134 STUDY AND IDENTIFICATION OF BACTERIA 



of the spirilla. An acid reaction of the faeces, such as that induced by lactic acid 

 bacteria, would apparently be of value in the prophylaxis of cholera carriers. 



Greig has found infection of the bile of the gall-bladder or ducts in 80 cases in 

 271 cholera autopsies. While cholera spirilla are soon crowded out by intestinal 

 bacteria, thus explaining the short period during which cholera spirilla are excreted 

 by convalescents, this is not true when the cholera vibrio gets into the bile ducts or 

 gall-bladder, where ideal conditions prevail for a prolonged life. In fact bile has 

 recently been recommended as a selective medium for cholera enrichment. Greig 

 found one cholera convalescent excreting cholera vibrios forty-four days after the 

 attack. Of 27 persons who had been in contact with cholera patients 6 were ex- 

 creting cholera vibrios though apparently well. 



To identify such spirilla immunity reactions are necessary: 



1. Injected intraperitoneally into guinea-pigs, it produces a peritonitis and sub- 

 normal temperature. This reaction exists for spirilla other than the true cholera 

 spirillum. 



2. Intramuscular injections into pigeons are only slightly pathogenic, if at all. 



3. The agglutination test is the most practical. In this we use serum from an 

 immunized animal, in dilution of from 100 to 1000. It is rare that true cholera 

 vibrios fail to agglutinate in serum of i to 500 and even sera of i to 10,000 dilution 

 give the reaction. Serum of cholera convalescents may show agglutination as early 

 as the tenth day; it is usually best shown about the third week. Dunbar's quick 

 method is very practical. Make two hanging-drop preparations, using mucus from 

 the stool as the bacillary emulsion. To one add an equal amount of a i : 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. 



On the whole the reports from the use of anticholera sera are not 

 very encouraging. Savas, however, was favorably impressed by such 

 treatment during the Balkan war. It should be administered intra- 

 venously and early in the attack and given in doses of 50 c.c. Of 61 

 severe cases so treated the mortality was 55.7%. Of 17 severe cases 

 not receiving serum treatment all died. 



Prophylactically, there are three prominent methods: i. That of Haffkine, where 

 live cholera spirilla are injected subcutaneously; and 2. Strong's cholera autolysate. 

 In this cholera cultures are killed at 6oC. The killed culture is then allowed to 

 digest itself in the incubator at 37C. for three or four days (peptonization). The 

 preparation is then filtered and from 2 to 5 c.c. of the filtrate is injected. Ferran 

 was the first to use vaccines. 



