CHAPTER XXII 

 BACILLUS COLL 



Introduction. 



Section I. Experimental inoculation, p. 394. 



Section II. Morphology and cultural characteristics, p. 395. 



Section III. Biological properties, p. 396. 



1. Bio-chemical reactions, p. 396. 2 Variability of flagella, p. 398. 3. Vitality 



and virulence, p. 398. 4. Toxin, p. 398. 5. Vaccination and serum therapy, p. 399. 



6. Agglutination, p. 399. 

 Section IV. Detection, isolation and identification of the colon bacillus, p. 400. 



The bacillus of green diarrhoea, p. 400. 



IN man and the lower animals the colon bacillus, which was. originally 

 described by Escherich, is a normal inhabitant of the alimentary canal where 

 it makes its appearance a few hours after birth. 



In the intestines of healthy human subjects the colon bacillus is associated 

 with numerous other micro-organisms (at least fifty different species are 

 present, many of them being anaerobes) ; it is also frequently found in the 

 mouth twenty-five out of sixty-five cases (Grimbert and Choquet). 



Though often only slightly virulent when isolated from the healthy intestine, 

 the colon bacillus in certain circumstances and in a diseased environment 

 may acquire a high degree of virulence, as for instance in all febrile con- 

 ditions, in enteric fever, and in the majority of diseases of the intestine ; and 

 may then act as the causal agent of a number of diseases affecting man. 



It is, for instance, the cause of secondary infections in enteric fever, dysentery 

 and cholera. 



In some cases of septicaemia the colon bacillus is the organism present in the 

 blood, and while as a rule bacillaemic conditions due to it are not severe, they may on 

 occasions present all the clinical features of enteric fever. The bacillus is also the 

 cause of some attacks of enteritis, of some cases of choleraic and infantile 

 diarrhoaa, etc. Peritonitis may sometimes be due to the colon bacillus (as, for 

 instance, peritonitis resulting from perforation of the gut or following strangulated 

 hernia, and peritonitis unaccompanied by perforation). Invading the biliary 

 passages this organism determines suppurative cholangitis and possibly infective 

 jaundice, and is responsible for some cases of sore throat, broncho-pneumonia, 

 endocarditis, pericarditis, and meningitis. It is the causal agent in a number of 

 infections of the urinary passages and must be identified with the urinary bacillus 

 of Clado. In women it plays an important part in determining pathological con- 

 ditions of the true pelvis (such as salpingitis and metritis). Finally it is responsible 

 for most post mortem and agonic ante mortem infections. 



The colon bacillus is found in the soil, in water contaminated with animal 

 excreta, and in dust. 



