CHAPTER XXXI 



SPIEAL BACTBEIA— ASIATIC CHOLEEA— THE GENUS 

 VIBRIO 



The organisms belonging to tlie genus Vibrio have been 

 isolated repeatedly from, water, sewage and the tilimentary 

 canal of man and animals. A few species are known which 

 are associated with disease. One, the Vibrio metchnikovii 

 produces a septicemia of fowls in Europe and the Vibrio 

 cholerce, the disease Asiatic cholera in man. The latter dis- 

 ease is the only one which has invaded the United States 

 and it alone will be discussed. 



VlBEIO CHOLERyE 



Synonyms. — Spirillum comma, Spirillum, cholera asiaticm, 

 Microspira comma. 



This organism is the specific cause of the disease Asiatic 

 cholera in man. It was first discovered by Robert Koch in 

 1883 who found it in the rice-water stools of patients having 

 the disease. Apparently this disease is constantly present 

 in certain parts of Asia, particularly in China. Prom this 

 region it has spread in epidemics over Europe and United 

 States during the past century. 



Morphology. — The cholera vibrio is a short, slightly 

 curved rod frequently known as the ' ' comma bacillus. ' ' It 

 is motile by means of a single polar flagellum. Elongated 

 cells and involution forms are commonly produced in cul- 

 ture media. No spores and no capsules can be demon- 

 strated. The organism is Gram-negative and stains readily 

 with the usual aniline dyes. Isolation of the organism from 

 the tissues of an Asiatic cholera patient is usually accom- 



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