The ClpXP Protease Contributes to Staphylococcus aureus Pneumonia.

Staphylococcus aureus is a leading cause of pneumonia. We show here that the ClpXP protease involved in protein turnover is important for pathogenesis in a murine model of acute pneumonia. Staphylococcus aureus lacking this protease is attenuated in vivo, being rapidly cleared from the airway and leading to decreased immune cell influx and inflammation. Characterization of defined mutations in vitro identified defects in intracellular survival and protection against neutrophil killing. Our results further expand on what is known about ClpXP in the pathogenesis of S. aureus to include the respiratory tract.