title: Correlation of MIC value and disk inhibition zone diameters in clinical Legionella pneumophila serogroup 1 isolates.
abstract: OBJECTIVE
  Routine use of disk diffusion tests for detecting antibiotic resistance in Legionella pneumophila has not been described. The goal of this study was to determine the correlation of MIC values and inhibition zone diameter (MDcorr) in clinical L. pneumophila isolates.
  
  
  METHODS
  Inhibition zone diameter of 183 L. pneumophila clinical isolates were determined for ten antimicrobials. Disk diffusion results were correlated with MICs as determined earlier with E-tests.
  
  
  RESULTS
  Overall the correlation of MIC values and inhibition zone diameters (MDcorr) of the tested antimicrobials is good, and all antimicrobials showed a WT distribution. Of the tested fluoroquinolones levofloxacin showed the best MDcorr. All macrolides showed a wide MIC distribution and good MDcorr. The MDcorr for cefotaxim, doxycycline and tigecycline was good, while for rifampicin and moxifloxacin, they were not.
  
  
  CONCLUSIONS
  Overall good correlation between MIC value and disk inhibition zone were found for the fluoroquinolones, macrolides and cefotaxim.
authors.affiliation: Regional Laboratory of Public Health, Haarlem, The Netherlands. j.bruin@streeklabhaarlem.nl
authors.forename: Jacob P
authors.initials: JP
authors.lastname: Bruin
authors.forename: Bram M W
authors.initials: BM
authors.lastname: Diederen
authors.forename: Ed P F
authors.initials: EP
authors.lastname: Ijzerman
authors.forename: Jeroen W
authors.initials: JW
authors.lastname: Den Boer
authors.forename: Johan W
authors.initials: JW
authors.lastname: Mouton
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000494:pharmacology; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology; D006801:Humans; D016952:Legionella pneumophila / Q000187:drug effects* / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000382:microbiology*; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D018709:Statistics, Nonparametric
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D018942:Macrolides; D002439:Cefotaxime