Table 3.

Detection of β-lactamases among E. coliand K. pneumoniae isolates by various interpretive criteria applied to results obtained in tests with the N + 2 panel

Interpretive criterionaNo. of strains fulfilling interpretive criterion based upon type of β-lactamase
ESBL (n = 33)AmpC (n = 8)Other (n = 21)
Aztreonam ≥ 22770
Ceftazidime ≥ 23082
Ceftazidime ≥ 42980
Cefotaxime ≥ 42350
Ceftriaxone ≥ 42450
Ceftizoxime ≥ 42170
Cefotetan ≥ 8070
  • a Listed as MIC (in micrograms per milliliter) of antibiotic given.