Use of Penicillin MICs To Predict In Vitro Activity of Other β-Lactam Antimicrobial Agents against Streptococcus pneumoniae

Linear regression analysis was used to compare penicillin MICs determined with 3,129 recent clinical isolates of Streptococcus pneumoniae to MICs obtained with nine other beta-lactam antimicrobial agents. A strong correlation between penicillin MICs and those obtained with other beta-lactams was demonstrated. It may be possible to test penicillin and use MICs obtained with penicillin to predict MICs of other beta-lactam antimicrobials for Streptococcus pneumoniae.