JAC Advance Access originally published online on March 28, 2009
Journal of Antimicrobial Chemotherapy 2009 63(6):1205-1214; doi:10.1093/jac/dkp108
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Original research |
Nationwide survey of extended-spectrum β-lactamase-producing Enterobacteriaceae in the French community setting
1 CNRS UMR 5234, Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité (MCMP), Université Bordeaux 2, Bordeaux, France 2 Laboratoire d’Analyses Médicales, La Ferté Bernard, France 3 Université Paris XII, CHU Henri Mondor, Créteil, France 4 Faculté de Médecine Pierre et Marie Curie (UPMC Paris 6), Bactériologie-Hygiène, Paris, France
Received 15 January 2009; returned 29 January 2009; revised 27 February 2009; accepted 2 March 2009
* Corresponding author. Tel: +33-5-57-57-10-75; Fax: +33-5-57-57-95-14; E-mail: corinne.arpin{at}bacterio.u-bordeaux2.fr
Objectives: The aim of this study was to assess the prevalence of the extended-spectrum β-lactamase (ESBL)-producing enterobacteria (ESBLE) in the French community, during a 2006 survey.
Methods: All enterobacteria isolated from urine samples of patients, exhibiting a decreased susceptibility to broad-spectrum cephalosporins, were analysed for their β-lactamase content (synergy test, isoelectrofocusing, conjugation transfer, PCR amplification and/or cloning experiments and sequencing). Additional co-resistances were investigated by PCR, sequencing and/or cloning. Epidemiological relationship was studied by PFGE for all species and, in addition, for Escherichia coli by the determination of the phylogenetic group, multilocus sequence type (ST) and O25b antigen. Characteristics of CTX-M-producing E. coli carriers were compared with other ESBLE carriers.
Results: Seventy-two ESBLE were collected from 71 patients. Most of them expressed a CTX-M enzyme (n = 42, comprising 40 E. coli), with a predominance of CTX-M-15 (n = 24); 10 CTX-M-15-producing E. coli belonged to the same clone (phylogroup B2, ST131, serotype O25b). The 30 remaining strains possessed a TEM- or SHV-type ESBL. In addition, three strains presented unusual co-resistances such as DHA-1 (n = 2), QnrB4 and ArmA. Risk factors for ESBLE acquisition were substantially less frequent when the ESBL was of the CTX-M type, except for prior antimicrobial therapy. Eighteen percent of the patients were considered to have true community-acquired ESBLE; most of them harboured a CTX-M-producing E. coli.
Conclusions: This first nationwide study reports an ESBLE prevalence of 1.1% in the French community setting in 2006, mainly related to the presence of CTX-M-producing E. coli strains; furthermore, unusual co-resistances rarely found in the community setting were occasionally observed, which may threaten future emergence.
Keywords: ESBLs , enterobacteria , CTX-M , community setting , risk factors