title: Nosocomial outbreak of CTX-M-15-producing E. coli in Norway.
abstract: Seven E. coli isolates expressing resistance to 3rd generation cephalosporins were recovered from blood (n=2), kidney and lung tissue (n=1), and urinary tract (n=4) samples from seven patients hospitalised or recently discharged from the Divisions of Geriatrics and Pulmonary Medicine, Central Hospital of Rogaland, between July and September 2004. All isolates expressed a typical ESBL-cefotaximase profile (cefotaxime MIC>ceftazidime MIC) with clavulanic acid synergy. A bla(CTX-M-15) genotype was confirmed in six strains that were coresistant to gentamicin, nitrofurantoin, trimethoprim-sulfamethoxazole and ciprofloxacin. A bla(CTX-M-3) genotype was detected in the last strain. XbaI-PFGE patterns of the six bla(CTX-M-15) isolates revealed a clonal relationship. Bla(CTX-M-15) strains were also positive for the ISEcp1-like insertion sequences that have been shown to be involved in the mobilization of bla(CTX-M.) Further analyses revealed two bla(CTX-M-15)-positive E. coli urinary isolates clonally related to the outbreak strain from two different patients at the same divisions in January and February 2004. These patients were later re-hospitalised and one had E. coli with an ESBL-cefotaximase profile in sputum and nasopharyngeal specimen during the outbreak period. Clinical evaluation suggests that the CTX-M-producing E. coli strains contributed to death in three patients due to delayed efficient antimicrobial therapy. The outbreak emphasises the epidemic potential of multiple-antibiotic-resistant CTX-M-15-producing E. coli also in a country with low antibiotic usage and low prevalence of antimicrobial resistance.
authors.affiliation: Reference Centre for Detection of Antimicrobial Resistance (K-res), Department of Microbiology and Infection Control, University Hospital of Northern Norway, Norway. Umaer.Naseer@fagmed.uit.no
authors.forename: Umaer
authors.initials: U
authors.lastname: Naseer
authors.forename: Olav B
authors.initials: OB
authors.lastname: Natås
authors.forename: Bjørg C
authors.initials: BC
authors.lastname: Haldorsen
authors.forename: Berit
authors.initials: B
authors.lastname: Bue
authors.forename: Heidi
authors.initials: H
authors.lastname: Grundt
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Walsh
authors.forename: Arnfinn
authors.initials: A
authors.lastname: Sundsfjord
mesh_terms: D001483:Base Sequence; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D017931:DNA Primers / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000235:genetics / Q000302:isolation & purification; D018432:Drug Resistance, Multiple; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000453:epidemiology*; D006801:Humans; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D012329:RNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000302:isolation & purification; D014552:Urinary Tract Infections / Q000382:microbiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases