162 VETERINARY STATE BOARD 



Name the channels through which the bacillus of tuberculosis may 

 enter the animal's body. 

 Alimentary tract, respiratory tract, genito-urinary tract, 

 abraded skin and mucous membranes. 



What is an acid-fast organism? Name the organisms belonging to 

 this group. 

 An acid-fast organism is one that is not decolorized by dilute 

 acids after being stained with the usual aniline dyes. 



B. tuberculosis, smegma bacillus, leprosy bacillus and the bacillus 

 of bacterial dysentery of cattle (Johne's bacillus) belong to this 

 group. 



Describe the bacillus of (a) tetanus, (b) anthrax, (c) tuberculosis. 



(a) A slender rod, from 4 to 5/i long and generally shows a 

 spore at one end which, being larger than the bacillus, gives it the 

 appearance of a pin or drtun-stick. It is anaerobic, stains readily 

 with aniline dyes and produces the most poisonous toxin of any 

 known bacteria. 



(b) A non-motile, rod-shaped organism, 5 to 20;li long ; a uniform 

 width of 1/i; square cut ends; grows in long filaments composed 

 of a large number of the organisms joined end to end. It forms verj'- 

 resistant spores and grows best under aerobic conditions. 



(c) Straight or slightly curved rods, 1.5 to 3.5/i long and 

 5/^/i wide, occurring singly or in bunches ; does not produce spores, 

 is acid-fast and difficult to cultivate on culture media until adapted 

 to such conditions. 



Describe the fungus of actinomycosis. 



This fungus belongs to the type of higher bacteria, known as 

 cladothrix or streptothrix. It is club-shaped and occurs as minute, 

 yeUow granules in the lesions; varies from 1 to 10/x long; can be 

 cultivated on artificial media and stains feebly with the aniline dyes. 

 In some varieties, the clubs show long, thread-like filaments attached 

 to them. 



Define (a) mallein, (b) tuberculin, 



(a) A liquid extract from cultures of the glanders bacillus used 

 as a diagnostic agent for glanders. It is prepared by growing 

 glanders bacilli in a flask of glycerinated bouillon for 6 or 8 weeks ; 

 the growth is filtered off and the filtrate is concentrated by boiling; 

 a small amount of a preservative, such as phenol, is added. 



(b) Tuberculin is a glycerine extract obtained from cultures of 

 the tubercle bacillus and is used as a diagnostic agent for tuber- 

 culosis. It is prepared similar to mallein, above described. 



