376 A MANUAL OF BACTERIOLOGY 



prepared with para-typhoid bacilli in the same manner as 

 for typhoid fever and Castellani has made use of a mixed 

 typhoid-para-typhoid vaccine. 



Bacillus dysenteriae l 



In one type of dysentery, the so-called epidemic or 

 bacillary form (see " Dysentery," Chap. XX), a bacillus 

 B. dysenteries, is the causative agent. The B. dysenteries 

 includes a group of closely allied organisms. 



The dysentery bacillus was first isolated in 1897 by 

 Shiga in Japan. Somewhat later Kruse isolated an almost 

 identical bacillus in Germany, and this type is known as 

 the Shiga-Kruse type. Later, Flexner and Strong isolated 

 another type of the dysentery bacillus, and during the 

 last few years similar organisms, but differing from the 

 Shiga-Kruse and Flexner types in some of their fermenta- 

 tion and other reactions, have been isolated ; these are 

 sometimes termed " pseudo-dysentery " bacilli. 



The Shiga-Kruse and other types of dysentery bacilli 

 have been isolated by Flexner and Strong in the Philip- 

 pines, Park, Duval, Bassett, Martini, Hiss, Russell and 

 others in the United States, Castellani in Ceylon, Rogers 

 and others in India, RufTer and Willmore in Egypt (El 

 Tor), and Eyre, McWeeney and others in the British Isles. 



Morphology. The B. dysenterice are small slender bacilli 

 much resembling the colon bacillus. They are non-motile, 

 but Brownian movement is often active, 2 Gram-negative, 

 and non-sporing, and are readily destroyed by heat (58 

 60 C.) and antiseptics. 



Cultural characters. The dysentery bacilli are aerobic 

 and facultatively anaerobic. On agar a thinnish creamy 



1 See an excellent summary by P. H. Bahr, Dysentery in Fiji 

 (Witherby & Co., London, 1912). 



2 Flagclla have been described by some observers, but cannot usually 

 be demonstrated. 



