TABLE 1.

Results of the EPI test carried out with 190 P. aeruginosa strains

MBL production (no. of strains)MBL type (no. of strains)Phenotype (no. of strains)cMIC (μg/ml) ford:No. of strains showing a MIC reduction of:
IMPcEPI>128-fold128-fold64-fold32-fold16-fold8-fold4-fold2-fold0
Negative (168)Imps Cazs (2)a212
Imps Cazr (5)2-41-414
Impr-i Cazr-i (161)8-642-321410353
Positive (22)bVIM-1 (7)Impr Cazr128-2560.5-16115
VIM-2 (10)Impr Cazr32-5121-821421
VIM-3 (1)Impr Cazr6421
IMP-1 (1)Impr Cazr512161
IMP-2 (3)Impr Cazr128-2568-32111
  • a Including the P. aeruginosa reference strains PAO-1 and ATCC27853.

  • b Including strains from references 3, 5, 6, and 15 to 17.

  • c Phenotypes listed indicate levels of susceptibility to the drugs imipenem (Imp) and ceftazidime (Caz). The superscript letters indicate the following: s, sensitivity, r, resistance; and r-i, resistance to intermediate susceptibility.

  • d Where a single value is not listed, the MIC range is given. IMP, imipenem; EPI, EDTA-phenanthroline-imipenem.