A new principle in isolation of spirochetes in pure culture

Abstract

In attempting to obtain pure cultures of spirochetes from the lesions of rabbits showing symptoms of generalized lues, I was confronted with extreme difficulties in the case of two strains especially—one on the eyebrow of a rabbit infected by the intravenous inoculation of syphilitic blood and the other deriving from the condyloma on the vagina of a rabbit infected by coitus from a male rabbit having specific lesion on the prepuce. The bacterial contamination in each case was so abundant, that numerous attempts at purification using original Noguchi method failed for months. Having noticed earlier 1 that certain antiseptics in proper quantities exert a marked accelerating action upon the growth of spirochetes, I prepared media containing salvarsan in very small amounts and finally after 10 passages succeeded in isolating both strains of spirochetes, which apparently have remained pure for the last five months. In another series of experiments I tried to make use of the fact that anilin dyes, which exert marked sterilizing action on bacteria even in dilutions of 1: 5,000 and 1 : 10,000, seem not to inhibit the growth of certain spirochetes in much greater concentrations. 2 The experiments in this direction are still not completed, as so far it was impossible to find a dye which would uniformly inhibit the growth of all the bacteria occurring in contaminated syphilitic material in a concentration which would allow the life of all the different strains of spirochetes.