Comparison of Etest, agar dilution, broth microdilution and disk diffusion methods for testing in vitro activity of levofloxacin against Staphylococcus spp. isolated from neutropenic cancer patients

Int J Antimicrob Agents. 2002 Feb;19(2):147-54. doi: 10.1016/s0924-8579(01)00483-6.


The susceptibility to levofloxacin of 194 consecutive staphylococcal (45 Staphylococcus aureus and 149 coagulase-negative staphylococci) isolates from neutropenic patients was determined by Etest and the results compared with those obtained using NCCLS-methods (broth microdilution, agar dilution and disk diffusion). Overall agreement at +/- 1log(2) dilution for Etest compared with broth microdilution and agar dilution was 99.0 and 83.5%, respectively. The Etest category agreement with broth microdilution and disk diffusion was 95.9 and 89.7%, respectively. Comparison of categories with Etest and agar dilution method gave only 67.0% absolute categorical agreement, with 29.9% minor errors and 10.7% major errors. No very major errors occurred by the four methods tested. Our results show that Etest is a valid alternative to the reference NCCLS-methods for monitoring the clinical usefulness of levofloxacin against staphylococci isolates from neutropenic patients.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agar
  • Anti-Infective Agents / pharmacology
  • Culture Media
  • Diffusion
  • Drug Resistance, Microbial
  • Humans
  • Levofloxacin*
  • Microbial Sensitivity Tests / methods*
  • Neoplasms / complications
  • Neoplasms / microbiology*
  • Neutropenia / complications
  • Neutropenia / microbiology*
  • Ofloxacin / pharmacology*
  • Staphylococcus / drug effects*


  • Anti-Infective Agents
  • Culture Media
  • Levofloxacin
  • Agar
  • Ofloxacin