Current review of antimicrobial treatment of nosocomial pneumonia caused by multidrug-resistant pathogens

Nosocomial pneumonia (including ventilator-associated pneumonia; VAP), a consistently difficult-to-treat entity, is frequently caused by multidrug-resistant (MDR) or pandrug-resistant (PDR) bacteria. Given the high mortality rates caused by drug-resistant bacteria and the difficulty of developing new potent antibiotics to target the problematic pathogens, combination regimens are under ardent evaluation as new strategies to overcome increasing drug resistance. Adjustment of the administration method of certain β-lactams (meropenem, or imipenem/cilastatin), or combination of tigecycline with some agents, may show promise with regard to successful management of MDR or PDR Acinetobacter baumannii pneumonia. Additionally, vancomycin plus rifampicin is an effective regimen against nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA) responding poorly to vancomycin monotherapy. The clinical appropriateness of parenteral colistin against pneumonia caused by MDR A. baumannii has been established in a clinical trial. Facing the decline of clinical vancomycin efficacy after initial use, linezolid might be the drug of choice with regard to the treatment of MRSA-VAP. The role of tigecycline monotherapy for the management of nosocomial pneumonia caused by MRSA and extended-spectrum β-lactamase-producing Enterobacteriaceae needs to be cautiously evaluated.