450 



BACILLUS OF MALIGNANT CEDEMA 



wounds. Weinberg places it along with the latter organism as 

 a cause of " classical gas gangrene," though it is much less 

 common, and usually occurs in association with other organisms. 

 He, moreover, states that cases of pure infection are rare, and 

 that in these emphysema is not a striking feature, gas occurring 

 only in the deeper tissues in small bubbles, and sometimes only 

 recognisable at operation. These features accordingly corre- 

 spond with those in the case referred to. 



Microscopical Characters. — The vibrion septique, or bacillus 

 of 'malignant cedema, is a comparatively large organism, being 



slightly less than 1 /* in 

 thickness, that is, thinner 

 than the anthrax bacillus. 

 It usually occurs in the 

 form of single rods 3 to 

 10 /a in length, but both 

 in the tissues and in cul- 

 tures in fluids it frequently 

 grows out into long fila- 

 ments, which may be 

 uniform throughout or 

 segmented at irregular 

 intervals. In cultures on 

 solid media it chiefly occurs 

 in the form of shorter rods 

 with somewhat rounded 

 ends. The rods are motile, 

 possessing several laterally 

 placed flagella. Motility is 

 usually well marked in the 

 serous exudate of the 

 lesions, but in cultures only a few bacilli may show active 

 movement. Under suitable conditions they form spores, which 

 have an oval shape, their thickness somewhat exceeding that 

 of the bacillus; they are central or subterminal in position. 

 In acute spreading lesions the bacilli are usually free from 

 spores, but at a later period they may be found (Fig. 129). 

 The bacillus can be readily stained by any of the basic aniline 

 stains. There is difference of statement as to the reaction 

 to Gram's stain. Earlier writers agreed that the organism 

 was Gram-negative, but in most recent papers it is described 

 as Gram-positive, though it is admitted that in older cultures 

 Gram-negative forms appear. 



Characters of Cultures. — This organism is a strict anaerobe; 



Fig. 130. — Bacillus of malignant oxlema, 

 showing spores. From a culture in 

 glucose agar, incubated for three days 

 at 37° C. 



Stained with weak carbol-fuchsin. x 1000. 



