Method enriches bacteria found in people who have cystic fibrosis

Abstract

Pseudomonas aeruginosa is a common cause of chronic infections in people with cystic fibrosis. Detecting bacterial proteins in sputum—the best source of bacteria from patient airways—is difficult. Thus researchers don’t know whether P. aeruginosa produces different proteins in patient airways versus in a lab dish. By using two stages of centrifugation at different spin speeds, Xia Wu and coworkers at the University of Washington enriched bacteria from sputum to allow analysis of their proteins with liquid chromatography/tandem mass spectrometry (J. Proteome Res. 2019, DOI: 10.1021/acs.jproteome.9b00122). The researchers detected 1,304 P. aeruginosa proteins directly from sputum. Compared with the cultured bacteria, airway bacteria produced more of 67 proteins. Airway bacteria produced higher levels of proteins involved in iron and phosphate uptake and in the production and transport of alginate, a polysaccharide involved in the formation of bacterial biofilms. They produced less of 117 proteins, including many that are involved with carbon