The Aspergillus fumigatus secretome alters the proteome of Pseudomonas aeruginosa to stimulate bacterial growth: implications for co-infection

Individuals with cystic fibrosis are susceptible to co-infection by Aspergillus fumigatus and Pseudomonas aeruginosa, however P. aeruginosa eventually predominates as the primary pathogen. Several factors are likely to facilitate P. aeruginosa colonization in the airways, including alterations to the microbial environment. In this study, significant growth proliferation was observed in P. aeruginosa when the bacteria were exposed to culture filtrates produced by A. fumigatus in a nitrate-rich, nutrient-poor liquid broth, Czapek-Dox. Proteomic analysis of the A. fumigatus culture filtrate identified a significant number of environment-altering proteases and peptidases, which may contribute to the growth promoting effect observed when P. aeruginosa is exposed to this culture filtrate. These findings offer insights into the determinants that contribute to P. aeruginosa proliferation in the presence of A. fumigatus.