52 STUDY AND IDENTIFICATION OF BACTERIA 



The djsease has a very slight mortality (2%), and the lesions are chiefly 

 of the spleen, which is large and diffluent. The organisms can best be 

 isolated from the spleen. 



M. melitensis is only about .3^ in diameter. The characteristics 

 are its very small size and the dew-drop minute colonies on agar, 

 which at incubator temperature only show themselves about the third 

 to the sixth day. It is nonmotile and Gram negative. In bouillon 

 there is a slight turbidity. 



The organism occurs in the peripheral circulation, it having been 

 cultivated from blood very successfully by Eyre. He takes blood at 

 the height of the fever, and in the afternoon. Formerly it was custom- 

 ary to isolate by splenic puncture. 



Infection is chiefly by means of the milk of goats. The organisms 

 are excreted in the urine of patients, and a diagnostic point is to make 

 plates from the urine. Such urine applied to abraded surfaces causes 

 infection. 



The serum of patients shows agglutinating power as early as the 

 fifth day of the disease, and this may persist for years after recovery. 

 A dilution of 1 130 or i : 50 is recommended. 



