Agreement assessment of tigecycline susceptibilities determined by the disk diffusion and broth microdilution methods among commonly encountered resistant bacterial isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2008 to 2010

Antimicrob Agents Chemother. 2012 Mar;56(3):1414-7. doi: 10.1128/AAC.05879-11. Epub 2011 Dec 12.

Abstract

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, initiated in 2006, is a nationwide surveillance program designed to longitudinally monitor the in vitro activity of tigecycline against commonly encountered drug-resistant bacteria. This study compared the in vitro activity of tigecycline against 3,014 isolates of clinically important drug-resistant bacteria using the standard broth microdilution and disk diffusion methods. Species studied included methicillin-resistant Staphylococcus aureus (MRSA; n = 759), vancomycin-resistant Enterococcus faecium (VRE; n = 191), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 602), ESBL-producing Klebsiella pneumoniae (n = 736), and Acinetobacter baumannii (n = 726) that had been collected from patients treated between 2008 and 2010 at 20 hospitals in Taiwan. MICs and inhibition zone diameters were interpreted according to the currently recommended U.S. Food and Drug Administration (FDA) criteria and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The MIC(90) values of tigecycline against MRSA, VRE, ESBL-producing E. coli, ESBL-producing K. pneumoniae, and A. baumannii were 0.5, 0.125, 0.5, 2, and 8 μg/ml, respectively. The total error rates between the two methods using the FDA criteria were high: 38.4% for ESBL-producing K. pneumoniae and 33.8% for A. baumannii. Using the EUCAST criteria, the total error rate was also high (54.6%) for A. baumannii isolates. The total error rates between these two methods were <5% for MRSA, VRE, and ESBL-producing E. coli. For routine susceptibility testing of ESBL-producing K. pneumoniae and A. baumannii against tigecycline, the broth microdilution method should be used because of the poor correlation of results between these two methods.

Publication types

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

MeSH terms

  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / growth & development
  • Anti-Bacterial Agents / pharmacology*
  • Carbapenems / pharmacology
  • Drug Resistance, Bacterial*
  • Enterococcus faecium / drug effects
  • Enterococcus faecium / growth & development
  • Enterococcus faecium / isolation & purification
  • Escherichia coli / drug effects
  • Escherichia coli / growth & development
  • Escherichia coli / isolation & purification
  • Gram-Negative Bacteria / drug effects*
  • Gram-Negative Bacteria / growth & development
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Positive Bacteria / drug effects*
  • Gram-Positive Bacteria / growth & development
  • Gram-Positive Bacteria / isolation & purification
  • Humans
  • Klebsiella pneumoniae / drug effects
  • Klebsiella pneumoniae / growth & development
  • Klebsiella pneumoniae / isolation & purification
  • Longitudinal Studies
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / growth & development
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Microbial Sensitivity Tests
  • Minocycline / analogs & derivatives*
  • Minocycline / pharmacology
  • Taiwan
  • Tigecycline
  • Vancomycin / pharmacology
  • beta-Lactamases / biosynthesis

Substances

  • Anti-Bacterial Agents
  • Carbapenems
  • Vancomycin
  • Tigecycline
  • beta-Lactamases
  • Minocycline