6o LOCAL TISSUE REACTIVITY 



RFCAPl'IliLATION 



The actixc priiuij^les of the phenomenon were thus far ob- 

 tained with \arying degrees of success from a large number of 

 microorganisms. 



Some bacteria yield under sinijDle conditions of cultivation 

 ("agar washings" culture filtrates and broth culture filtrates) ac- 

 tive principles of considerable potency. Among these are meningo- 

 coccus, B. typhosus, B. paratyphosus, B. coli, B. jriedldnder, B. 

 dysenleriae, B. prodigiosus, members of hemorrhagic septicemia 

 and hemoglobinophilic groups (B. Icpiseplicus, B. pestis, B. in- 

 fluenzae , B. pertussis) , and Vibrio cholerae. The concentrations 

 of preparatory and reacting factors do not necessarily run parallel. 

 Thus, filtrates of certain strains of B. typhosus ordinarily contain 

 as many as 150 to 200 jireparatory units and 300 to 500 reacting 

 units. Conversely, meningococcus Group III yields preparations 

 containing rarely more than 50 preparatory units with as many 

 as 2000 to 3000 reacting imits. 



Many bacteria produce the principles in low and variable con- 

 centration. Among these are pneiunococci, streptococci, B. tuber- 

 eulosis, B. melitensis, B. abortus, staphylococci, anaerobic gram- 

 negative bacilli isolated from chronic limg abscesses and Spiro- 

 cheta pallida (p. 72) . The activity of the preparations of this group 

 is best demonstrated ^vhen tested in rabbits prepared ^vith heterol- 

 ogous fdtrates of high potency because most of them may be 

 totally devoid of preparatory potency. 



Potent active principles were also obtained from Ascaris lum- 

 bricoidis. The ability of yeast, ricin and diphtheria toxin to elicit 

 the phenomenon remains questionable. 



