Terramycin inhibition of gluconate oxidation by Escherichia coli.

The mode of action of "terramycin" (oxytetracycline, Pfizer), has not been described in detail, although numerous investigators have shown that the antibiotic exerts an inhibitory effect on oxidative mechanisms. Terramycin inhibition of the oxidation of Krebs cycle intermediates by Escherichia coli was rieported by Wong and Ajl (1953). Similarly, Ajl (1953) observed the terramycin inhibition of microbial oxidation of substrates which participate in terminal respiration. Glutamate oxidation inhibition was demonstrated by Karp and Snydei (1952), in murine and epidemic typhus rickettsiae. Terramycin and "aureomycin" were also shown to disrupt oxidative phosphorylation systems in rat mitochondria (Loomis, 1950). This study was initiated in an attempt to define the site of terramycin activity on oxidative reactions in Escherichia coli.