Acquisition of carbapenem-resistant Gram-negative bacilli in intensive care unit: Predictors and molecular epidemiology

{Objectives. - We had for aim to determine the risk factors for acquiring carbapenem-intermediate or -resistant Gram-negative bacilli (CR-GNB) in an intensive care unit (ICU) and to identify the resistance mechanisms involved. Patients and methods. - We conducted an observational prospective cohort study during 6 months in medical and surgical ICUs of the Besancon Teaching Hospital. Patients with acquired CR-GNB were patients whose cultures (screening or diagnosis) became positive more than 48 h after admission to the ICU. The risk factors for ICU-acquired CR-GNB were determined by multivariate logistic regression. CR-GNB isolates were typed by pulsed-field gel electrophoresis (PFGE) and screened for resistance mechanisms with phenotypic and genotypic tests. Results. - Twenty-three of the 347 included patients had acquired a CR-GNB. The multivariate analysis revealed significant associations between this acquisition and the duration of previous treatments with piperacillin-tazobactam (adjusted odds ratio [aOR], 1.13