CHAPTER II 



MALIGNANT EDEMA 



Bacillus GEdematis Maligni (Koch) 



Synonym. — Vibrion septique. 



General Characteristics. — A motile, flagellated, sporogenous, anaerobic, 

 liquefying, aerogenic, non-chromogenic, pathogenic bacUlus of the soil, readily 

 stained by the ordinary methods, but not by Gram's method. 



This organism was originally found by Pasteur* in putrescent 

 animal infusions and called by him (1875) Vibrion septique. It was 

 later more carefully studied and described by Koch, f 



It is supposed that this bacillus was among the organisms whose 

 introduction into wounds in the days of pre-antiseptic surgery, 

 commonly occasioned the then prevalent "Hospital gangrene." 



Distribution. — The organism is widely distributed in nature, 

 being commonly present in garden earth. It is also found in dusts, 

 in waste water from houses, and sometimes in the intestinal content 

 of animals. 



Morphology.- — ^The bacillus of malignant edema is a large rod- 

 shaped organism with rounded ends, measuring 2 to 10 /x by 0.8 

 to i.o jtt. It is usually motile, and possesses many flagella. It pro- 

 duces oval endospores centrally situated and giving a barrel shape 

 to the parent bacillus. 



Staining.— The bacillus stains well with ordinary cold aqueous 

 solutions of the anilin dyes, but not by Gram's method as a rule. 



Cultivation.— The organism is a strict anaerobe, but under con- 

 ditions by which provision is made for the removal of oxygen, grows 

 well both at the room temperature and at that of the incubator. 

 It is not difficult to secure in pure culture, being most easily obtained 

 from the edematous tissues of guinea-pigs and rabbits inoculated 

 with garden earth. 



Colonies. — The colonies which develop upon the surface of 

 gelatin kept under anaerobic conditions appear to the naked eye 

 as small shining bodies with Hquid, grayish-white contents. Under 

 the microscope they appear filled with a tangled mass of long fila- 

 ments which under a high power exhibit active movement. The 

 edges of the colony have a fringed appearance, much like the colonies 

 of the hay or potato bacillus. 



Gelatin. — ^In gelatin tube cultures the characteristic growth 

 cannot be observed unless the tube be placed under anaerobic 



* "Bull. Acad. Med.," 1877 and 1881. 



f'Mittheilungen aus dem kaiserl. Gesundheitsamte," i, 53. 



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