Persisters: A Distinct Physiological State of E. Coli

BMC Microbiol. 2006 Jun 12;6:53. doi: 10.1186/1471-2180-6-53.

Abstract

Background: Bacterial populations contain persisters, phenotypic variants that constitute approximately 1% of cells in stationary phase and biofilm cultures. Multidrug tolerance of persisters is largely responsible for the inability of antibiotics to completely eradicate infections. Recent progress in understanding persisters is encouraging, but the main obstacle in understanding their nature was our inability to isolate these elusive cells from a wild-type population since their discovery in 1944.

Results: We hypothesized that persisters are dormant cells with a low level of translation, and used this to physically sort dim E. coli cells which do not contain sufficient amounts of unstable GFP expressed from a promoter whose activity depends on the growth rate. The dim cells were tolerant to antibiotics and exhibited a gene expression profile distinctly different from those observed for cells in exponential or stationary phases. Genes coding for toxin-antitoxin module proteins were expressed in persisters and are likely contributors to this condition.

Conclusion: We report a method for persister isolation and conclude that these cells represent a distinct state of bacterial physiology.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism
  • Colony Count, Microbial
  • Drug Resistance, Multiple, Bacterial*
  • Drug Tolerance
  • Escherichia coli / cytology
  • Escherichia coli / growth & development
  • Escherichia coli / isolation & purification
  • Escherichia coli / physiology*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Flow Cytometry / methods*
  • Gene Expression Regulation, Bacterial*
  • Genome, Bacterial
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Oligonucleotide Array Sequence Analysis / methods*
  • Promoter Regions, Genetic

Substances

  • Anti-Bacterial Agents
  • Bacterial Toxins
  • Escherichia coli Proteins
  • Green Fluorescent Proteins