Tuberculosis in Guinea-Pigs After Treatment with Tubercle Bacilli Made Non-Acidfast with Oleic Acid

Abstract

In experiments previously reported by the author ' it was determined that dehydrated bacilli suspended in oleic acid or in olive oil lose their acidfastness when placed in the incubator. ' Killed bacilli did not undergo the change. Loss of acidfastness took place most rapidly at 37 C. with an abrupt cessation at lower temperatures, when the metabolic activities of the bacilli were greatly reduced. At temperatures above 37 C. which approached the thermal deathpoint of the cultures the bacilli were affected but little. Under the conditions of these experiments, living cultures were regarded as necessary for the removal of acidfastness. Since the publication of these experiments, it has been found that the discharge of acidfastness can be accomplished without dehydration and suspension of the dehydrated bacilli in the oily medium. The purpose of this paper is to describe a procedure for rendering cultures in aqueous-alcohol suspensions nonacidfast by means of oleic acid, and to describe the tuberculosis of guinea-pigs treated with the liquid containing all substances removed from the bacilli during the removal of the acidfastness as well as the suspended nonacidfast bacilli. Treatment with the non-acidfast bacilli alone appears not to be effective in increasing the resistance of guinea-pigs to tuberculosis when subsequently inoculated with living bacilli.