Growth of Small Numbers of Tubercle Bacilli, H37, in Long's Liquid Synthetic Medium and Some Interfering Factors

Abstract

The growth of the H37 strain of human tubercle bacilli in Long''s synthetic medium can develop when amts. at least as small as 10-7 to 10-8 mg. are planted. Growth may be inhibited, however, by very small amts. (< 1 ppm.) of certain organic substances[long dash]e.g., the soap, Na oleate, and the distillates from bleached, non-absorbent, cotton stoppers[long dash]which are readily adsorbed by the glassware. When such inhibitors are present the smallest amts. of these organisms which will grow vary from 102 to 106. The elimination of these inhibiting substances is important in cultural studies of this and other organisms, particularly when investigating accessory growth factors or inhibiting agents intentionally added to the media.