Action of Erythromycin on "Protoplasts" in vivo

Abstract
Bacteria may persist in "protoplast" form in kidneys after treatment of experimental enterococcal pyelonephritis with penicillin. Erythromycin, while ineffective against the bacterial form of infection, was able to kill "protoplasts" in vivo. This finding is consistent with the hypothesis that intact cell wall interferes with the ingress of erythromycin into the cellular area in which it acts.