NOTE ON CROSS-AGGLUTINATION OF B. COLI 

 COMMUNIS AND B. DYSENTERIAE SHIGA^ 



I. J. KLIGLER 



From the Laboratories of the Rockefeller Institute for Medical Research, New York 



Received for publication December 24, 1917 



This note refers to an instance of cross-agglutination between 

 two distinct bacilli in immune sera, prepared for each, and in 

 practically identical end dilutions. 



Other similar instances of cross-agglutinations are reported 

 in the hterature, but with few exceptions either the agglutination 

 limit was less for the heterologous than for the homologous organ- 

 ism, or the cooperation of the two organisms in producing the 

 agglutinins could not be excluded. Thus Stern (1898) studied 

 five samples of blood serum from patients with typhoid fever 

 which agglutinated, equally with the typhoid bacilli, the cultures 

 of B. coli isolated from their stools. In this example, the possi- 

 bility exists that mixed infection with the colon bacilli coexisted. 

 Rodet (1897) found that sheep sera derived from animals im- 

 munized with B. typhosus and B. coli, respectively, agglutinated 

 the heterologous organism equally with "the homologous. Park 

 and Williams (1910) observed the serum of a horse immunized 

 with the Flexner dysenteric bacilli which agglutinated a culture 

 of B. coli in the same end dilutions (1 : 10,000) as the dysenteric 

 bacillus. Conversely, a goat immunized with the B. coli culture 

 yielded a serum of a titre of 1 : 5,000 for the B. coli and 1 : 3,000 for 

 Flexner B. dysenteriae. The chief interest of the following com- 

 munication arises from the fact that it concerns a similar cross- 

 agglutination of B. coli and B. dysenteriae Shiga. 



1 Work conducted under a grant of the International Health Board of the 

 Rockefeller Foundation. 



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