296 BACILLI OF THE TYPHOID GROUP 



Rettger and Harvey inoculated a number of chicks with three stems 

 of their bacillus obtained from three different epidemics. Most 

 inoculations were successful and led to a typical fatal attack of 

 white diarrhea. From the dead chicks the organism could again 

 be obtained in pure cultures. A few feeding experiments also gave 

 positive results. 



Morse, who studied white diarrhea in chicks before the publication 

 of Rettger and Harvey's work, came to the conclusion that the affection 

 was due to a protozoan organism, i. e., Coccidium tenellum. 



QUESTIONS. 



1. What bacteria belong to the typhoid-colon-hog cholera group of bacilli? 



2. Name some of their common properties. 



3. In what respect do they differ from each other? 



4. What other names have been given to the disease hog cholera? 



5. What is the hog-cholera bacillus or Bacillus suipestifer? 

 , 6. Discuss the geographical occurrence of hog cholera. 



7. Describe in general terms the pathologic lesions of the disease. 



8. Describe the lymphatic glands in the disease; also the changes found in 

 the gastro-intestinal tract. 



, 9. Describe the appearance of the kidneys. 



10. Describe the morphology and the staining properties of the Bacillus 

 cholerae suis. 



11. At what temperature does this organism grow? 



12. What sugars are fermented by this bacillus? 



13. Describe its growth on gelatin plates and in gelatin stick culture. 



14. How does it act when growing in milk? How in bouillon? 



15. Does it form indol? 



16. Give the differential features of Bacillus suipestifer and Bacillus (bipolaris) 

 suisepticus. 



17. Discuss the resistance of Bacillus cholerae suis. 



18. Give a definition of the term filterable, invisible, ultramicroscopic virus. 



19. Describe the experiences and experiments which have led to the recog- 

 nition of the fact that hog cholera is not due to the Bacillus cholerae suis. 



20. Describe the method of hyperimmunizing hogs against hog cholera to 

 obtain an immune or antiserum of high value. 



21. What is an immune hog? 



22. How is hog-cholera blood tested as to its virulency? 



23. How soon is the virulent blood neutralized in the body of an immune hog? 



24. Describe methods of obtaining the immune serum from the hyperimmunized 

 hog. 



25. Describe the method of testing the immunizing or protecting power of 

 the immune serum. 



26. Describe the method of procuring passive immunity in non-immunes. 



27. Describe the simultaneous method of producing a more lasting active 

 immunity. 



28. In what dilution does the blood serum from a healthy hog agglutinate the 

 hog-cholera bacillus? 



' 29. What effect has the intraperitoneal injection of vaccines prepared from 

 the Bacillus cholerae suis upon the agglutinating power of hog's blood toward 

 this organism? 



30. How does the blood serum of hogs hyperimmunized against hog cholera 

 behave toward the Bacillus cholerae suis? 



31. What human and what animal diseases are caused by the Bacillus typhosus? 



32. How is typhoid fever spread? 



33. How can typhoid bacilli be detected in milk or water? 



34. Describe the preparation of the Drigalski-Conradi medium. 

 "35. How is it used? How do typhoid cultures look on it? 



36. Describe the morphology of the typhoid bacillus. 



