IN-VITRO ACTIVITY OF CEFTIZOXIME, CEFTAZIDIME, CEFUROXIME, CEFTRIAXONE, CEFOTAXIME, AND PENICILLIN AGAINST STREPTOCOCCUS-PNEUMONIAE AS DETERMINED BY 3 QUANTITATIVE METHODS

E-test, broth microdilution, and agar dilution susceptibility tests we re used to evaluate penicillin and five extended-spectrum cephalospori ns against 196 strains of Streptococcus pneumoniae with different leve ls of penicillin resistance. Oxacillin disk tests corresponded to mini mum inhibitory concentrations of penicillin determined by the E-test b etter than those generated by broth microdilution or agar dilution met hods. Relative potency of the study drugs was as follows: cefotaxime=c eftriaxone > penicillin > cefuroxime > ceftizoxime > ceftazidime.