Relationship of Type of Growth of M. tuberculosis to Antituberculous Activity of Subtilin

Abstract

The degree of inhibition of tubercle bacilli by subtilin in vitro parallels the degree of growth dispersion of the organisms. In a medium permitting diffuse growth, subtilin was highly active. Conversely, in a medium in which growth was clumped, whether because of omission of Tween or from antagonism of Tween by serum, no significant inhibition of growth by subtilin was demonstrable. When serum from rabbits injd. with subtilin was tested against tubercle bacilli in a medium containing sufficient Tween, the observed anti-tuberculous activity paralleled the activity against streptococci and staphylococci. If the amt. of Tween added to such tests was insufficient to produce diffuse growth of tubercle bacilli, subtilin activity was greatly diminished or absent.