Biofilm exopolysaccharides alter sensory-neuron-mediated sickness during lung infection.

Infections of the lung cause observable sickness thought to be secondary to inflammation. Signs of sickness are crucial to alert others via behavioral-immune responses to limit contact with contagious individuals. Gram-negative bacteria produce exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on sickness remains uncertain.

Sensory Perception in Bacterial Cyclic Diguanylate Signal Transduction.

Cyclic diguanylate (c-di-GMP) signal transduction systems provide bacteria with the ability to sense changing cell status or environmental conditions and then execute suitable physiological and social behaviors in response. In this review, we provide a comprehensive census of the stimuli and receptors that are linked to the modulation of intracellular c-di-GMP. Emerging evidence indicates that c-di-GMP networks sense light, surfaces, energy, redox potential, respiratory electron acceptors, temperature, and structurally diverse biotic and abiotic chemicals.

Bacterial cyclic diguanylate signaling networks sense temperature.

Many bacteria use the second messenger cyclic diguanylate (c-di-GMP) to control motility, biofilm production and virulence. Here, we identify a thermosensory diguanylate cyclase (TdcA) that modulates temperature-dependent motility, biofilm development and virulence in the opportunistic pathogen Pseudomonas aeruginosa. TdcA synthesizes c-di-GMP with catalytic rates that increase more than a hundred-fold over a ten-degree Celsius change.

PelX is a UDP--acetylglucosamine C4-epimerase involved in Pel polysaccharide-dependent biofilm formation.

Pel is a GalNAc-rich bacterial polysaccharide that contributes to the structure and function of biofilms. The operon is highly conserved among diverse bacterial species, and Pel may therefore be a widespread biofilm determinant. Previous annotation of gene clusters has helped us identify an additional gene, , that is present adjacent to in >100 different bacterial species.

Elevated exopolysaccharide levels in Pseudomonas aeruginosa flagellar mutants have implications for biofilm growth and chronic infections.

Pseudomonas aeruginosa colonizes the airways of cystic fibrosis (CF) patients, causing infections that can last for decades. During the course of these infections, P. aeruginosa undergoes a number of genetic adaptations.

Measuring Cyclic Diguanylate (c-di-GMP)-Specific Phosphodiesterase Activity Using the MANT-c-di-GMP Assay.

The second messenger, cyclic diguanylate (c-di-GMP), regulates a variety of bacterial cellular and social behaviors. A key determinant of c-di-GMP levels in cells is its degradation by c-di-GMP-specific phosphodiesterases (PDEs). Here, we describe an assay to determine c-di-GMP degradation rates in vitro using 2'-O-(N'-methylanthraniloyl)-cyclic diguanylate (MANT-c-di-GMP).

Precision-engineering the Pseudomonas aeruginosa genome with two-step allelic exchange.

Allelic exchange is an efficient method of bacterial genome engineering. This protocol describes the use of this technique to make gene knockouts and knock-ins, as well as single-nucleotide insertions, deletions and substitutions, in Pseudomonas aeruginosa. Unlike other approaches to allelic exchange, this protocol does not require heterologous recombinases to insert or excise selective markers from the target chromosome.

Oligoribonuclease is a central feature of cyclic diguanylate signaling in Pseudomonas aeruginosa.

The second messenger cyclic diguanylate (c-di-GMP) controls diverse cellular processes among bacteria. Diguanylate cyclases synthesize c-di-GMP, whereas it is degraded by c-di-GMP-specific phosphodiesterases (PDEs). Nearly 80% of these PDEs are predicted to depend on the catalytic function of glutamate-alanine-leucine (EAL) domains, which hydrolyze a single phosphodiester group in c-di-GMP to produce 5'-phosphoguanylyl-(3',5')-guanosine (pGpG).