\-2J MXKTRKNTH HHPOHT. 



Immune colon serum. Iiii>litst dilution. 1-300. 

 Immune paratyphoid A serum, liiffhest dilution. 1-10. 

 Immune paratyphoid B serum, highest dilution, 1-50. 

 Immune enteritidis serum, highest dilution. 1-50. 



Tlie immune serum of tlie eheese poisoning haeiihis agglutinated the 

 above organisms in the following dilutions: 



B. Colon 1-100 



B. Paratyphoid A 1-10 



B. Paratyphoid B '. 1-10 



B. Enteritidis I-IO 



Cheese poisoning haeillus 1-2000 



The bacillus was found to be pathogenic not only to mice, rats, and 

 guinea pigs, but also to rabbits, cats and dogs. In eats, inter peritoneal 

 injections of the organism causes retching, vomiting, and purging, and 

 also a high fever, ^^'llen injected with ))eritoneal exudates from ani- 

 mals, as guinea pigs, killed by the bacillus, the cats die within 12 to 24 

 hours. P'eeding of the poisonous cheese or of food, as milk or meat, 

 saturated with a culture of the organism, i)roduces no effects. 



The organism does not form tyrotoxicon. It does elaborate a soluble 

 thermo-stabile poison in sugar media, preferably a 0.5% lactose broth, 

 neutral to ])henolphthalein ; 0.25ce of the sterile filtrate of such a culture 

 kills a 100 gram guinea ])ig witliin "five hours. When injected into 

 cats the filtrate causes tlie same symptoms as the virulent organism. 

 Rabbits give a marked febrile reaction. 



.Milk cultures of the organism, when incubated at 37" C for thirty 

 days, will become curdled. If now the whey from such a culture be 

 separated from the curd aiul sterilized by filtration through a Berkefeld 

 candle, and then extracted with alkaline ether, it will be found that this 

 extract may possess some toxic action on guinea pigs. If guinea pigs 

 be injected at intervals of five to seven days with increasing doses of 

 this alkaline ether extract they will show a marked protection against, 

 and at times complete immunity to. virulent cultures of tlie organism. 



Ciuinea pigs can also be immunized to the virulent organism by vaccine 

 and immune serum injections. Immunity to the soluble poison is more 

 difficult to obtain. 



