Screening for betalactam resistance using Cefotaxime* 5 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

Further testing is needed to characterize enzymes.