DIFFERENTIAL DIAGNOSIS 



l8l 



pend upon the bacteriological 

 euces between the two species 

 the comparison appended. 



Bacillus of hog cholera. 



1. Rod-shaped organism with 

 ends rounded, 1.2 to 2.011 in length, 

 0.5 to o.S..' in width. The size varies 

 according to the stage of growth 

 and division and the culture media. 



2. From cultures it stains en- 

 tirely. In tissues it usually stains 

 around the periphery leaving a 

 light centre. 



3. Actively motile in liquids. 



4. From 3 to 9 flagella are de- 

 monstrable. 



5. Vigorous growth in alkaline 

 nutrient liquids. Less vigorous if 

 liquids are acid in reaction. 



6. Moderate growth on potato. 

 (Varies according to reaction. ) 



7. Distinct growth on gelatin. 



S Saponifies milk in from 3 to 4 

 weeks. 



9. Ferments dextrose with the 

 formation of acids and gas. 



10. Does not ferment lactose. 

 Bouillon containing it becomes 

 strongly alkaline. Xo gas. 



11. Does not ferment saccha- 

 rose Bouillon containing it be- 

 comes strongly alkaline. No gas. 



12. Destroyed by moist heat at 

 58° C. in 15 minutes. 



13. Dies in water in from 2 to 4 

 months. 



14. It dies in the soil in from 2 

 to 3 months. 



15. Rabbits injected subcutane- 

 ously with o. i c.c. of a bouillon 

 culture of a virulent bacillus will 

 die in from 5 to 7 days. Enlarged 

 spleen, necrotic foci in liver. 



findings. The essential difFer- 

 of bacteria are brought out in 



Bacterium of szviiic plague. 



1. Enlongated oval organism 

 o.S to i.5/( in length, 0.6 to o S« in 

 thickness. The size varies accord- 

 ing to the stage of growth and 

 division and the culture media. 



2. From old cultures it usually 

 stains entirely. When in pro- 

 cess of division as found in the 

 organs of freshly dead rabbits the 

 extremities stain leaving an un- 

 stained central band, "polar stain." 



3. Not motile in liquids. 



4. No flagella have been found. 



5. Growth moderate or feeble 

 in alkaline nutrient liquids. No 

 growth if liquids are acid. 



6. No growth on potato. 



7. FeeV)le or no growth on gela- 

 tin. 



8. Produces no apparent change 

 in milk. 



9. Ferments'dextrose with the 

 formation of acids but no gas. 



10. Does not ferment lactose. 

 No. gas. 



11. Ferments saccharose with 

 the formation of acids. No. gas. 



12. Destro}'ed by moist heat at 

 58° C. in 7 minutes. 



13. Dies in water in from 10 to 

 15 days. 



14. It dies in the soil in from 4 

 to 6 days. 



15. Rabbits injected subcutane- 

 ously with o.oi c.c. of a bouillon 

 culture of a virulent bacillus will 

 die in from 16 to 20 hours. Septi- 

 ctemia. 



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