ABSTRACTS 116 



sitive readings resulted in all tests with sera from cholera hogs with 

 2 exceptions. 



Complement fixation is coincident with chnical symptoms and 

 depends upon the virulence of the infecting material and the individual 

 resistance of the animal. 



Tests of two convalescent hogs indicate that complement binding 

 substances cease to exist in the blood of hogs when immunity against 

 hog cholera becomes fully established. 



Control antigens made from cultures of B. choleras-uis, B. Voldagsen 

 (Haendel), B. typhi-suis (Glaesser) fail to exhibit complement fixation 

 with cholera sera. 



Antigen prepared from pure cultures of Spirochaeta hyos possesses 

 no complement binding properties upon sera of hogs suffering from 

 septicemia, B. cholera-suis infection, Anthrax, Ghon-Sachs infection, 

 brine poisoning, or pneumonia from natural exposure. 



We believe that, by the observance of proper technique, the results 

 recorded herein can be dupHcated without difficulty and that the 

 method may be used to practical advantage as a reliable, accurate 

 means of laboratory diagnosis of hog cholera. Furthermore, the 

 results of these experiments support our former conclusions that Spiro- 

 chaeta hyos merits serious consideration as an organism possessing 

 specific pathogenic properties in relation to hog cholera. 



Antigenic Properties of Autolysed Bacteria. George H. Robinson. 



Meningococci were allowed to autolyse at different temperatures 

 for varying periods of time. The filtrates and residues were tested for 

 their complement fixing and complement absorbing properties. Only 

 after 24 hours in distilled water at 56° is the fixing power of the filtrate 

 greater than that of the residue. The fixing power of autolysed sus- 

 pensions decreases in proportion to the extent of autolysis indicating 

 a degradation of the protein. A small portion of the original antigenic 

 substance is obtained in a filtrate after autolysis. A fresh, washed, 

 bacterial suspension gives more satisfactory results as an antigen for 

 complement fixation tests than an autolysate. 



The Effect on Horses of Feed Heavily Inoculated with B. coli Isolated 

 from Oat Hay. Robert Graham and L. R. Himmblberger. 

 The occurrence of B. coli or colon-like organisms on grains hap 

 been demonstrated numerous times. Recently Rogers, Clark and 

 Evans^ pubHshed a report of their studies of colon bacteria on grains. 

 They isolated one hundred and sixty-six cultures, of which seventy- 

 five were obtained from corn, six from barley, thirty from wheat and 

 forty-one from oats. The grains used were secured from the grain 

 inspection laboratory and should therefore represent average samples 

 grown throughout the different sections of the United States. This 

 widespread occiu-rence of colon-like organisms on grains, together with 

 the fact that B. coli or colon like organisms appeared to be constantly 



^ Journal of Infectious Diseases, vol. 17, no. 1, 1915. 



