The Effect of Incompletely Inhibitory Concentrations of Penicillin on Escherichia coli

Abstract

In sediments of penicillin-treated patients appeared zygospore-like bodies which upon culturing on bacteriological media yielded Escherichia coli. Through expts. with a strain of E. coli in media containing incompletely inhibitory concs. of penicillin unusual forms of E. coli were observed. With 150 Oxford units penicillin per ml. of broth or McConkey agar forms similiar to those found in the urine sediments could be produced.