THE ROLE OF PENICILLIN-INDUCED BACTERIAL VARIANTS IN EXPERIMENTAL PYELONEPHRITIS

Abstract

Determining the relation of spheroplasts, protoplasts, and L-forms, henceforth called bacterial variants, to human infection is exceedingly difficult because the parent organism is frequently isolated concomitantly with the variant. Therefore, in order to relate variants to disease in the host, they must be isolated unaccompanied by classical bacteria, preferably in the absence of antibiotic therapy, indicating that the variant alone is capable of inducing disease. Whether this occurs in renal infections in man is not known. This report deals with the role of apparently stable Escherichia coli variants in experimental pyelonephritis in rats. Stable variants of E. coli 06 induced with penicillin were used to produce experimental pyelonephritis in rats. Infection did not occur unless reversion to the parent form took place. The implications of this observation are discussed briefly.