Antimicrobial resistance is a major concern in hospitals throughout the world. Resistant pathogens that cause hospital-acquired infections have contributed to increased morbidity and mortality among hospitalised patients (1). Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia worldwide (2-4). The incidence of imipenem-resistant Pseudomonas aeruginosa (IRPA) is increasing. The National Nosocomial Infections Surveillance System reported a 15% increase in the isolation of IRPA among nosocomially-infected patients in 2003, in comparison to 1998 to 2002 (5). In addition, we have seen a high incidence of IRPA in hospitals in Brazil (6).