The Effect of “Tween 80” in Vitro on the Bacteriostatic Activity of Twenty Compounds for Mycobacterium tuberculosis

Abstract

"Tween 80" in a synthetic medium, as compared to the synthetic medium alone, increased the tuberculostatic activity of 15 out of 20 compounds, decreased the activity of 3 compounds, and had no effect on 2 compounds. Crystalline bovine albumin decreased the inhibition of growth of 13 out of the 20 compounds. In the Tween-albumin medium, 5 compounds were more bacteriostatic than in the basal medium, 4 gave approx. the same results in the 2 media, and the remaining 11 were less bacteriostatic than in the basal medium. In the presence of purified Tween 80, 7 of the 14 compounds were less bacteriostatic than in the presence of unpurified Tween 80. The remaining 7 compounds inhibited bacterial growth approx. the same amount in both media. The bacteriostatic activity of 12 of the 13 compounds was essentially the same in both the purified Tween-albumin medium and in the unpurified Tween-albumin medium. Decreasing the concn. of Tween 80 4-fold in the medium did not alter significantly the bacteriostatic levels of the 5 compounds tested. Under the conditions of the expt. the free oleic acid that may be present in Tween 80 apparently was not responsible for the effect of Tween 80 on the bacteriostatic activities.