Concentration of acid-fast bacilli with water-insoluble liquids

1. A study of the feasibility of the flotation method for concentrating acid-fast bacilli with water-insoluble, volatile liquids was conducted. 2. Commercial grade n-hexane, manufactured by the Phillips Petroleum Company, was found to have the characteristics of the desired solution. 3. The toxic effect shown by n-hexane was mild to M. phlei, M. smegmatis, BCG and H37Ra. 4. Shaking of he bacillary suspension produced toxic changes in BCG and H37R. M. phlei and M. smegmatis were not affected by the shaking with n-hexane. 5. Concentration of the bacilli into the n-hexane was achieved with shaking of the bacillary suspension with n-hexane. 6. When the suspension was shaken for 15 seconds and allowed to sit for 30 minutes before inoculation onto media, eugenic growth (5-7 mm) grew readily. When the suspensions were shaken vigorously for 10 minutes, the size and numbers of the colony diminished. 7. A presumptive diagram of the possible configuration of the tubercle bacilli and the saprophytes is presented. 8. A concept of the pathogenicity of the tubercle bacilli based upon an easter-esterase complex is suggested.