CFTR and coinfection: In an effort to define the role of S. parasanguinis on airway infection with P. aeruginosa, the goals of this study were to (i) determine if S. parasanguinis-generated RNI can inhibit P. aeruginosa in the mammalian lung, (ii) determine the impact of S. parasanguinis, nitrite, and co-infection on the host immune response to P. aeruginosa, and (iii) determine the impact on CFTR on RNI-dependent antagonism of P. aeruginosa.