Agar diffusion tests with cefuroxime disks for predicting ceftriaxone susceptibility among isolates of Streptococcus pneumoniae

Abstract

The performance of agar diffusion tests using disks of cefuroxime (30µg) for predicting ceftriaxone susceptibility in 33 isolates of Streptococcus pneumoniae was studied. All 7 resistant isolates to ceftriaxone (MIC ³1.0 µg/ml) exhibited zones of inhibition <28mm. The procedure can be easily adapted to clinical laboratories.