Glycerol metabolism impacts biofilm phenotypes and virulence in via the Entner-Doudoroff pathway.

is a ubiquitous bacterium and a notorious opportunistic pathogen that forms biofilm structures in response to many environmental cues. Biofilm formation includes attachment to surfaces and the production of the exopolysaccharide Pel, which is present in both the PAO1 and PA14 laboratory strains of . Biofilms help protect bacterial cells from host defenses and antibiotics and abet infection.

Temporal σ stress-response profiles impact fitness.

Unlabelled: The Gram-positive model organism responds to environmental stressors by activating the alternative sigma factor σ. The sensing apparatus upstream of σ activation is thought to consist of cytoplasmic stressosomes-megadalton-sized protein complexes that include five paralogous proteins known as RsbRs. The RsbRs are presumed to be involved in stress sensing and the subsequent response.

A putative lipase affects biofilm matrix production.

is an opportunistic pathogen that is widely known for infecting patients with underlying conditions. This species often survives antibiotic therapy by forming biofilms, in which the cells produce a protective extracellular matrix. also produces virulence factors that enhance its ability to cause disease.

An Amino Acid Substitution in Elongation Factor EF-G1A Alters the Antibiotic Susceptibility of Pseudomonas aeruginosa LasR-Null Mutants.

The opportunistic bacterium Pseudomonas aeruginosa uses the LasR-I quorum-sensing system to increase resistance to the aminoglycoside antibiotic tobramycin. Paradoxically, -null mutants are commonly isolated from chronic human infections treated with tobramycin, suggesting there may be a mechanism that permits the emergence of -null mutants under tobramycin selection. We hypothesized that some other genetic mutations that emerge in these isolates might modulate the effects of -null mutations on antibiotic resistance.

PtsN in Pseudomonas aeruginosa Is Phosphorylated by Redundant Upstream Proteins and Impacts Virulence-Related Genes.

The bacterial nitrogen-related phosphotransfer (PTS; here, Nitro-PTS) system bears homology to well-known PTS systems that facilitate saccharide import and phosphorylation. The Nitro-PTS comprises an enzyme I (EI), PtsP; an intermediate phosphate carrier, PtsO; and a terminal acceptor, PtsN, which is thought to exert regulatory effects that depend on its phosphostate. For instance, biofilm formation by Pseudomonas aeruginosa can be impacted by the Nitro-PTS, as deletion of either or suppresses Pel exopolysaccharide production and additional deletion of elevates Pel production.