Applying a polysaccharide lyase from <i>Stenotrophomonas maltophilia</i> to disrupt alginate exopolysaccharide produced by <i>Pseudomonas aeruginosa</i> clinical isolates

<i>Pseudomonas aeruginosa</i> is a major opportunistic human pathogen in part due to its ability to synthesize biofilms that confer antibiotic resistance. Biofilm is a mixture of polysaccharides, DNA, and proteins that encapsulate cells, protecting them from antibiotics, disinfectants, and other cleaning agents. Due to its ability to increase antibiotic and immune resistance, the exopolysaccharide alginate plays a large role in airway inflammation and chronic <i>P. aeruginosa</i> infection. As a result, colonization with <i>P. aeruginosa</i> is the leading cause of morbidity and mortality in CF patients. Thus, it is an obvious target to improve the treatment regimen for <i>P. aeruginosa</i> infection. In this study, we demonstrate that polysaccharide lyase, Smlt1473, inhibits alginate secretion and degrades established alginate from a variety of mucoid <i>P. aeruginosa</i> clinical isolates. Additionally, Smlt1473 differs from other alginate lyases in that it is active against acetylated alginate, which is secreted during chronic lung infection. These results suggest that Smlt1473 may be useful in treating infections associated with alginate-producing <i>P. aeruginosa</i>, as well as have the potential to reduce <i>P. aeruginosa</i> EPS in non-clinical settings.