Extreme Antibiotic Persistence via Heterogeneity-Generating Mutations Targeting Translation

Area of Science:

• Microbiology
• Evolutionary Biology
• Genetics

Background:

• Antibiotic persistence is a non-heritable bacterial tolerance to antibiotics, posing clinical challenges.
• Increased persistence rates (hyperpersistence) are observed in chronic infections, suggesting evolutionary adaptation.
• Mechanisms driving bacterial hyperpersistence remain largely uncharacterized.

Purpose of the Study:

• To investigate the evolutionary pathways leading to increased antibiotic persistence rates.
• To identify genetic mutations and cellular states associated with hyperpersistence in Escherichia coli.
• To develop methods for isolating and characterizing hyperpersistent bacterial subpopulations.

Main Methods:

• Laboratory evolution experiments were used to select for hyperpersistent Escherichia coli mutants.
• Genetic analysis focused on identifying mutations in evolved populations.
• Transcriptional profiling and gene expression analysis were performed to understand cellular states.
• Methods were developed to isolate subpopulations with extreme persistence phenotypes.

Main Results:

• Laboratory evolution increased persistence rates by orders of magnitude in multiple independent Escherichia coli populations.
• Mutations conferring hyperpersistence were significantly enriched in translation-related genes.
• Distinct adaptive mutations converged on transcriptional changes, including increased gene expression heterogeneity.
• Isolation of subpopulations with a substantial fraction of persister cells was achieved.

Conclusions:

• Experimental evolution is a viable strategy to generate and study hyperpersistent bacterial mutants.
• Translation-related genes are critical targets for the evolution of antibiotic hyperpersistence.
• Induced population heterogeneity in gene expression is a key feature of hyperpersistence.
• Hyperpersister mutants provide a platform for molecular characterization and the development of antipersistence strategies.