The antimycobacterial activity of tissue extracts and surface-active agents in Dubos's medium.

Purified tissue enzyme preparations, particularly bovine pancreatic deoxyribonuclease, have been shown to inhibit specifically pathogenic strains of Mycobacterium tuberculosis. Destruction of the enzymic activity did not influence this effect. Inhibition in Dubos’s medium was markedly increased by Tween 80 but not by other surface active agents. Antibiotic potentiation by Tween 80 alone or combined with the tissue extracts was observed. The antimycobacterial activity of spermine was confirmed, but there was no evidence that it was present in our extracts and the inhibitory substance has not yet been identified.