Antimicrobial susceptibility testing in 90 min by bacterial cell count monitoring

Clin Microbiol Infect. 2013 Mar;19(3):286-91. doi: 10.1111/j.1469-0691.2012.03800.x. Epub 2012 Mar 5.


The rise in antimicrobial resistance has become a serious global health problem. Restrictive use of antibiotics seems the only option to temper this accession since research in new antibiotics has halted. Antimicrobial stewardship programmes rely on quick access to susceptibility data. This study evaluated the concept of bacterial cell count monitoring as a fast method to determine susceptibility. Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus strains were tested for amoxicillin/piperacillin and gentamicin by three conventional methods (VITEK2(®) , Etest(®) and broth-macrodilution). Bacterial cell count monitoring reliably predicted susceptibility after 90 min for Escherichia coli and after 120 min for Pseudomonas aeruginosa and Staphylococcus aureus without any minor, major or very major discrepancies. Time-to-result was reduced by 74%, 83% and 76%, respectively. Bacterial cell count monitoring shows great potential for rapid susceptibility testing.

Publication types

  • Evaluation Study

MeSH terms

  • Amoxicillin / pharmacology
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Load / methods*
  • Escherichia coli / drug effects*
  • Escherichia coli / growth & development
  • Gentamicins / pharmacology
  • Humans
  • Microbial Sensitivity Tests / methods
  • Piperacillin / pharmacology
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / growth & development
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / growth & development
  • Time Factors


  • Anti-Bacterial Agents
  • Gentamicins
  • Amoxicillin
  • Piperacillin