258 



Scientific Proceedings (115). 



132 (1714) 



Multiple infections with Treponema pallidum in the rabbit. 



By LOUISE PEARCE and WADE H. BROWN. 



[From the Rockefeller Institute, New York City.] 



Once it has been demonstrated that under appropriate con- 

 ditions superinoculation of a rabbit with an advanced syphilitic 

 infection may give rise to a typical primary lesion, 1 the question 

 naturally arises as to whether this second infection is limited in 

 its effects to the local reaction or is capable of further participation 

 in the disease produced. 



The problem was approached by a number of experiments. 

 Rabbits infected with strains of low virulence were reinoculated 

 with strains of high virulence after the original infection had be- 

 come well established. In general, the primary inoculation was 

 made in one or both testicles while the second was intracutaneous 

 on the sheath or at the base of one ear, using equivalent amounts 

 of a testicular emulsion. The infections thus produced were com- 

 pared with those in a series of control animals. The interpreta- 

 tion of the experimental results was based upon the usual course 

 of the disease produced by each strain with particular reference 

 to the type and severity of lesions and to their time and sequence 

 of occurrence since at a given time and under given conditions 

 these are comparatively constant properties of any given strain. 



The experiments up to the present time have yielded a number 

 of instances in which the nature of the infection differs from that 

 ordinarily seen with any one of the several strains employed and 

 this may be illustrated by citing a single example. The two strains 

 used in this experiment have been studied in a large series of 

 animals. The less virulent strain (III) used for the primary 

 inoculation was isolated in the fall of 1919. It has always pro- 

 duced a mild infection with slight primary lesions of short dura- 

 tion and generalized lesions of a minor character consisting of 

 occasional small diffuse or papular lesions of the skin, slight in- 

 filtrations about the sheath, a few cases of keratitis and two in- 



1 Brown, W. H., and Pearce, L., Proc. Soc. Exper. Biol, and Med., 1921, 

 xviii, 200. 



