356 ' SPECIFIC MICRO-ORGANISMS 



brotli and injected into the peritoneal cavity of a male guinea-pig 

 (method of Straus). If B. mallei is present a general inflamma- 

 tion of the peritoneum develops and after three or four days the 

 testicles of the animal become swollen, inflamed and later suppu- 

 rate. They may burst through the scrotum. Cultures should 

 be made from this pus on plates of glycerin agar and the colonies ' 

 transplanted to potato at 37° C. Very few other organisms 

 give rise to a similar pathological picture in the guinea-pig.' At 

 the same time the mallein test is carried out by injecting 0.2 cc. 

 of the concentrated mallein diluted with 0.25 per cent solution 

 of carbolic acid into the suspected horse. The presence of gland- 

 ers is indicated by a rise in temperature of 2" to 5° F., signs of 

 general intoxication, and especially by swelling and inflammation 

 at the site of injection. For the agglutination test the serum 

 is diluted to 1:500 to 1:3000. Positive results with lower dilu- 

 tions may apparently be given by normal horses. The comple- 

 ment-fixation test follows the principles of Wassermann test for 

 syphilis, a culture of B. mallei being employed as antigen.' At- 

 terilpts at immunization have not been practically successful. 



Bacillus (Bacterium) Abortus.' — Bang and Stribolt, working 

 in Denmark in 1897, isolated this organism from the uterus of a 

 cow suffering from the disease known as contagious abortion, 

 and reproduced the disease by inoculating healthy cows with 

 these cultures, The same organism was isolated by MacNeal 

 and Kerr^ in 1910 from aborting cows in the United States. The 

 organism is of interest because of its behavior toward oxygen when 

 first isolated. It fails to grow in the air or in hydrogen, but grows in 

 a partial pressure of oxygen somewhat below that of the atmos- 

 phere. The bacillus is pathogenic for a number of different 

 mammals, and in guinea-pigs it causes granulomatous lesions 

 resembling somewhat those of tuberculosis.^ The organism ■ 



1 Mohler and Fichorn: Twenty-seventh Annual Rep. Bur. Anim. Industry, U. S. 

 Dept. Agr., 1910; reprinted as Circular 191 (1912). 



^ MacNeal and Kerr, Tourn. Infectious Diseases, 1910, 7, p. 469. 



'Smith and Fabyan: Cenlr. j. Bakt., I, Abt. Orig., 1912, Bd. LXI, S. 549-555. 

 Fabyan, Jowrn. Med. Rsch., 1912, Vol. XXV, p. 441-488. 



