SPIRILLUM CHOLERA ASIATICS 125 



Cholera is diagnosticated bacteriologically by cultivation of 

 the stools. The organisms are present in almost pure culture, 

 and can be made to grow quite easily. There are several 

 other spirilla of similar form and manner of growth, and some- 

 times delicate biological tests (see below) are necessary. 

 Agglutination tests may be used in this disease, as some 

 clumping power is acquired by the blood during an attack. 

 Another antibody, a bacteriolysin, is formed, which has the 

 power of dissolving the cholera spirilla. Animals injected 

 with the cholera organisms also acquire this power. If a 

 guinea-pig be injected with spirilla up to a point where it will 

 resist large numbers, its blood serum will dissolve the living 

 organisms either in the test-tube or, what is better, within the 

 abdominal cavity of another guinea-pig. In the latter case 

 the antiserum from the prepared guinea-pig and living rods 

 are mixed and injected together into the peritoneal cavity. 

 The rods are devitalized and the pig lives, although another 

 animal receiving the organisms in like quantity, but without 

 serum, will die. This is the method suggested which can be 

 used to identify suspected cultures, using as the protective 

 blood serum that from an animal previously treated with 

 known cholera germs. 



The cholera spirillum is a curved organism something the 

 shape of a comma, and is sometimes called the comma 

 bacillus. One end is apt to be thicker than the other. It 

 sometimes appears like an S when two are joined on end. 

 Long filaments may be seen in fluids. In old laboratory 

 cultures it may appear as a short, straight rod or club. It is 

 actively motile by means of a long single flagellum on the end. 

 No spores are formed. It measures from 8~oVo ^ 5 0*0 o 

 inch in length by 75 Q 00 inch in width. It is not easy to 

 measure since spirilla are not simple curves but spirals. It 

 does not stain with great ease, but a weak watery solution 

 of fuchsin is the best. It grows best in the presence of oxygen 

 at 37.5 C. or 98 F., but may grow at ordinary temperatures. 

 It has the power of digesting gelatin and solidified blood serum 



