Neutrophils play an ongoing role in preventing bacterial pneumonia by blocking the dissemination of Staphylococcus aureus from the upper to the lower airways

Abstract

Staphylococcus aureus is found in the nasal cavity of up to 30% of the human population. Persistent nasal carriage of S. aureus is a risk factor for influenza virus-induced secondary bacterial pneumonia. There is limited understanding of the factors that cause S. aureus to shift from the upper to the lower respiratory tract and convert from a commensal organism to an invasive pathogen. Here we show that neutrophils actively prevent S. aureus dissemination. Establishment of a mouse model of localized S. aureus nasal carriage revealed variations in the longevity of persistence of S. aureus isolates. Improved persistence within this site was associated with reduced nasal inflammation, less neut..