THE MALLEIN TEST 311 



is undisturbed the testicles later ulcerate, break through the skin, and 

 discharges a purulent fluid containing many bacilli. The animal 

 becomes emaciated and dies after ten to twelve days. The post- 

 mortem examination shows numerous glanders abscesses in the 

 testicles, the lymph nodes and in the internal organs, such as the liver, 

 spleen, kidneys, lungs, etc. When the test, however, is made for 

 diagnostic purposes the animal is not allowed to die, but is killed as 

 soon as the testicle shows a marked inflammatory swelling, which is 

 generally the case after two to three days and a postmortem examination 

 is made. In the case of glanders the examination of the testicles 

 shows small grayish-white transparent nodules, sometimes even 

 small abscesses, and smears from the nodules and abscesses show 

 the typical glanders bacilli. If the testicles are opened under aseptic 

 precautions the glanders nodule can also be used to obtain pure 

 cultures of the Bacillus mallei. It is always necessary to examine 

 smears from the swollen, inflamed testicles of the guinea-pig micro- 

 scopically and to stain with Loeffler's or with Kiihne's stains and by 

 Gram's method, because certain other bacteria also bring about an 

 orchitis (inflammation of the testicles) if inoculated intraperitoneally 

 into a male guinea-pig. These bacteria, however, are all Gram 

 positive. They are Nocard's bacillus of ulcerative lymphangitis of 

 the horse. Preisz's bacillus of pseudotuberculosis of the sheep, 

 Kutscher's bacillus found once in the nasal secretion of a horse, and 

 also sometimes the Bacillus pyocyaneus. Young cats may also be 

 used for subcutaneous inoculation with glanders-suspected material. 

 They develop first a local swelling and ulceration and later a general 

 glanders infection. 



The Mallein Test. Mallein 1 is a vaccine, prepared from killed, 

 virulent glanders bacilli. It is injected into a soliped suspected of 

 glanders, and if the disease is present a typical local and general 

 reaction occurs. Very little is known concerning the mode of action 

 of the Bacillus mallei, but there is good reason to believe that its 

 pathogenic properties depend, if not exclusively, at least largely, upon 

 resistant endotoxins. The latter are present in the mallein; they 

 represent the antigen (see chapter on Antibodies), which gives rise to 

 the formation of specific glanders antibodies. The local and general 

 reaction in malleus-infected horses, when injected with mallein, is 

 probably due to an interaction between the malleus antigen and the 

 malleus antibodies. 



Mallein is prepared according to various methods; that of Roux, 

 of the Paris Pasteur Institute, is as follows: The virulent cultures of 

 glanders bacilli are obtained by long-continued intravenous injections 

 of bacilli into rabbits. When the cultures have become so virulent 

 that they will kill rabbits in thirty hours they are grown in flasks 



The term mallein was formed on the analogy of the word tuberculin. The term was 

 first used by Helman, the original maker of the vaccine. German writers sometimes use 

 the term "Rotzlymphe," and French authors the word "morvin," for mallein. 



