Induction of Acquired Resistance in Guinea Pigs with Defatted Mycobacterium Tuberculosis Vaccines.

Smith, D. W. (University of Wisconsin, Madison), G. B. Fregnan, L. DeLaquerriere-Richardson, and E. Valdivia. Induction of acquired resistance in guinea pigs with defatted Mycobacterium tuberculosis vaccines. J. Bacteriol. 88:87-92. 1964.-Residues of mycobacteria exhaustively extracted with neutral organic solvents have been shown to produce a level of resistance against tuberculosis in guinea pigs comparable to that produced by BCG. Disruption of defatted tubercle bacilli in adjuvant eliminated the acid-fast staining property of the residue, but immunizing and sensitizing properties were retained in the fraction which sedimented at 44,000 x g. To demonstrate these activities with 50 mug of vaccine, it was necessary to use Bayol-Arlacel adjuvant. A similar quantity of vaccine given in saline was inactive. A defatted vaccine prepared from a virulent strain of Mycobacterium tuberculosis recently passed through a guinea pig was significantly more immunogenic than a similar vaccine prepared from H37Ra.