66o ■ Bacillus Coli 



mula is very constant for the micro-organisms of the colon group 

 and forms one of their most important differential characteristics. 

 In calculating the gas formula Winslow has shown that some care 

 ought to be taken to do it at the appropriate time. According to his 

 observations the given formula only obtains between the twenty- 

 fourth and forty-eighth hours. Before this period the H, which is 

 first formed, preponderates; after it the CO2 may preponderate. 

 In sugar-containing bouillon, acetic, lactic, and formic acids are 

 produced. The colon bacillus does not, as a rule, fermentsaccharose. 

 When a similar bacillus is found regularly to ferment saccharose, it 

 is best to regard it as a subspecies or separate type, for which Dun- 

 ham has introduced the name Bacillus coli communior . 



The bacillus requires very little nutriment. It grows, in Uschin- 

 sky's asparagin solution, and is frequently found living in river and 

 well waters. 



Indol is formed in both bouillon and peptone solutions, but phenol 

 is not produced. The presence of indol is best determined by Sal- 

 kowski's method (?.!'.). 



Toxic Products. — Vaughan and Cooley* have shown that the 

 toxin of the colon baciUus is contained in the germ-cell and under 

 ordinary conditions does not diffuse from it into the culture-medium. 

 The toxin may be heated in water to a very high temperature without 

 injuring its poisonous nature. They have devised an apparatus in 

 which enormous cultures can be prepared and the bacteria pulver- 

 ized, t Of such a preparation 0.0002 gram will kill a 200-gram guinea 



pig- 



Pathogenesis. — The bacillus begins to penetrate the intestinal 

 tissues almost immediately after death, and is the most frequent 

 contaminating micro-organism met with in cultures made at autopsy. 

 It may spread by direct continuity of tissue, or ma the blood-vessels. 



Although under normal conditions a saprophyte, the colon bacillus 

 is not infrequently found in the pus in suppurations connected with 

 the intestines — as, for example, appendicitis-r-and sometimes in 

 suppurations remote from them. 



In intestinal diseases, such as typhoid, cholera, and dysentery, 

 the bacillus not only seems to acquire an unusual degree of virulence, 

 but because of the existing denudation of mucous surfaces, etc., finds 

 it easy to enter the general system, with the formation of remote 

 secondary suppurative lesions in which it is the essential factor. 

 When absorbed from the intestine, it frequently enters the kidney 

 and is excreted with the urine, causing, incidentally, local inflamma- 

 tory areas in the kidney, and occasionally cystitis. A case of ure- 

 thritis is reported to have been caused by it. 



The bile-ducts are sometimes invaded by the bacillus, which may 

 lead to inflammation, obstruction, suppuration, or calculus formation. 



* "Jour. Amer. Med. Assoc," 1901; "American Medicine," 1901. 

 t "Trans. Assoc. Amer. Phys.," 1901. 



