Characteristics of two broad spectrum antibiotics produced by Mycoplasma sp. RP III

Abstract

Two extracellular antibiotics produced by Mycoplasma sp. RP III growing in serum-containing media have been purified by solvent extraction and ion-exchange chromatography. Factor I inhibits Gram-positive and Gram-negative bacteria in vitro and a crude preparation protected mice from Pseudomonas and Straphylococcus infections; it is of low cytotoxicity. Factor II, a lipid, inhibits Gram-positive and Gram-negative bacteria, Candida species, and is as cytotoxic as the actinomycins.