Hormesis in high-throughput screening of antibacterial compounds in E coli

Hum Exp Toxicol. 2010 Aug;29(8):667-77. doi: 10.1177/0960327109358917. Epub 2010 Jan 12.


This article assesses the response below a toxicological threshold for 1888 antibacterial agents in Escherichia coli, using 11 concentrations with twofold concentration spacing in a high-throughput study. The data set had important strengths such as low variability in the control (2%-3% SD), a repeat measure of all wells, and a built-in replication. Bacterial growth at concentrations below the toxic threshold is significantly greater than that in the controls, consistent with a hormetic concentration response. These findings, along with analyses of published literature and complementary evaluations of concentration-response model predictions of low-concentration effects in yeast, indicate a lack of support for the broadly and historically accepted threshold model for responses to concentrations below the toxic threshold.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / standards
  • Anti-Bacterial Agents / toxicity*
  • Dose-Response Relationship, Drug
  • Escherichia coli / drug effects*
  • Maximum Tolerated Dose
  • Microbial Sensitivity Tests*
  • No-Observed-Adverse-Effect Level


  • Anti-Bacterial Agents