Table 6.

Results of comparison between Wider system susceptibility testing results and reference broth microdilution MIC for isolates of the family Enterobacteriaceae with known β-lactam resistance mechanismsa

Primary resistance mechanismb% Essential agreement% Errors
miMVM
Chromosomal AmpC β lactamase (176)97.71.00.00.0
Chromosomal class A β-lactamase (64)89.17.12.76.2
Broad-spectrum and IRT β-lactamases (168)97.64.10.00.0
Extended-spectrum β-lactamase (328)92.33.52.00.8
Permeability mutant (64)98.43.70.00.0
 Total (800)94.83.61.00.8
  • a Abbreviations: mi, minor error; M, major error; VM, very major error.

  • b Values in parentheses are the number of organism-antimicrobial agent combinations tested.