Screening for betalactam resistance using Ceftazidime* 10 µg disk

SRGA breakpoints on ISA (Oxoid), semiconfluent inoculum, 18-20 h incubation, 36 C, ambient air:
For breakpoints, see the current zone diameter breakpoint table.

*To detect "all" ESBLs, use both cefotaxime and ceftazidime.

*Cefotaxime does not pick up all ESBL-enzymes. 
Further testing is needed to characterize enzymes.