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
Chromosomal AmpC β lactamase (176)
Chromosomal class A β-lactamase (64)
Broad-spectrum and IRT β-lactamases (168)
Extended-spectrum β-lactamase (328)
Permeability mutant (64)
 Total (800)
  • 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.