THE COLON BACILLUS 379 



nised with the toxin, or with dead and then with living 

 cultures, possesses marked antitoxic properties, and the 

 use of this antitoxic serum has been successful in cases 

 of acute bacillary dysentery. Shiga obtained a reduction 

 in mortality from 22 to 7 per cent, by the use of serum 

 in a severe epidemic, and striking results were obtained 

 by Buffer and Willmore 1 in Egypt and by Bahr in Fiji. 

 It is necessary, however, to employ a serum prepared with 

 the particular strain of the disease. 



When the disease has become chronic the use of a 

 vaccine, consisting of a culture sterilised by heat, is some- 

 times beneficial. Castellani also suggests the use of a 

 vaccine for prophylactic purposes. 



Para-dysentery bacilli. In the dysenteries of Ceylon, 

 Castellani 2 has sometimes isolated dysentery bacilli nearly 

 related to the Shiga-Kruse type, but showing differences 

 from it in agglutination, persistence of acid reaction in 

 litmus milk, and virulence ; these he has termed " para- 

 dysentery " bacilli. 



Asylums dysentery and summer diarrhoea of infants. 

 Both in America and in England some cases of summer 

 diarrhoea of infants are found to be associated with the 

 B. dysenteries (see above, p. 374). The asylums or insti- 

 tutional dysentery, or ulcerative colitis, is also due to 

 this organism, and the blood of patients gives the agglu- 

 tination reaction. 3 In both instances the B. dysenteries 

 present is of the Shiga-Kruse type. 



Bacillus coli 



The Bacillus coli, or colon bacillus (B. coli communis), 

 is an organism of considerable importance, both in con- 



1 Brit. Med. Journ., 1909, vol. ii, p. 862, and 1910, vol. ii, p. 1519. 



2 Journ. of Hygiene, vol. iv, 1904, p. 495. 



3 Hewlett, Trans. Path, Soc, Lond,, vol. Iv, 1904, p. 51. 



