TABLE 2.

Coresistance of carbapenem-resistant isolates to β-lactam and non-β-lactam antibiotics

Antibiotic or resistance phenotype% of resistant isolates among:Statistical significance (P)
Carbapenem-susceptible isolates (n = 1,014)cCarbapenem-resistant isolates (n = 236)c
Ticarcillin1134<0.001
Piperacillin928<0.001
Piperacillin-tazobactam624<0.001
Ceftazidime1146<0.001
Cefepime1452<0.001
Aztreonam1953<0.001
Gentamicin2659<0.001
Amikacin919<0.001
Tobramycin944<0.001
Ciprofloxacin2553<0.001
Ofloxacin3268<0.001
Imipenem95d
Meropenem68
MDRa46
Panresistantb4
  • a MDR isolates are resistant to at least three of the following four antibiotics: ceftazidime, imipenem, tobramycin, and ciprofloxacin (27).

  • b Panresistant, resistant to all antibiotics tested.

  • c The percentages of resistant isolates shown include isolates in the intermediate and resistant CLSI categories (5).

  • d The remaining 5% of strains were imipenem susceptible, and the MIC of meropenem for these strains was 8 μg/ml (CLSI intermediate category).