Methicillin-Resistant S. aureus Ventilator-Associated Pneumonia: Strategies to Prevent and Treat

Abstract

Ventilator-associated pneumonias (VAPs) due to methicillin-resistant Staphylococcus aureus (MRSA) are rising in incidence and pose unique challenges in their prevention and treatment. Risk factors for the development of MRSA VAP include nasal carriage, prior antibiotic therapy, prolonged mechanical ventilation, poor infection control practices, head trauma/coma, and viral infection. Measures to prevent the development of MRSA VAP include general VAP prevention strategies and reduction of S. aureus nasal carriage. S. aureus possesses a variety of transferable genetic elements that encode proteins conferring resistance to several antibiotics, including beta-lactams and glycopeptides. Successful treatment of MRSA VAP with currently available antibiotics has been poor. Current management guidelines recommend glycopeptides as initial therapy for MRSA VAP. However vancomycin success rates are low, ranging from only 35 to 57%. This may be due to the poor penetration of vancomycin into the lung, and alternate dosing regimens to increase tissue levels need to be further studied. Treatment with linezolid, which penetrates well into the lung, is associated with higher cure and survival rates. Further data are needed to evaluate the efficacy of new antibiotics in MRSA VAP.