526 Bacilli Resembling the Typhoid Bacillus 

 BACILLUS DYSENTERIC (SHIGA). 



General Characteristics. A motile, flagellated, non-sporogenous, 

 non-liquefying, aerobic and optionally anaerobic, non-chromogenic, 

 non-aerogenic, pathogenic bacillus of the intestine, staining by ordi- 

 nary methods, but not by Gram's method. 



After considerable investigation of the epidemic dysentery 

 prevalent in Japan, Shiga * has come to the conclusion that 

 a bacillus which he calls Bacillus dysenteriae is its specific 

 cause. 



It is not improbable that the bacillus of Shiga is identical 

 with Bacterium coli, variety dysenteric, of Celli, Fioca, and 

 Scala,f a view that has been further confirmed by Flexner.J 

 It may also be identical with an organism described in 1888 

 by Chantemesse and Widal. 



Morphology. The organism is a short rod, very similar 

 to the typhoid and colon bacilli. It is feebly motile. 



Staining. When stained with methylene-blue the ends 

 color more deeply than the middle; and organisms from 

 old cultures show numerous involution forms and irregu- 

 larities. It stains with ordinary solutions, but not by 

 Gram's method. It has no spores, but has flagella (peri- 

 tricha). 



Cultivation. Colonies. The colonies upon gelatin 

 plates are small and dewdrop-like in appearance. Upon 

 microscopic examination they are seen to be regular and 

 of spheric form. By transmitted light they appear granular 

 and of a yellowish color. They do not spread out in a thin 

 pellicle like those of the colon bacillus, and there are no essen- 

 tial differences between superficial and deep colonies. 



Gelatin Punctures. The growth in the puncture culture 

 consists of crowded, rounded colonies along the puncture. 

 A grayish-white growth forms upon the surface. There is 

 no liquefaction of the gelatin. 



Agar-agar. Upon the surface of agar-agar cultures 

 kept in the incubating oven, large, solitary colonies are evi- 

 dent at the end of twenty-four hours. They are bluish- 

 white in color and rounded in form. The surface appears 

 moist. In the course of forty-eight hours a transparent 



* "Centralbl. f. Bakt. u. Parasitenk.," 1898, xxiv, Nos. 22-24. 

 f'Hygien. Institut. Rom. Univ.," 1895, and "Centralbl. f. Bakt. 

 'i. Parasitenk.," 1899. 



J "Univ. of Penna. Med. Bulletin," Aug., 1901. 

 See " Deutsche med. Wochenschrift," 1903, No. 12. 



