STUDIES ON FOWL CHOLERA 



V. THE TOXINS OF BACILLUS AVISEPTICUS^ 

 PHILIP HADLEY 



Received for publication June 15, 1917 



In presenting the results of his very suggestive studies on the 

 agglutination of bacteria in vivo, Dr. Bull (1916) makes the 

 following statement : 



From table 1 it is seen that bouillon cultures of Bacillus avisepticus 

 are highly toxic for rabbits, 0.5 cc. of culture per kilo causing acute death. 

 The intoxication is largely due to a toxin, since 1 cc. per kilo of body 

 weight of a bacteria-free filtrate from a twenty-four hour culture causes 

 acute death. 



and again : 



These results especially emphasize the significance of agglutinins and 

 opsonins in the mechanism of natural resistance to infection, since 

 Bacillus avisepticus produces a powerful toxin and is still incapable of 

 causing a septicemia of any consequence in the presence of these anti- 

 bodies. 



In view of the difficulty of reconciling these conclusions with 

 studies conducted by other investigators upon Bacillus avisepti- 

 cus, as well as with observations made by the present writer 

 (Hadley 1912, 1914a, 1914b, 1917) in studies on infection and 

 resistance in fowl cholera, it seems desirable to bring into relief 

 the somewhat extraordinary nature of the statements made by 

 Dr. Bull with reference to toxin-production by virulent cultures 

 of the fowl cholera bacteria. This is perhaps especially desirable 

 at this time in view of the many current misconceptions regarding 



1 Contribution 233 from the Agricultural Experiment Station of the Rhode 

 Island State College. 



277 



