BACKGROUND: Ertapenem has proven to be effective for extended-spectrum beta-lactamases-producing Enterobacteriaceae but lacks activity against non-fermenters; de-escalation to this antibiotic may reduce the selection of resistance to Pseudomonas aeruginosa and improve clinical outcomes. AIM: To evaluate the clinical impact of de-escalation from broad-spectrum anti-pseudomonal agents to ertapenem, a non-pseudomonal antibiotics for Enterobacteriaceae infections in critically-ill patients