Error rates for imipenem, meropenem, and ertapenem with the Wider system and Etest compared with the results of the broth microdilution reference methoda for the 18 VIM-1-producing K. pneumoniae isolates

Test methodNo. (%) of errors for:
Imipenem Meropenem Ertapenem
Minor (n = 18)bMajor (n = 0)Very major (n = 18)Minor (n = 18)Major (n = 4)Very major (n = 4)Minor (n = 18)Major (n = 0)Very major (n = 18)
Etest6 (33)05 (28)11 (61)03 (75)1 (6)00
Wider006 (33)10 (56)1 (25)1 (25)NAc NANA
  • a According to the CLSI (3, 4).

  • b n, denominator used for calculating error rates, based on broth microdilution results. Denominators are the total number of isolates tested (minor error rate), the number of susceptible isolates (major error rate), and the number of resistant isolates (very major error rate).

  • c NA, not available.