TOXINS 897 



(a) What are the symptoms of dysentery intoxication? 



(b) Observe the temperature at frequent intervals. Are there any 

 changes? 



(c) Does the animal which received the toxin by mouth show symp- 

 toms? How do you explain the result? 



(d) Autopsy the animals with particular attention to the gastro- 

 intestinal tract. Are there any evidences of a selective action of the 

 toxin? 



EXPERIMENT 12. STAPHYLOTOXIN 



Inject 2 c.c. of a twenty-four-hour bouillon culture of Staphylococcus aureus in 

 the ear vein of a rabbit. Take the temperature before and every twelve hours 

 after injection. Autopsy the animal seventy-two hours later under aseptic precau- 

 tions. 



(a) What lesions are found? 



(b) Where are these chiefly situated and why? 



(c) Culture the heart's blood on tubes of agar, also several of the 

 lesions. 



(d) After twenty-four hours' incubation examine your cultures. 



(e) What was death due to? 



(f) Define bacteremia. 



(g) Prepare and stain sections of the kidney, including a lesion. 

 What are the histologic changes? How do you explain the production 

 of these tissue changes? 



EXPERIMENT 13. STAPHYLOTOXIN 



1. Inoculate a flask of neutral bouillon with a virulent culture of Staphylococcus 

 aureus and grow for two weeks at 37 C. Filter through a Berkefeld filter. 



2. Prepare a 1 per cent, suspension of washed rabbit erythrocytes in normal salt 

 solution. 



3. Into a series of six test-tubes place 1 c.c. of the corpuscle suspension and in- 

 creasing amounts of Staphylococcus filtrate: 0.1 c.c., 0.2 c.c., 0.4 c.c. 0.8 c.c., 1 c.c., 

 and 2 c.c. Add normal salt solution to bring the total volume to 3 c.c. 



4. Prepare a control by placing 1 c.c. of corpuscle suspension in 2 c.c. salt solution. 



5. Incubate tubes for two hours at 37 C. and read results. 



6. This test will be referred to again in the technic for determining the antilysin 

 in blood-serum. 



(a) Has hemolysis occurred in any of the tubes? 



(b) To what constituent of the filtrate are these results due? 



(c) Does this experiment show the selective action of a toxin? 



(d) Do the results have any bearing upon the anemia and jaundice 

 of severe Staphylococcus infections? 



57 



