Intracellular glycosyl hydrolase PslG shapes bacterial cell fate, signaling, and the biofilm development of Pseudomonas aeruginosa

Abstract

Biofilm formation is one of most important causes leading to persistent infections. Exopolysaccharides are usually a main component of biofilm matrix. Genes encoding for glycosyl hydrolases are often found in gene clusters that are involved in the exopolysaccharide synthesis. It remains elusive about the functions of intracellular glycosyl hydrolase and why a polysaccharide synthesis gene cluster requires a glycosyl hydrolase. Here we systematically studied the role of intracellular PslG, a glycosyl hydrolase that is co-transcribed with 15 psl genes, which is responsible for the synthesis of exopolysaccharide Psl (ePsl), a key biofilm matrix polysaccharide in opportunistic pathogen Pseudomonas aeruginosa. We showed that lacking of PslG in this opportunistic pathogen alters the signaling function and structure of ePsl, changes the relative level of cyclic-di-GMP within daughter cells during cell division and shapes the localization of ePsl on bacterial periphery, thus results in long chains of bacterial cells, fast-forming and compact biofilm microcolonies. Our results revealed the important roles of intracellular PslG on cell fate and biofilm development.

Treating Bacterial Infections with Bacteriophage-Based Enzybiotics: In Vitro, In Vivo and Clinical Application

“…These include phage-derived enzymes: (1) peptidoglycan hydrolases (PGHs, which include endolysins and virion-associated peptidoglycan hydrolases) and (2) biofilm-disrupting enzymes (polysaccharide depolymerases, PSDs). In addition, among enzybiotics there are bacteria-derived enzymes: (3) biofilm-disrupting enzymes [ 19 , 20 ], (4) autolysins [ 21 , 22 , 23 , 24 ], which are bacterial enzymes that break down peptidoglycan to enable the separation of daughter cells following cell division, and (5) bacteriocins [ 24 , 25 , 26 , 27 , 28 ], which are bacteria-produced antibacterial proteins or peptides that inhibit the growth of closely related bacteria. Moreover, among enzybiotics are animal-derived enzymes including (6) the lysozymes found in natural body fluids, e.g., tears, saliva, milk, and mucous [ 24 , 27 , 29 ].…”