CHAPTER XLII 



ASIATIC CHOLERA AND THE CHOLEEA ORGANISM 

 (Spirillum choleroz asiaticce, Comma Bacillus) 



THE organism, of Asiatic cholera was unknown until 1883. In 

 this year, Koch/ at the head of a commission established by the 

 German government to study the disease in Egypt and India, dis- 

 covered the " comma bacillus" in the defecations of patients, and 

 satisfactorily determined its etiological significance. 



Koch's investigations were carried out on a large number of 

 cases and many investigations have since then corroborated his 

 results. 



Apart from the evidence of the constant association of the cholera 

 spirillum with the disease, the etiological relationship has been 

 clearly demonstrated by several accurately recorded accidental in- 

 fections occurring in bacteriological workers, and by the famous 

 experiment of Pettenkofer and Emmerich, who purposely drank 

 water containing cholera spirilla. Both observers became seriously 

 ill with typical clinical symptoms of cholera, and one of them nar- 

 rowly escaped death. 



Morphology and Staining. The vibrio or spirillum of cholera is 

 a small curved rod, varying from one to two micra in length. The 

 degree of curvature may vary from the slightly bent, comma-like 

 form to a more or less distinct spiral with one or two turns. The 

 spirals do not lie in the same plane, being arranged in corkscrew 

 fashion in three dimensions. The spirillum is actively motile and 

 owes its motility to a single polar flagellum, best demonstrated by 

 Van Ermengem's flagella stain. Spores are not found. In young 

 cultures the comma shapes predominate, in older growths the longer 

 forms are more numerous. Strains which have been cultivated 

 artificially for prolonged periods without passage through the animal 

 body have a tendency to lose the curve, assuming a more bacillus- 

 like appearance. The spirilla are stained with all the usual aqueous 

 anilin dyes. They are decolorized by Gram's method. In histological 



, Deut. med. Woch., 1883 and 1884. 



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