254 VETERINARY BACTERIOLOGY 



ods of animal inoculation, agglutination, precipitation, absorption 

 of complement, and by the use of mallein. 



Examination of Pits and Tissues. The discovery of a gram- 

 negative bacillus (in the pus or in tissues) having the general 

 characters of the glanders bacillus is presumptive evidence of its 

 presence, as there are few organisms with which it might be con- 

 fused. Inasmuch as the organism decolorizes easily and is gram- 

 negative it is difficult to demonstrate satisfactorily in tissues. 

 The method of Kiihne is recommended as giving good results. 

 Carbol-methylene-blue (methylene-blue, 1.5 gm.; alcohol, 10 c.c., 

 and 5 per cent, aqueous phenol or carbolic acid, 100 c.c.) is used to 

 stain the sections one-half hour; they are then washed in water, 

 then in very dilute hydrochloric acid (10 drops to 500 c.c. of water), 

 and quickly transferred to a solution of lithium carbonate (8 drops 

 of a saturated solution to 10 c.c. of water), then to distilled water, 

 dehydrated in absolute alcohol containing a little methylene-blue, 

 then cleared in anilin oil. The bacteria should show plainly. 



Diagnosis by Animal Inoculation. A male guinea-pig is in- 

 oculated intraperitoneally with a small amount of the suspected 

 material. This should be secured as free as possible from other 

 organisms to obviate the possibility of the animal dying pre- 

 maturely of peritonitis or septicemia. In from two to four days 

 the testes become enlarged and tender, the skin above them is 

 reddened and shiny. The animal, in case of a positive reaction, 

 should be killed and the contents of the testes examined micro- 

 scopically to determine the presence of a gram-negative charac- 

 teristic bacillus. Other organisms may give the orchitic reaction, 

 but they are gram-positive, with the exception of Bacillus pyo- 

 cyaneus. A culture should always be made from the pus in the 

 scrotum to make diagnosis certain. This reaction is sometimes 

 known as Strauss' biologic test. 



Agglutination Test for Glanders. The serum of a normal horse 

 will frequently agglutinate the B. mallei when in dilutions of 1 : 100, 

 1 : 500, rarely more. The serum from infected animals will in 

 general give a reaction in dilutions of 1 : 500, and usually much 

 higher. The organisms used in the agglutination test may be 

 either living or dead. The latter are commonly used, as it docs 

 away largely with danger of infection to man. The bacterial 



