Screening of c-di-GMP-Regulated Exopolysaccharides in Host Interacting Bacteria.

Bacterial exopolysaccharides (EPS) often confer a survival advantage by protecting the cell against abiotic and biotic stresses, including host defensive factors. They are also main components of the extracellular matrix involved in cell-cell recognition, surface adhesion and biofilm formation. Biosynthesis of a growing number of EPS has been reported to be regulated by the ubiquitous second messenger c-di-GMP, which promotes the transition to a biofilm mode of growth in an intimate association with the eukaryotic host. Here we describe a strategy based on the combination of an approach to artificially increase the intracellular level of c-di-GMP in virtually any gram-negative bacteria with a high throughput screening (HTS) for the identification of monosaccharide composition and carbohydrate fingerprinting of novel EPS, or modified variants, that can be involved in host-bacteria interactions.