Association between chronic hemodialysis and bloodstream infections caused by chromosomally mediated AmpC-producing Enterobacteriaceae

Abstract

Background: The combination of inherent antimicrobial resistance and high mortality after bloodstream infections (BSIs) caused by chromosomally mediated AmpC-producing Enterobacteriaceae (CAE) emphasizes the importance of identifying patients at risk of BSI because of these bacteria. This retrospective case-control study examines chronic hemodialysis among other risk factors for BSI caused by CAE.

Methods: Hospitalized adults with Enterobacteriaceae BSI from January 1, 2010-June 30, 2014, at 2 large community hospitals in the Southeastern United States were identified. Multivariate logistic regression was used to examine risk factors for CAE BSI.

Results: Among 831 Enterobacteriaceae bloodstream isolates, 106 (13%) met the phenotypic definition of CAE. Enterobacter spp accounted for 47% (50/106) of CAE BSIs. Chronic hemodialysis was an independent risk factor for CAE BSI (adjusted odds ratio [aOR], 2.34; 95% confidence interval [CI], 1.21-4.44). Other predictors of CAE BSI included nosocomial acquisition (aOR, 1.72; 95% CI, 1.02-2.87) and exposure to β-lactam antibiotics within the last 30 days (aOR, 2.39; 95% CI, 1.37-4.14).

Conclusions: To our knowledge, this is the first study to demonstrate an increased risk of CAE BSI in patients with end-stage renal disease undergoing chronic hemodialysis. This highlights the importance of effective infection prevention and antimicrobial stewardship interventions in hemodialysis clinics. Further studies to examine the impact of antibiotics on intestinal microbiota and rates of CAE colonization in this patient population are warranted.

Keywords: Bacteremia; Enterobacter cloacae; Serratia marcescens; antimicrobial agents; end-stage renal disease; sepsis; β-lactamases.