INFECTIOUS ABORTION IN SWINE 419 



SOWS and the immune serum mentioned, the complement was 

 completely fixed with 0.02 cc. of serum. We were thus convinced 

 that this organism was identical with the germ that produces 

 abortion in the cow, the only difference being that it grew readily 

 in the air after the first generation, while the cultures we have 

 derived from the cow usually do not grow in the air until a ter 

 being cultured for several generations by the Nowak method. 

 An exception to this rule, was discovered by Dr. Frank M. Sur- 

 face,2 who accidently inoculated a cow with a culture of the 

 Bang bacillus which had repeatedly been transplanted for some 

 two years from agar to agar, or from agar to plain peptone broth, 

 and then back to agar. He had obtained this particular strain 

 while in Denmark. The cow injected, aborted and Surface 

 isolated the organism, the first generation of which developed in 

 the air. He was able to determine definitely, by using this or- 

 ganism as an antigen in the complement fixation test with an 

 immune serum, that it was the Bang bacillus. Surface states 

 that the growth obtained in a Novy jar (Nowak method) was 

 in no respect better than that obtained in the free air. 



We cannot state whether the organism isolated from the abort- 

 ing sow would have grown directly from the tissues, as we cultured 

 none of the material in that way for any length of time. Upon 

 re-culturing the original material, which had been kept in the 

 ice box, we found that the contaminating bacteria had become 

 so numerous as to make streak dilutions impossible. 



INOCULATION EXPERIMENTS WITH THE ORGANISM OBTAINED 

 FROM THE ABORTING SOW 



To test this organism further, a streak culture on an agar 

 slant was washed with 5 cc. of physiological salt solution and 

 2 cc. of this material was diluted in 3 cc. of normal salt solu- 

 tion and injected intravenously into a pregnant sow, no. 1, on 

 February 25, 1916. On March 13, seventeen days after the 

 inoculation, this sow aborted five fetuses. The only symptom 



2 Surface, F. M., A Note on the Maintenance of Virulence by Bacillus Abor- 

 tus Bang, Journal of Infectious Diseases, 1913, 12, p. 359. 



