medical Center, Beirut, Lebanon, (4)American University of Beirut, Beirut, Lebanon


    Z. Kanafani, None

    S. Fadlallah, None

    S. Assaf, None

    K. Anouti, None

    K. A. Kissoyan, None

    J. Sfeir, None

    T. Nawar, None

    M. Yasmin, None

    G. Matar, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.