Clinical Studies
Risk factors for the acquisition of carbapenem-resistant Escherichia coli among hospitalized patients

https://doi.org/10.1016/j.diagmicrobio.2008.08.014Get rights and content

Abstract

Carbapenem resistance among Gram-negative bacilli has become an increasingly serious problem worldwide, and the emergence and spread of carbapenem-resistant Escherichia coli (CREC) is also becoming a serious problem. To date, however, risk factors for CREC acquisition have not been determined, so we decided to evaluate this in hospitalized patients through matched case-control study. Nosocomially acquired CREC was isolated from 46 patients between January 1997 and December 2007. For each patient, 3 matched-control subjects were selected. Previous use of carbapenem (adjusted odds ratio [AOR], 6.50) and metronidazole (AOR, 4.25), the presence of biliary drainage catheter (AOR, 4.59), and prior hospital stay (AOR 1.02) were found as independent risk factors for CREC. Our results suggest that the nosocomial acquisition of CREC may be favored by the selection pressure of carbapenems and metronidazole and also related to prior hospital stay and the presence of biliary drainage catheter.

Introduction

Carbapenems, a class of β-lactam antibiotics with a broad spectrum of antibacterial activity, have been one of the last remaining therapeutic choices for infections caused by cephalosporin-resistant microorganisms. However, their effectiveness is being challenged by the emergence and spread of carbapenem-resistant Gram-negative rods, such as Pseudomonas aeruginosa and Acinetobacter baumannii (CDC NNIS System, 2004, Gaynes and Culver, 1992, Lee et al., 2004). Recently, carbapenem resistance in Escherichia coli is also emerging worldwide (Gulmez et al., 2008, Hong et al., 2005, Miriagou et al., 2003, Moloughney et al., 2005, Poirel et al., 2004, Stapleton et al., 1999, Urban et al., 2008).

Mechanisms causing resistance to the carbapenems in E. coli have been suggested to include the presence of an AmpC β-lactamase in association with the loss of porin (Poirel et al., 2004, Stapleton et al., 1999), metallo-β-lactamases (Miriagou et al., 2003), and class A carbapenemases such as Klebsiella pneumoniae carbapenemase type 2 (KPC-2) (Navon-Venezia et al., 2006) and KPC-3 (Hong et al., 2005). Recently, OXA-48–like carbapenemases and outer membrane protein loss were also reported (Gulmez et al., 2008).

Carbapenem-resistant E. coli (CREC) strains were 1st isolated in our hospital in 1997, and since then, they are being recovered steadily. After our limited observation and clinical experience with CREC, which poses a potential threat to the hospital infection control, we assessed the risk factors for CREC acquisition in hospitalized patients.

Section snippets

Case definition, control definition, and study design

A case-control study was conducted at the Asan Medical Center in Seoul, Korea, a 2200-bed tertiary-care teaching hospital with 159 intensive care unit (ICU) beds and approximately 10 000 admissions per year. The use of imipenem or meropenem at this institution is not restricted to specific wards or to treatment of infections due to microorganisms resistant to other agents, but, in principle, it is monitored and supervised by infectious disease specialists. The microbiology laboratory database

Results

During the 11-year study period, CREC was isolated from 46 patients who met the criteria for nosocomial acquisition: 1 patient in 1998, 8 in 1999, 3 in 2000, 2 in 2001, 10 each in 2002 and 2003, 1 in 2004, 3 in 2005, 5 in 2006, and 3 in 2007. A total of 138 patients were included in the control group.

Carbapenem-resistant E. coli was most frequently recovered from surgical drainage specimens (28.3%), followed by bile (21.7%), blood (13.0%), respiratory secretions (10.9%), ascitic fluid (8.7%),

Discussion

To date, there have been a few descriptions of CREC strains, with most reports describing the mechanisms responsible for carbapenem resistance (Bratu et al., 2007, Gulmez et al., 2008, Hong et al., 2005, Moloughney et al., 2005, Navon-Venezia et al., 2006, Poirel et al., 2004, Stapleton et al., 1999). Moreover, to our knowledge, the potential risk factors for the acquisition of CREC have not been assessed, although risk factors for carbapenem resistance to P. aeruginosa, A. baumannii, and K.

Acknowledgments

The authors thank the Medical Information Team, Asan Medical Center, Seoul, Korea, for database maintenance and data extraction and Sung-Cheol Yun of Division of Biostatistics, Center for Medical Research and Information, University of Ulsan College of Medicine, Seoul, Korea, for assistance with statistical analyses. This study was supported by a grant (2002-131) from the Asan Institute of Life Science, Seoul, Korea.

References (27)

  • HarrisA.D. et al.

    Control-group selection importance in studies of antimicrobial resistance: examples applied to Pseudomonas aeruginosa, enterococci, and Escherichia coli

    Clin. Infect. Dis.

    (2002)
  • HarrisA.D. et al.

    Risk factors for imipenem-resistant Pseudomonas aeruginosa among hospitalized patients

    Clin. Infect. Dis.

    (2002)
  • HongT. et al.

    Escherichia coli: development of carbapenem resistance during therapy

    Clin. Infect. Dis.

    (2005)
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