REACTIVITY TO VARIOUS MICROORGANISMS 39 



j)reparati()ns. "Agar washings" filtrates contained 150 reacting 

 imits per 1 c.c, and egg albumin broth culture filtrates prepared 

 according to the method of Olitskv and Kligler (1920) , contained 

 150 reacting luiits per 1 c.c. Endotoxin also ])repared according to 

 the method of Olitsky was active in dilution 1:150. 



Burnet (1931) elicited the phenomenon of local skin reac- 

 tivity to B. dysenteriae with autolyzed preparations of Besredka. 

 Thus far, it remains unknown, however, whether there exist 

 any differences in the phenomenon-producing potency of the 

 various strains of B. dysenteriae. 



AitofT, Dion and Dobkevitch (19360) reproduced the phenom- 

 enon with active principles derived from a strain of B. dysenteriae 

 of the new-born recently described by them. The preparations 

 tested were as follows: (1) a suspension in distilled water of a 

 twenty-four hour old agar culture left at room temperature for 

 six days and then filtered through a Chamberlain L3 filtrate 

 ("lysate") ; and (2) a filtrate of a fifteen day old culture in 

 Ramon's medium ("toxin") . The phenomenon could be elicited 

 when the "lysate" was used for both skin-preparatory and provoc- 

 ative injections; \vhen the preparatory injection of "toxin" Avas 

 followed by the provocative injection of "lysate"; ^vhen a pre- 

 paratory injection of B. coli culture filtrate was followed by 

 provocative injection of "lysate"; and when the preparatory in- 

 jection of "lysate" was followed by the intravenous injection of 

 "toxin." \V'hen "toxin" was used for both preparatory and provoc- 

 ati\'e injections no reactions ^vere obtained. 



ACTIVE PRINCIPLES OF B. PRODIGIOSUS 



According to Bertarelli (1903) some strains of B. prodigiosus 

 may exhibit considerable virulence. Aitoff, Dion and Dobkevitch 

 (1936&) isolated from the sputum of a case of pneumonia B. 

 prodigiosus pathogenic for mice, rats, guinea pigs and rabbits. 

 This strain induced septicemia and the organism could be re- 

 covered from the heart's blood of an injected mouse. "Lysates" 

 and "toxins" prepared according to the method described by these 

 authors in connection with their Av-ork on B. dysenteriae, elicited 

 the phenomenon. The lesions obtained with the "lysates" were 

 circumscribed whilst the "toxins" gave very prompt and diffuse 

 reactions. In one instance petechiae appeared almost immediately 

 after the intravenous injection was completed. 



