Pathogenesis 575 



According to Frankel, the organisms in the liquefied cultures all 

 die in eight weeks, and cannot be transplanted. Kitasato, how- 

 ever, has found them living and active on agar-agar after from 

 ten to thirty days, and Koch occasionally found some alive after 

 two years. 



This low vital resistance of the microbe is very fortunate, for 

 it enables us to establish satisfactory quarantine for the prevention 

 of the spread of the disease. Excreta, soiled clothing, etc., are 

 readily rendered harmless by the proper use of disinfectants. Water 

 and food are rendered innocuous by boiling or cooking. Vessels 

 may be disinfected by thorough washing with jets of boiling water 

 discharged through a hose connected with a boiler, and baggage 

 can be sterilized by superheated steam. 



Metabolic Products. Indol is one of the characteristic metabolic 

 products of the cholera spirillum. As the cholera organisms also 

 produce nitrites, all that is necessary to demonstrate its presence in 

 a colorless solution is to add a drop or two of chemically pure sul- 

 phuric acid, when the well-known reddish color will appear. 



The organism also produces acid in milk and other media. Bitter 

 has also shown that the cholera organism produces a peptonizing 

 and probably also a diastatic ferment. 



Toxic Products. Rietsch thinks the intestinal changes depend 

 upon the action of the peptonizing ferment. Cantani, Nicati and 

 Rietsch, Van Ermengem, Klebs, and others found toxic effects 

 from cultures administered to dogs and other animals. Several 

 toxic metabolic products of the spirilla have been isolated. Brieger,* 

 Brieger and Frankel, f Gamaleia,f Sobernheim, and Villiers have 

 studied more or less similar toxic products. The real toxic sub- 

 stance is, however, not known. 



Pathogenesis. Through what activity the cholera organism 

 provokes its pathogenic action is not yet determined. The organ- 

 isms, however, abound in the intestinal contents, penetrate spar- 

 ingly into the tissues, but slightly invade the lymphatics, and 

 almost never enter the circulation; hence it is but natural to conclude 

 that the first action must be an irritative one depending upon toxin- 

 formation in the intestine. 



In the beginning of the disease the small and large intestines 

 are deeply congested, almost velvety in appearance, and contain 

 liquid fecal matter. The patient suffers from diarrhea, by which 

 the feces are hurried on and become extremely thin from the ad- 

 mixture of a copious watery exudate. As the feces are hurried out, 

 more and more of the aqueous exudate accumulates, until the intes- 

 tine seems to contain only watery fluid. The solitary glands and 

 Peyer's patches are found enlarged and the mucosa becomes macer- 



* "Berliner klin. Wochenschrift," 1887, p. 817. 



" Untersuchungen iiber die Bakteriengifte," etc., Berlin, 1890. 

 j "Archiv de med. exp.," rv, No. 2. 

 "Zeitschrift fur Hygiene," 1893, XIV > I 45- 



