Abstract: Methods for Cystic Fibrosis disease assessment in an individual comprise detecting the presence or absence of outer membrane protein in a sample from an individual or the methods comprise detecting the presence or absence of outer membrane protein antibodies in a sample from an individual. Methods for treating anaerobic Pseudomonas aeruginosa biofilms in Cystic Fibrosis disease comprise detecting the presence of outer membrane protein in a sample from an individual; and selecting a therapy regimen for the individual based on the presence of OprF, wherein the anaerobic Pseudomonas aeruginosa biofilms in Cystic Fibrosis disease are treated by the therapy regimen or the methods comprise detecting the presence of outer membrane protein antibodies in a sample from an individual; and selecting a therapy regimen for the individual based on the presence of OprF antibodies; wherein the anaerobic Pseudomonas aeruginosa biofilms in Cystic Fibrosis disease are treated by the therapy regimen.