CHAPTER XXIII 



BACTERIACE^: BACILLUS MALLEI AND MISCELLA- 

 NEOUS BACILLI 



Bacillus (Bacterium) Mallei. — ^Loffler and Schiitz in 1882 

 obtained pure cultures of this organism from glandered horses 

 and produced glanders by the injection of these pure cultures. 



The bacillus is 0.3 to 0.5^ wide and 2 to S/i long, usually 

 straight with rounded ends, but sometimes irregular in shape. 

 Filamentous and branched forms have been observed in cultures. 



Pig. 139. — Bacillus mallei from an agar culture. X iioo. {After Park and 



'Williams.) 



It is not motile. Spores have not been observed. B. mallei is 

 stained with moderate difficulty and often stains unevenly like 

 the tubercle and diphtheria bacilli. After being stained, the 

 bacterium is easily decolorized in weak acid or alcohol; it is also 

 Gram-negative. Cultures develop on ordinary media, better on 

 glycerinated media, at temperatures ranging from 22° to 42° C, 

 best at 37° C. On potato at 37° C. a viscid yellowish-brown 



354 



