Risk factors and outcome of extended-spectrum beta-lactamase-producing Enterobacter cloacae bloodstream infections

Enterobacter cloacae is a major nosocomial pathogen that causes serious infections, including bloodstream infections (BSIs). The clinical significance of extended-spectrum beta-lactamase (ESBL) production in E. cloacae is not well established. A multicentre, retrospective, cohort study was conducted to identify clinical characteristics of patients with E. cloacae BSI. ESBL production was confirmed by genotypic methods. A total of 159 patients with E. cloacae BSI were identified at three medical centres in north-eastern USA. Amongst them, 16 patients (10.1%) harboured ESBL-producing E. cloacae. Independent risk factors for ESBL production included admission from a nursing home, the presence of a gastrostomy tube and history of transplant. For the outcome analysis, 15 consecutive patients who had ESBL-producing E. cloacae BSI prior to the study were included. Amongst the 31 patients with ESBL-producing E. cloacae, 8, 9, 4 and 2 patients received a carbapenem, cefepime, piperacillin/tazobactam and ciprofloxacin, respectively, as initial therapy. All patients who received a carbapenem (n = 8) were alive at 28 days, whereas 7 (38.9%) of 18 patients who received a non-carbapenem antibiotic did not survive (P = 0.06). Clinical failure at 96 h was observed in 2 (25.0%) of 8 patients who received a carbapenem and in 14 (77.8%) of 18 patients who received a non-carbapenem antibiotic (P = 0.03). Pulsed-field gel electrophoresis showed little clonality amongst the study isolates. The majority of isolates produced SHV-type ESBL, whereas two isolates produced CTX-M-type ESBL. Initial therapy with a carbapenem appears to be associated with improved clinical outcome in BSI due to ESBL-producing E. cloacae. (C) 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved

Clinical characteristics of bacteraemia caused by extended-spectrum β-lactamase-producing Enterobacteriaceae in the era of CTX-M-type and KPC-type β-lactamases

Clin Microbiol Infect 2012; 18: 887893 Abstract A multicentre, casecontrol study was conducted to assess risk factors and patient outcomes of bacteraemia caused by Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs) and Klebsiella pneumoniae carbapenemases (KPCs). One hundred and five and 20 patients with bacteraemia caused by ESBL-producing and KPC-producing organisms were matched to controls who had bacteraemia caused by non-ESBL/KPC-producing organisms, respectively. Independent risk factors for ESBL production included admission from a nursing home (OR 4.64; 95% CI 2.64-8.16), chronic renal failure (OR 2.09; 95% CI 1.11-3.92), the presence of a gastrostomy tube (OR 3.36; 95% CI 1.38-8.18), length of hospital stay before infection (OR 1.02; 95% CI 1.01-1.03), transplant receipt (OR 2.48; 95% CI 1.24-4.95), and receipt of antibiotics with Gram-negative activity in the preceding 30 days (OR 1.76; 95% CI 1.00-3.08). Twenty-eight-day crude mortality rates for patients infected with ESBL-producing or KPC-producing organisms and controls were 29.1% (34/117) and 19.5% (53/272), respectively (OR 1.70; 95% CI 1.04-2.80). On multivariate analysis, inadequate empirical therapy (OR 2.26; 95% CI 1.18-4.34), onset of bacteraemia while in the intensive-care unit (OR 2.74; 95% CI 1.47-5.11), Apache II score (OR 1.17; 95% CI 1.12-1.23) and malignancy (OR 2.66; 95% CI 1.31-5.41) were independent risk factors for mortality. CTX-M was the most common ESBL type in Escherichia coli, whereas SHV predominated in Klebsiella spp. and Enterobacter spp