Action of Polyene Macrolide Antibiotics on Protoplast Type L-form of E. Coli

Abstract

Polyene macrolide antibiotics are known to exhibit biological activity against fungi and other eukarytic organisms, but not against bacteria These antibiotics cause permeability alterations in sensitive cells which lead to the loss of cytoplasmatic constituents culminating in cell death. The selective toxicity of polyene antibiotics is due to interaction with a unique component, a sterol, in the membranes of sensitive organisms. The natural resistance of bacteria on the other hand is generally explained by the absence of sterols in the bacterial cell membranes. In contrast to results of other investigators we found a real antibacterial activity with several polyene antibiotics by using the stable protoplast type L-form of E. coli W1655F⁺ as a test organism.