title: The molecular and clinical epidemiology of enterobacteriaceae-producing extended-spectrum beta-lactamase in a tertiary care hospital.
abstract: To describe the epidemiology of Enterobacteriaceae-producing extended-spectrum beta-lactamase (EP-ESBL) in a non-outbreak setting, and to define the risk factors associated with colonization, a 5-month surveillance study was initiated. Ten of 333 patients were colonized with EP-ESBL, as defined by isoelectric focusing. Klebsiella sp. and Escherichia coli were the species most commonly harbouring these plasmid-mediated enzymes. Of the 16 SHV-producing isolates, 10 were SHV-3-like (pI 7.0) and six were SHV-5-like (pI 8.2). All isolates were resistant to ceftriaxone. Ceftazidime resistance was detected in 50% and 100% of SHV-3-like and SHV-5-like producing isolates, respectively. One patient was colonized with four different SHV-5-like producing Enterobacteriaceae. These isolates carried plasmids that were indistinguishable by restriction endonuclease analysis, indicating broad plasmid transfer within the patient. By logistic regression, haemodialysis was a strong risk factor for colonization with EP-ESBL, suggesting that, in our hospital, horizontal transmission is an important mechanism of dissemination of these resistant pathogens.
authors.affiliation: The Division of Infectious Diseases, Beth Israel-Deaconess Medical Center, and Harvard Medical School, Boston, MA, USA.
authors.forename: E
authors.initials: E
authors.lastname: D'Agata
authors.forename: L
authors.initials: L
authors.lastname: Venkataraman
authors.forename: P
authors.initials: P
authors.lastname: DeGirolami
authors.forename: L
authors.initials: L
authors.lastname: Weigel
authors.forename: M
authors.initials: M
authors.lastname: Samore
authors.forename: F
authors.initials: F
authors.lastname: Tenover
mesh_terms: D000046:Academic Medical Centers; D003428:Cross Infection / Q000188:drug therapy* / Q000201:enzymology / Q000453:epidemiology / Q000209:etiology; D004756:Enterobacteriaceae Infections / Q000188:drug therapy* / Q000201:enzymology / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010957:Plasmids; D012307:Risk Factors; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: C062555:beta-lactamase SHV-3; C117193:beta-lactamase SHV-5; D001618:beta-Lactamases