TISSUE REACTIVITY 



Chapter I 

 INTRODUCTION 



BASIC EXPERIMENTS 



Phenomenon of local skin reactivity to bacterial filtrates: 



Tlie strains ol B. typhosus employed for the early experiments 

 were Tl and T040. They were obtained from the stool of con- 

 valescent typhoid fever patients one to four years prior to the 

 ^vork, respectively. Both strains appeared smooth and Avere agglu- 

 tinated by B. typhosus antisera to a high titer. The floccules Avere 

 large. The strain T040, ho"\vever, ^vas inagghuinable during the 

 first month of cultivation. 



The toxic substances ^vere prepared as follows: 



Two-hundred cubic centimeters of tryptic digest broth of 

 initial pH 7.8 were added to 2000 c.c. Erlenmeyer flasks to give 

 a large sinface area. The entire growth of one twenty-four hoiu' 

 old agar slant culture of B. typhosus was suspended in 10 c.c. 

 of 0.85 per cent NaCl solution. Ten cubic centimeters of the 

 suspension were added to each Erlenmeyer flask. The period of 

 incubation ^vas six days. The cultures were then filtered through 

 paper and cotton and finally through Berkefeld "V" candles. The 

 filtrates were tested for sterility, stored in the refrigerator and 

 used for a period of approximately t^vo to three ^veeks following 

 their preparation. No preservative was added. 



The entire skin of the abdomen of rabbits was epilated with 

 barium sidphide. The animals ^vere injected not less than tAventy- 

 four hours after shaving ^vhen no signs of irritation "were seen. 

 The local injections described belo^v were made intradermally. 

 Four sites, i.e., the upper and lower right and left quadrants of 

 the skin of the abdominal Avail, about 2 inches apart from each 

 other, Avere used for the injections. The amount of fluid injected 

 into each area Avas usually 0.25 c.c. 



I 



