CHOLERA. 97 



using mucus from the stool as the bacillary emulsion. 

 To one add an equal amount of a 1:50 normal serum; 

 to the other a i : 500 dilution of immune serum. Cholera 

 spirilla remain motile in the control, but lose motility and 

 become agglutinated in the preparation with the immune 

 serum. 



4. Pfeiffer's phenomenon. If cholera spirilla are introduced 

 into the peritoneal cavity of immunized guinea-pigs (or if 

 together with a i : 1000 dilution of immune serum the 

 mixture is injected intraperitoneally into normal guinea- 

 pigs) and at periods of ten to sixty minutes after injection, 

 material is removed by a pipette from the peritoneal 

 cavity, the spirilla have lost motility, have become granular 

 and degenerated. Pseudospirilla are unchanged. This 

 reaction may be carried on in a pipette, using fresh serum. 

 Antisera for the treatment of cholera have not proved 

 successful. Prophylactically, there are two prominent 

 methods: (T) That of Haffkine, where live cholera spirilla 

 are injected subcutaneously; and (2) Strong's cholera 

 autolysate. In this cholera cultures are killed at 60 C. 

 The killed culture is then allowed to digest itself in the 

 incubator at 37 C. for three or four days (peptonization). 

 The preparation is then filtered and from 2 to 5 c.c. of the 

 filtrate is injected. 

 For diagnosis take a fleck of mucus, make a straight smear and fix; 



stain with a i : 10 carbol fuchsin. The comma shaped organisms 



appear as fish swimming in a stream. 



2. Inoculate a tube of peptone solution. The cholera 

 spirilla grow so rapidly, and being strong aerobes, they 

 grow on the surface of the fluid so that by taking a loopful 

 from the surface, we may in eight hours obtain a pure 

 culture. Inoculate a second tube from this first and, 

 if necessary, a third (enrichment method). 



3. Test for cholera red reaction. (Simply adding from three 

 to five drops of concentrated sulphuric acid in the first 

 or second peptone culture after 18 to 24 hours' growth.) 



