Hypermutability bypasses genetic constraints in SCV phenotypic switching in Pseudomonas aeruginosa biofilms.

Biofilms are critical in the persistence of Pseudomonas aeruginosa infections, particularly in cystic fibrosis patients. This study explores the adaptive mechanisms behind the phenotypic switching between Small Colony Variants (SCVs) and revertant states in P. aeruginosa biofilms, emphasizing hypermutability due to Mismatch Repair System (MRS) deficiencies.

Rhythms in lipid droplet content driven by a metabolic oscillator are conserved throughout evolution.

The biological clock in eukaryotes controls daily rhythms in physiology and behavior. It displays a complex organization that involves the molecular transcriptional clock and the redox oscillator which may coordinately work to control cellular rhythms. The redox oscillator has emerged very early in evolution in adaptation to the environmental changes in O levels and has been shown to regulate daily rhythms in glycerolipid (GL) metabolism in different eukaryotic cells.

Membrane-targeted mechanism for amphiphilic vitamin C compounds as methicillin-resistant Staphylococcus aureus biofilm eradicating agents.

Staphylococcus aureus infections and its biofilm removal is an important concern in health care management. Methicillin-resistant S. aureus is responsible for severe morbidity and mortality worldwide.

Longitudinal Evolution of the Pseudomonas-Derived Cephalosporinase (PDC) Structure and Activity in a Cystic Fibrosis Patient Treated with β-Lactams.

Traditional studies on the evolution of antibiotic resistance development use approaches that can range from laboratory-based experimental studies, to epidemiological surveillance, to sequencing of clinical isolates. However, evolutionary trajectories also depend on the environment in which selection takes place, compelling the need to more deeply investigate the impact of environmental complexities and their dynamics over time. Herein, we explored the within-patient adaptive long-term evolution of a Pseudomonas aeruginosa hypermutator lineage in the airways of a cystic fibrosis (CF) patient by performing a chronological tracking of mutations that occurred in different subpopulations; our results demonstrated parallel evolution events in the chromosomally encoded class C β-lactamase ().

Modular (de)construction of complex bacterial phenotypes by CRISPR/nCas9-assisted, multiplex cytidine base-editing.

CRISPR/Cas technologies constitute a powerful tool for genome engineering, yet their use in non-traditional bacteria depends on host factors or exogenous recombinases, which limits both efficiency and throughput. Here we mitigate these practical constraints by developing a widely-applicable genome engineering toolset for Gram-negative bacteria. The challenge is addressed by tailoring a CRISPR base editor that enables single-nucleotide resolution manipulations (C·G → T·A) with >90% efficiency.