1613. Multidrug-Resistant Enterobacteriaceae: Prevalence of Gastrointestinal Colonization and Short-Term Secondary Transmission in a Tertiary-Care Hospital
Session: Poster Abstract Session: Multidrug-Resistant Gram Negative Rods
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • PosterIDWEEK2013_BGNMR.pdf (1.1 MB)
  • Background: The steadily increasing occurrence of multidrug-resistant Enterobacteriaceae (MDRE) is concerning, especially in hospitalized patients. This study aims to determine the prevalence of gastrointestinal colonization of MDRE with plasmid-mediated β-lactamases in our hospital and to evaluate their short-term transmission.

    Methods: From December 10th to 13th 2012, all patients admitted to our hospital were screened by rectal swabbing. ChromID ESBL and ChromID CARBA agar (bioMérieux, Marcy-L’Étoile, France) were used to identify multidrug-resistant isolates. Further identification and susceptibility testing were performed by Vitek 2 (bioMérieux). Confirmation of resistance mechanisms by polymerase chain reaction (PCR) was performed by the Quebec Laboratory of Public Health. No supplementary infection control precautions were initiated for patients having a positive MDRE screening. Also, patients in the same room as carriers were identified and screened at discharge from hospital or up to a month after initial screening. Clinical and demographic data were collected through chart reviewing.

    Results: Of 449 patients screened, 7.6% (n = 34) were colonized with a MDRE. Resistance mechanisms confirmed by PCR were as follows: 64.7% (n=22) had an extended spectrum β-lactamase (ESBL), 20.6% (n=7) a plasmid-mediated AmpC cephalosporinase (AmpC), 5.9% (n=2) an oxacillinase (OXA-1) and 8.8% (n=3) a combination of resistance mechanisms (ESBL with AmpC or ESBL with OXA-1). The most frequent genes were the CTX-M for the ESBL group and CIT for the plasmid-mediated AmpC group. No carbapenemase-producing bacteria were found in our cohort. A total of 39 contact patients were identified and of these, 24 were screened. No transmission from colonized patients to room contacts was documented, but four contacts nosocomially acquired a MDRE strain within less than a month of hospitalization. 

    Conclusion: Nearly one out of ten patients was colonized with MDRE in our center. Nevertheless, no short-term transmission by room contact with MDRE gastrointestinal carriers was observed in our study. This supports the hypothesis that the screening and isolation of carriers are not required routinely.

    Philippe Morency-Potvin, MD1,2, Valery Lavergne, MD, MSc, FRCPC1,2, Chantal Cloutier3, Brigitte Lefebvre, PhD4, Gilbert Pichette, MD, FRCPC1,2 and Catherine Tsimiklis, MD1,2, (1)Medical Microbiology, Hôpital Du Sacré-Coeur De Montréal, Montréal, QC, Canada, (2)Microbiology and Immunology, Université De Montréal, Montréal, QC, Canada, (3)Infection Control and Prevention, Hôpital Du Sacré-Coeur De Montréal, Montréal, QC, Canada, (4)Laboratoire De Sante Publique Du Quebec, Ste-Anne-de-Bellevue, QC, Canada


    P. Morency-Potvin, None

    V. Lavergne, None

    C. Cloutier, None

    B. Lefebvre, None

    G. Pichette, None

    C. Tsimiklis, bioMérieux: Investigator, Research grant

    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.