36 



BACILLUS INDICUS. Koch. 



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. Readily stain. 



Growth. Is rapid. 



Gelatin Plates. Deep colonies are yellowish, with wavy contour. Sur- 

 face colonies grayish yellow, finely granular, with fibrillated borders. Show 

 movement of contents, rapidly liquefy and may show a light pink color. 



Stich Cultures. 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 

 brick red. 



Streak Cultures. On agar, forms a low, moist, spreading growth, which 

 usually is faint pink in color. On potatoes, the growth is low, not slimy as M. 

 prodigiosus,and the color is more marked than on other media. On blood 

 serum, liquefaction results with or without pigment production. 



Oxygen requirements. Grows best in the pres- 

 ence of air, but is a facultative anaerobe. Pigment pro- 

 duction depends upon the presence of oxygen. 



Temperature. The optimum is about 35 C. Pig- 

 ment absent in cultures that develop in the incubator. 



Behavior to Gelatin. Liquefies very rapidly. 



Pigment production. Varies greatly. May be 

 grayish to bright brick red. Usually is light pink, so 

 that present cultures may be considered to be attenuated. 



Pathogenesis. Has marked toxic action, and when 

 injected in large amounts into the abdominal cavity, or 

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

 Rabbits develop marked diarrhoea and die in from 3 to 20 

 hours. On post-mortem the intestines show a severe 

 inflammatory condition of the mucous membrane and at 

 times ulcerations. 



