SIMILAR VIBRIOS 503 



Cultural characteristics. Cultures of the Finkler-Prior vibrio resemble those of 

 the cholera vibrio. The former liquefies gelatin more rapidly and does not form 

 a bubble of air on the surface of the liquefied portion ; it coagulates milk. 



Biological properties. The Finkler-Prior vibrio produces indol but only traces 

 of nitrites. The nitroso-indol reaction is positive but only slightly marked and 

 slowly produced (several days). 



The Vibrio of Deneke. 



This vibrio was isolated by Deneke from an old cheese. Morphologically, it is 

 similar to the cholera vibrio and in gelatin plate cultures the appearance of the 

 colonies of the two organisms may be identical. It liquefies gelatin rather more 

 quickly than the cholera vibrio but less rapidly than the Finkler-Prior vibrio. 



Guinea-pigs die as the result of intra-peritoneal inoculation of the vibrio (Hueppe, 

 Metchnikoff) : the organism is also pathogenic for pigeons (Kasanky, Metchnikoff). 

 In man, infection with the organism causes diarrhoea (Metchnikoff). 



Deneke's vibrio produces indol but very little nitrites. The cholera-red reaction 

 is inconstant and very poorly marked. 



Vihrio Metchnikowi. 



(Vibrion avicide.) 



The Metchnikoff vibrio was discovered in Odessa by Gamaleia, in a disease of 

 fowls of which it is the cause. The disease is characterized by weakness, drowsi- 

 ness and diarrhoea : post mortem, the alimentary canal is hyperaemic and the small 

 intestine contains a yellowish-grey liquid which may be blood-stained ; the vibrio 

 is found in very large numbers in this fluid. As a rule, the organism does not gain 

 access to the blood stream, though in young fowls affected with the disease it may 

 be isolated from the blood. 



Experimental inoculation. Guinea-pigs are more susceptible to the Metchnikoff 

 vibrio than to the cholera vibrio ; intra-peritoneal and sub-cutaneous inoculation 

 and ingestion even without previous alkalinization of the gastric contents all 

 lead to a fatal result. 



The Metchnikoff vibrio kills young fowls whatever the channel of infection : 

 simple ingestion alone is fatal. Adult birds are much less susceptible and cannot 

 be infected by feeding. Pigeons though very susceptible to sub-cutaneous or intra- 

 muscular inoculation resist infection when fed with the organism. 



Ingestion of the vibrio is harmless to man. 



Microscopical appearance. Morphologically the Metchnikoff vibrio is similar to 

 the cholera vibrio : it is motile and has a single flageilum ; sometimes spirals of 

 4 or 5 turns are seen. 



Cultural characteristics. The Metchnikoff vibrio grows on all the ordinary media 

 and the growths are similar to those of the cholera vibrio. On potato, it grows 

 more abundantly than the cholera vibrio and forms a yellow- brown streak. Cul- 

 tures in milk ultimately become very acid and the casein is coagulated about the 

 eighth day. 



Biological properties. The Metchnikoff vibrio produces indol and nitrites in 

 peptone solutions and gives a very marked nitroso-indol reaction. Guinea-pigs, 

 pigeons and fowls can be immunized by the inoculation of cultures killed by heat 

 at 120 C. 



