Detection of the Organism 577 



never found in the blood or tissues, but only in the intestine, where 

 they frequently enter between the basement membrane and the 

 epithelial cells, and aid in the detachment of the latter. 



IssaefE and Kolle found that when virulent cholera spirilla are 

 injected into the ear-veins of young rabbits the animals die on the 

 following day with symptoms resembling the algid state of human 

 cholera. The autopsy in these cases showed local lesions of the 

 small intestine very similar to those observed in cholera in man. 



Guinea-pigs are susceptible to intraperitoneal injections of 

 the spirillum, and speedily succumb. The symptoms are rapid 

 fall of temperature, tenderness over the abdomen, and collapse. 

 The autopsy shows an abundant fluid exudate containing the micro- 

 organisms, and injection and redness of the peritoneum and viscera. 



Specificity. — The cholera spirillum is present in the dejecta 

 of cholera with great regularity, and as regularly absent from the 

 dejecta of healthy individuals and those suffering from other dis- 

 eases. No satisfactory proof of the specific nature of the organ- 

 isms can be obtained by experimentation upon animals. Ani- 

 mals are never affected by any disease similar to cholera during 

 epidemics, nor do foods mixed with cholera discharges or with pure 

 cultures of the cholera spirillum affect them. Subcutaneous in- 

 oculations do not produce cholera. 



Detection of the Organism. — It often becomes a matter of im- 

 portance to detect the cholera spirilla in drinking-water, and, as 

 the number in which the bacteria exist in such a liquid may be 

 very small, diflSculty may be experienced in finding them by ordi- 

 nary methods. One of the most expeditious methods is that 

 recommended by Loffler, who adds 200 cc. of the water to be 

 examined to 10 cc. of bouillon, allows the mixture to stand in an 

 incubator for from twelve to twenty-four hours, and then makes 

 plate cultures from the superficial layer of the liquid, where, if 

 present, the development of the spirilla will be most rapid because 

 of the free access of air. 



Gordon* employs a medium composed of lemco i gram, peptone 

 I gram, sodium bicarbonate o.i gram, starch i gram, and distilled 

 water 100 cc. for the differentiation of the cholera and Finkler- 

 Prior spirilla. If the medium be tinted with litmus and the cultures 

 grown at 37°C., a strongly acid change is produced by the true 

 cholera organism in twenty-four hours. The Finkler-Prior spirillum 

 produces but slight acidity, which first appears about the third 

 day. 



The identification of the cholera spirillum, and its differen- 

 tiation from spiral organisms of similar morphology obtained 

 from feces or water in which no cholera organisms are expected, is 

 becoming less and less easy as our knowledge of the organisms 

 increases. The following points may be taken into consideration: 



* " British Medical Journal," July 28, 1906. 

 37 



