VIBRIO METCHNIKOVI 525 



duced experimentally in new-born rabbits by feeding, and in young guinea-pigs 

 by Koch's procedure. Pathogenic on ip. or iv. inoculation into guinea-pigs, rabbits, 

 and mice, but not as a rule into pigeons. One loopful of an 18-hours' agar culture 

 of a virulent strain injected ip. into a young guinea-pig is fatal within 24 hours. 

 P.M. congestion of peritoneal and pleural cavities with some sero-sanguineous 

 fluid. Small gut congested ; may be fibrin over the abdominal viscera. Vibrios 

 may or may not be cultivated from the peritoneal cavity. If a large dose is given 

 the vibrios can be recovered from the peritoneal fluid and the heart blood. Iv. 

 injection of five loopfuls of an 18-hour agar culture of a virulent strain into rabbits 

 is fatal in 48 hours or less. P.M. small gut congested and contains thin fluid. 

 Vibrios generally recoverable from the blood. No true exotoxin formed, but dis- 

 integrated bodies of bacilli are very toxic to animals. Virulence rapidly falls on 

 artificial cultivation. 



Finkler-Prior's Vibrio proteus. — Isolated by Finkler and Prior (1884) from the old 

 putrid excreta of a patient suffering from gastro-enteritis. Morphologically and cul- 

 turally it resembles the cholera vibrio, but it can be differentiated by serological reactions, 

 and by its failure to give the cholera-red reaction. Has frequently been found in water. 



Deneke's Vibrio tyrogenus. — Found by Deneke (1885) in cheese. Resembles the 

 cholera vibrio, but liquefies gelatin more rapidly, grows poorly or not at all on potato, 

 and does not give the cholera-red reaction. 



Vibrio metchnikovi. — Isolated by Gamaleia (1888a) from the blood and intestinal 

 contents of chickens dying from a cholera-hke disease at Odessa. Resembles the cholera 

 vibrio very closely ; gelatin is liquefied more rapidly ; growth on MacConkey is poorer. 

 Cholera-red and other biochemical reactions are identical with those of V. cholerce. It 

 is much more invasive when injected into animals, killing guinea-pigs injected subcutane- 

 ously, and pigeons injected intramuscularly (see Pathogenicity). Can be separated from 

 V. cholerce by agglutination and Pfeifler's reactions. Has been isolated from water. 



Vibrio phosphorescens. — Isolated by Dunbar (1893) from the Elbe in 1893. Shown 

 by Kutscher (1893) to exhibit phosphorescence in the dark. This occurs on ordinary 

 media at 22° C, reaching its maximum in 24 to 48 hours in gelatin, broth, or peptone 

 water, and disappearing rapidly. It is a function of the living bacilli. Phosphorescence is 

 not visible in cultures incubated anaerobically. V. phosphorescens grows in, and liquefies 

 gelatin, more rapidly than V. cholerce. Grows very poorly or not at all on potato. Hsemo- 

 lytic and diastatic ; produces indole ; gives acid in glucose, mannitol, lactose, and later 

 maltose (Jermoljewa 1926). It has been isolated from human faeces (Jermoljewa 1926). 



El Tor Vibrio. — Isolated by Gotschhch (1906) in 1905 from six pilgrims who had died 

 of dysentery or gangrene of the colon at the Tor quarantine station on the Sinai Penin- 

 sula. Forms soluble hsemolysin for sheep and goat cells. Gives atypical Pfeiffer 

 reaction (Neufeld and Haendel 1907). Usually gives positive Voges-Proskauer reaction 

 (van Loghem 1938). Killed vibrios injected intraperitoneally are said to be more toxic 

 for the rat than killed cholera vibrios (see van Loghem 1938). According to Takita (1939) 

 the El Tor vibrio produces a true thermolabile exotoxin, distinct from the hsemolysin, 

 and proving fatal to mice on intraperitoneal inoculation. Relation to V. cholercB stiU 

 doubtful (see Fig. 104). 



Vibrio berolinensis. — Isolated by Neisser (1893) from water to which cholera vibrios 

 had intentionally been added. Resembles the cholera vibrio closely ; gelatin colonies 

 are smaller and animal pathogenicity is low. But probably it is merely a variant of 

 the true cholera vibrio. Similarly the " Vibrio ivanofl " (Ivanoff 1893), which was cul- 

 tured from the faeces of a typhoid patient to which cholera vibrios had been added, and 

 which differed in unimportant particulars from the cholera vibrio, is also a variant of 

 the true cholera vibrio (Dieudonn6 1894). 



