388 



AGRICULTUEAL AND INDUSTEIAL BACTEEIOLOGY 



Morphology The glanders bacillus is a short usually 



straight rod, sometimes somewhat curved, with rounded 

 ends. It occurs rarely in short chains, usually it is single. 

 In the stained mounts made from infected tissues the cells 

 occur frequently in pairs. Involution forms, enlarged and 

 clubbed cells, filamentous and branched forms are not 

 infrequently observed. In this respect it resembles the 

 organisms belonging to the genus Corynebacterium. The 

 rods usually vary from 0.5-ljiiby 1.5-5 m. They are non- 

 motile, do not produce spores or capsules. They stain well 

 with aniline dyes, are not acid fast and are Gram-negative. 



Cultural Characters. — The organism is ordinarily found 

 in the nasal discharges in glanders and in the pus from 

 farcy ulcers in the horse. In order to secure the organism 

 in pure culture, it is customary to inject intraperitoneally 

 into a male guinea pig. Within two to four days, the 

 organism may be isolated in pure culture from lymph glands 

 or from the testes. The orchitis developing is quite charac- 

 teristic. 



The organism grows readily upon the ordinary media, 

 particularly when they contain glycerin or blood serum. 

 Upon agar and glycerin agar the colonies are usually cir- 

 cular, glistening and whitish or yellowish. Growth upon 

 potato medium is among the most characteristic. "Within 

 two days at blood heat a yellow, honeylike, transparent 

 growth which finally turns brownish or amber in color is 

 developed, while the potato itself becomes a greenish-brown 

 color. 



Physiology. — The organism is aerobic and facultative 

 anaerobic, growing best at blood heat but fairly well at 

 lower temperatures. It is readily destroyed by heat. 



Pathogenesis. — The organism is primarily an invader 

 of the lymph glands of the horse. The first lesions are 

 usually in the nose, producing the disease type termed 

 glanders. When the subcutaneous lymph glands are 



