Pseudomonas aeruginosa increases viscoelasticity and decreases transportability of artificial mucus.

Muco-obstructive lung diseases presenting with mucin hyperconcentration can have increased viscoelasticity that prevents the mucus in the airways from being easily transported and that is prone to infection from opportunistic pathogens including Pseudomonas aeruginosa (PA). The direct role that PA may have on decreasing mucus transportability has not yet been determined. In this study, PA was found to increase the viscosity and elasticity of artificial mucus replicating early and intermediate stages of muco-obstructive lung disease and reduce mucus transportability. Evaluation of how PA could be altering the mucus determined that PA degrades mucins with a metalloproteinase. Supernatant fractionation of PA determined that the potential mucinase was >100 kDa and therefore larger than previously identified PA metalloproteinases. Our study provides explanation as to why PA is detrimental to the progression of muco-obstructive lung disease by presenting its ability to actively impede mucus transport through mucin degradation and viscoelastic changes.