Bacillus Indicus, Koch. 



B. BDBBR INDICUS. 



Origin. — Isolated in India from the contents of the 

 stomach of a monkey. 



Form. — Small, narrow, very short rod with rounded ends. 

 Motility. — Actively motile. 

 Sporulation. — Not definitely observed. 

 Anilin dyes. — Stain readily. 

 Growth. — Is rapid. 



Oelatin plates. — Deep colonies are yellowish, with a wavy contour. 

 Surface colonies grayish yellow, finely granular, with fibrillated bor- 

 ders. Show movement of contents, rapidly liquefy and may show a 

 light pink color. 



jS*a6 culture. — Rapid liquefaction along line of inoculation. 

 Dense flocculent growth settles on the bottom, and is grayish or light 

 pink in color. A delicate scum forms on the surface and is colored 

 from a light pink to a brick red. 



Streak culture. - On agar, it forms a low, moist, spreading growth 

 which usually is faint pink in color. On potato, the growth is low, 

 not slimy as that of B. prodigiosus, and the_ color is more marked 

 than on other media. On hloodrserum, liquefaction results with, or 

 without pigment production. 



Oxygen requirements.— It grows best in the presence of 

 air, but is a facultative anaerobe. The pigment production 

 depends upon the presence of oxygen. 



Temperature. — The optimum is about 35°. The pig- 

 ment is absent in cultures that develop in the incubator. 

 Splendid pigment when growth occurs at 15°. 



Behavior to gelatin. — It liquefies very rapidly. 



Pigment production. — Varies greatly. The pigment 

 may be grayish to bright brick-red; lacks the violet tinge 

 ■of B. prodigiosus. Usually it is light pink, so that the 

 •ordinary cultures may be considered as attenuated. 



Pathogenesis.— It has a marked toxic action, and when 



injected in large amounts into the abdominal cavity, or 



into the veins of rabbits and guinea-pigs, it proves fatal. 



Rabbits develop marked diarrhea and die in from 3 to 20 



hours. On post-mortem the intestines show a severe infiam- 



matory condition of the mucous membrane; at times, 



•.ulcerations are present. 



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