Epidemiology and risk factors for isolation of Escherichia coli producing CTX-M-type extended-spectrum β-lactamase in a large U.S. Medical Center - Abstract

A case-case-control study was conducted to identify independent risk factors for recovery of Escherichia coli strains producing CTX-M-type extended-spectrum β-lactamases (CTX-M E. coli) within a large Southeastern Michigan medical center.

Unique cases with isolation of ESBL-producing E. coli from February 2010 through July 2011 were analyzed by PCR for blaCTX-M, blaTEM, and blaSHV genes. Patients with CTX-M E. coli were compared to patients with E. coli strains not producing CTX-M-type ESBLs (non-CTX-M E. coli) and uninfected controls. Of 575 patients with ESBL-producing E. coli, 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-M E. coli (282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-M E. coli patients and to uninfected controls. Independent risk factors for CTX-M E. coli isolation compared to non-CTX-M E. coli included male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillins and/or trimethoprim-sulfamethoxazole. Compared to uninfected controls, independent risk factors for isolation of CTX-M E. coli included presence of a urinary catheter, previous urinary tract infection, exposure to oxyimino-cephalosporins, dependent functional status, non-home residence, and multiple comorbid conditions. Within 48 h of admission, community-acquired CTX-M E. coli (n = 51 [16%]) and non-CTX-M E coli (n = 11 [19%]) strains were isolated from patients with no recent health care contacts. CTX-M E. coli strains were more resistant to multiple antibiotics than non-CTX-M E. coli strains. CTX-M-encoding genes, especially blaCTX-M-15 type, represented the most common ESBL determinants from ESBL-producing E. coli, the majority of which were present upon admission. Septic patients with risk factors for isolation of CTX-M E. coli should be empirically treated with appropriate agents. Regional infection control efforts and judicious antibiotic use are needed to control the spread of these organisms.

Written by:
Hayakawa K, Gattu S, Marchaim D, Bhargava A, Palla M, Alshabani K, Gudur UM, Pulluru H, Bathina P, Sundaragiri PR, Sarkar M, Kakarlapudi H, Ramasamy B, Nanjireddy P, Mohin S, Dasagi M, Datla S, Kuchipudi V, Reddy S, Shahani S, Upputuri V, Marrey S, Gannamani V, Madhanagopal N, Annangi S, Sudha B, Muppavarapu KS, Moshos JA, Lephart PR, Pogue JM, Bush K, Kaye KS.   Are you the author?
Division of Infectious Diseases, Wayne State University, Detroit Medical Center, Detroit, Michigan, USA.

Reference: Antimicrob Agents Chemother. 2013 Aug;57(8):4010-8.
doi: 10.1128/AAC.02516-12


PubMed Abstract
PMID: 23752516

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