478 APPLICATION OF METHODS OF BACTERIOLOGY 



Diagnosis of the Disease by Agglutination and Complement- 

 fixation. The quickest and surest method of recognizing the 

 disease is by the specific agglutinating effect of the serum of 

 the diseased animal upon the organism of the disease. Many 

 different plans have been recommended. That of Moore, of 

 Cornell University, is one of the most trustworthy. He 

 recommends a test emulsion made by suspending a glycerin- 

 agar culture of glanders bacilli in physiological salt solution. 

 This is then exposed to 60 C. for two hours, whereby the 

 bacteria are killed, and is finally preserved by the addition 

 of 0.5 per cent, carbolic acid. To this suspension the serum 

 of the suspected animal is added in varying proportions 

 until a distinct clumping and sedimentation of the bacteria 

 is observed. Whenever done in a small test-tube of about 

 0.5 cm. diameter this reaction manifests itself as a gradual 

 clarification of the milky fluid and the accumulation of a mass 

 on the bottom of the tube. Normal horse serum in a dilution 

 of 1 to 300 to 1 to 200 causes the agglutination, while that 

 from glanders animals does the same in from 1 to 3200 to 

 1 to 500 dilution. 



The "complement-fixation" reaction may also be applied 

 both for the recognition of the condition i. e., for detecting 

 the specific antibodies in the tissues or fluids, as well as for 

 the identification of the specific exciter of the condition 

 i. e., the antigen. (See that reaction.) 



Mallein. The sterile filtered products of growth of the 

 glanders bacillus in fluid media represent what is known as 

 mallein a solution of compounds that bear to glanders a 

 relation analogous to that which tuberculin bears to tuber- 

 culosis. It is used with considerable success as a diagnostic 

 aid in detecting the existence or absence of deep-seated 

 manifestations of the disease, the glanderous animal reacting 



