58 ELEMENTARY BACTERIOLOGY LABORATORY EXERCISES 
lesions. Apply the acid fast stain and examine for the presence of Mycobacterium 
tuberculosis. 
EXERCISE 88 
ANTHRAX 
From the culture of Bacillus anthracis furnished, make cultures on- (1) agar 
slope, (2) nutrient broth, (3) gelatin and (4) litmus milk. For comparative pur- 
poses, inoculate additional tubes of the same media with Bacillus cereus. Incu- 
bate all the cultures at 37° C. 
Note the cultural characteristics of these organisms on the different media. 
Make stained preparations by the Gram method from the agar slope and broth 
cultures. Note the morphology and staining characteristics of the organisms. In 
which media is spore formation more abundant? How do these organisms com- 
pare in morphological and cultural characteristics, and in motility? 
Observe the subcutaneous inoculation of a guinea pig with Bacillus anthra- 
cis. Note carefully the details of the inoculation as demonstrated. As a control, 
inoculate another guinea pig with an equal amount of Bacillus cereus. 
Immediately after death of the animal inoculated with the anthrax bacillus 
make a post-morten examination. Note the condition of the various internal or- 
gans. Make agar slope cultures from the spleen, liver and heart blood and incu- 
bate at 37° C. Make Gram stain preparations from the spleen, liver and heart 
blood. After incubation, examine the agar slope cultures made from organs of 
the anthrax infected guinea pig. Note whether the type of growth and mor- 
phology are typical of Bacillus anthracis. 
Note if any ill effects have been produced in the guinea pig inoculated with 
Bacillus cereus. 
