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

The performance of agar diffusion tests using disks of cefuroxine (30 micrograms) for predicting ceftriaxone susceptibility in 33 isolates of "Streptococcus pneumoniae"was studied. All 7 resistant isolates to ceftriaxone (MIC>= 1.0 microgram/ml) exhibited zones of inhibition < 28 mm. The procedure can be easily adapted to clinical laboratories.