46 LOCAL TLSSUE REACTIVITY 



is al)lc to ic;ut to the intravenous injection ol these substances 

 fioni other lunehited microorganisms. 



Reactions with live cultures of Streptococcus hemolyticus 

 scarlatinae: 



In the followino exj:)eriments the rabbits were given intrader- 

 mal injections of filtrates of B. typJiosus and twenty-foin^ hours 

 later they were given intravenous injections of cultmes of Strep- 

 tococcus hemolyticus scarlatinae prepared by various methods. 



Strain 4014 of Streptococcus hemolyticus scarlatinae was grown 

 in various fluid media for twenty-four hours and as such injected 

 intravenotisly into the prepared rabbits in a dose of 3 c.c. per kilo 

 of body weight. The fluid media were plain broth of pH 7.6, 

 plain broth of pH 7.6 containing various amounts of dextrose 

 (from 0.1 per cent to 2 per cent) , tryptic digest broth of pH 7.6 

 and tryptic digest broth containing various amotuits of dextrose 

 (from o. 1 per cent to 2 per cent) . The various cidtures were 

 made aerobically {i.e., 100 c.c. of fluid in a 500 c.c. Erlenmeyer 

 flask) , anaerobically {i.e., luider petrolatum seal) and partially 

 anaerobically {i.e., 100 c.c. of fluid in a 125 c.c. Erlenmeyer flask) . 

 Live broth cultmes ^vere able to elicit severe hemorrhagic necrosis 

 in the B. typhosus prepared skin sites. One hundred rabbits were 

 tested with these ctilttnes. Of these, 66 gave distinctly positive re- 

 actions, one a doubtful reaction and the remaining^ rabbits nesfa- 

 tive reactions. Examination of the individual groups of rabbits 

 did not demonstrate any obvious relationship between the mode 

 of cultivation and the resiUts obtained. Possibly, however, par- 

 tially anaerobic cultures in plain broth of pH 7.6 containing from 

 0.5 per cent to 1 per cent dextrose and incubated at 37.5^ c. for 

 twenty-four hours gave the best results. 



In an additional group of experiments there was compared the 

 reacting potency of live cultures of various strains of Streptococ- 

 cus Jiemolyticus grown in 1 per cent dextrose broth under partial 

 anaerobiosis at 37.5° c for twenty-foin- hotns. Marked differences 

 in reacting potency of strains '^vere noted. 



Reactions with toluene-killed cultures: supernatant fluid of 

 centrifuged cultures and filtrates of cultures of Streptococ- 

 cus hemolyticucss arlatinae: 



Experiments were made in order to determine ^vhether the 

 presence of live streptococci ^vas essential for the reacting potency 



