[Outbreak of multidrug-resistant CTX-M-9-producing Enterobacter cloacae complex in an intensive care unit]

Clinical and epidemiological description of an outbreak in an intensive care unit (ICU) caused by a strain of multidrug-resistant Enterobacter cloacae complex carrying a CTX-M-9-type extended-spectrum β-lactamase (ESBL).

A retrospective study of the clinical and epidemiological features of the outbreak caused by E.cloacae complex was performed. Identifying and studying the sensitivity of the strains were performed using the semi-automated system BD Phoenix™, and the characterisation of ESBL using PCR and sequencing. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE).

During February 2014, 6 patients (50% women; mean age: 61.5 years; age range: 44-76 years) admitted to the ICU of the Hospital of Pontevedra (CHOP) presented resistant E.cloacae complex isolates to extended-spectrum cephalosporins. Three patients developed infection; one had primary bacteraemia and septic shock, and 2 with ventilator-associated pneumonia. In the remaining three cases E.cloacae complex isolates were considered as colonisation. Phenotypic and genotypic analysis revealed that all isolates had the same PFGE profile and carried the same CTX-M-9 ESBL. The outbreak was controlled by improving universal precautions and contact isolation of patients infected and/or colonized.

The clinical and epidemiological features of an outbreak in an ICU caused by E.cloacae complex carrying CTX-M-9 are described.