Ceftolozane-tazobactam for the treatment of ventilator-associated infections by colistin-resistant Pseudomonas aeruginosa.

The use of colistin for the treatment of multiresistant bacteria has led to the emergence of colistin-resistant strains of Gram-negative bacilli. Treatment of infections caused by these pan-drug-resistant bacteria is difficult owing to the paucity of effective antibiotics. We report two cases of ventilator-associated respiratory infection caused by pan-drug-resistant, colistin-resistant Pseudomonas aeruginosa that were successfully treated with ceftolozane-tazobactam.