^8 LOCAL TLSSUE REACTIVITY 



xaiicd in poteiu) in ihc range lioni 50 to i^'^oo reading units per 

 1 ( .( . Certain strains which were typical B. coli isohited from 

 urine and stool, yielded more active preparations than others. 

 Moreover, various batches derived from the same strains gave 

 preparations of varying potency. 



Apitz (iQ^g/;) employed for preparation of "agar washings" 

 filtrates several strains of B. coli isolated from cases of cystitis. 

 His preparations never gave intense hemorrhagic reactions. The 

 aboxe mentioned extreme fluctuations in potency of active prin- 

 ciples, partially depending on the strain employed, may have been 

 responsible for the weak reactions obtained by Apitz. 



ACTIVE PRINCIPLES OF B. FRIEDI.ANDER 



For these experiments B. jriedUuider of certain serological 

 groii})s Avere used. 



In 1926 Julianelle (19,^^0) classified B. jriedldnder by the im- 

 miuiological reacticjns of agglutination, agglutinin absorption, and 

 passive protection against infection into three specific types, A, 

 B and C. These types comprised the great majority of strains and 

 the remaining cultines were included in a heterogeneous group. 

 The carfjohydrate or solidjle specific substance was shown to be 

 chemically different for each of the three types. Julianelle re- 

 ported the following statistical data resulting from a study of 80 

 strains: A — 52 per cent, mostly human infections; B — 15 per cent, 

 animal soince; C — 9 per cent; x — 24 per cent. 



In my experiments plain broth cultures of B. jriedldnder, A 

 and C \vere incubated for three days and after centrifugalization, 

 filtered through Berkefeld "V" candles. Strain A filtrates con- 

 tained approximately 10 reacting units per i c.c. whilst strain C 

 yielded a filtrate containing 50 reacting" units per 1 c.c. The 

 reactions were severe and obtained in a high percentage of rab- 

 bits tested. Apitz (1935^-') obtained active principles of Fried- 

 lander bacillus in "agar washings" filtrates. It appears from his 

 description that the filtrates were of a comparati\ely low potency. 



ACTIVE PRINCIPLES OF B. DVSENTERIAE 



Filtrates of "Agar washings" and broth cultmes of variotis 

 strains of B. dysenteriae possess active principles (Shxvartzman, 

 1928/^) . On one occasion the filtrate of a Sonne strain contained 

 as many as 1500 reacting iniits, per 1 c.c. Recently Schneierson, in 

 these laboratories, tested a large group of B. dysenteriae Shiga 



