THE TYPHOCOLON BACILLI 169 



may be the most numerous. It is probable that this 

 organism alone is able to inflame the peritoneum, as 

 it certainly can produce localized and diffuse pus 

 collections. The colon bacillus is frequently the only 

 organism found in acute appendicitis. It has been 

 found as an important factor if not the sole cause in 

 pneumonia and pleurisy. It has been found to cause 

 meningitis and endocarditis. 



No antiserum of practical value has been produced 

 by the injection of these organisms into the lower 

 animals. On the other hand, some success has been 

 attained in establishing active immunity both as a 

 preventive and as a remedial agency by injecting 

 increasing quantities of dead bacteria. 



Diagnosis. Colon infections are diagnosticated chiefly 

 by finding the organism. They are present in the 

 fibrinous exudate or pus, and in the blood in septi- 

 cemia. We grow some of this in ordinary nutrient 

 broth or jelly, and isolate in pure culture. Colon 

 bacilli are, of course, easily obtained from the stools. 

 The agglutination or clumping test can also be used 

 in colon bacillus infections, since agglutinins are formed 

 during an attack. Pus or other bacteria containing 

 substances should be disinfected by mixing with 5 per 

 cent, carbolic acid and allowing it to act for at least 

 one-half hour. 



Paracolon Bacilli. These organisms resemble the 

 Bacillus coli communis so closely that only the dif- 

 ferences need be noted. They are more actively 

 motile, they do not coagulate milk but probably pro- 

 duce alkalinity in it; they are capable of producing acid 

 and gas in only three of the sugars. They differ from 



