ESKAPE pathogens rapidly develop resistance against antibiotics in development in vitro.

Despite ongoing antibiotic development, evolution of resistance may render candidate antibiotics ineffective. Here we studied in vitro emergence of resistance to 13 antibiotics introduced after 2017 or currently in development, compared with in-use antibiotics. Laboratory evolution showed that clinically relevant resistance arises within 60 days of antibiotic exposure in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, priority Gram-negative ESKAPE pathogens.

Evolution and ecology of anti-defence systems in phages and plasmids.

Prokaryotes (Bacteria and Archaea) encode a highly diversified arsenal of defence systems that protect them against mobile genetic elements, such as phages and plasmids. In turn, mobile genetic elements encode anti-defence systems that allow them to escape the activity of these defence systems. This has resulted in an evolutionary arms race in which defence systems and anti-defence systems evolve and adapt continuously, driving intriguing innovation and enormous diversification on both sides.

Multi-layered genome defences in bacteria.

Bacteria have evolved a variety of defence mechanisms to protect against mobile genetic elements, including restriction-modification systems and CRISPR-Cas. In recent years, dozens of previously unknown defence systems (DSs) have been discovered. Notably, diverse DSs often coexist within the same genome, and some co-occur at frequencies significantly higher than would be expected by chance, implying potential synergistic interactions.

CRISPR-Cas in Pseudomonas aeruginosa provides transient population-level immunity against high phage exposures.

The prokaryotic adaptive immune system, CRISPR-Cas (clustered regularly interspaced short palindromic repeats; CRISPR-associated), requires the acquisition of spacer sequences that target invading mobile genetic elements such as phages. Previous work has identified ecological variables that drive the evolution of CRISPR-based immunity of the model organism Pseudomonas aeruginosa PA14 against its phage DMS3vir, resulting in rapid phage extinction. However, it is unclear if and how stable such acquired immunity is within bacterial populations, and how this depends on the environment.