358 TYPHOID FEVER 



to arrive at the type most frequently present in the human 

 intestine. 



Two standards may be alluded to. First, that of an English 

 Committee which reported in 1904 on the standardisation of 

 methods for the bacterioscopic examination of water. According 

 to this, the b. coli is a small, motile, non-sporing bacillus, 

 capable of growing at 87° C, Gram-negative, never liquefying 

 gelatin, producing clot and permanent acidity of milk within 

 seven days at 37°, fermenting glucose and lactose, with, in both, 

 acid and gas formation, — subsidiary points being the forma- 

 tion of indol, the formation of a thick yellowish-brown growth 

 on potato, production of fluorescence in neutral-red, reduction of 

 nitrates, and fermentation of saccharose. A similar American 

 Committee looked upon the typical organism as a non-sporing 

 bacillus, motile, fermenting dextrose-broth, with the formation, 

 in the closed limb of the fermentation tube, of about 50 per 

 cent, of gas, of which about one-third is carbon dioxide, causing 

 acid and clot in milk in forty-eight hours, not liquefying gelatin, 

 producing indol and reducing nitrates. These two standards 

 differ in the fact that the English Committee lay less weight on 

 indol formation and the reduction of nitrates. 



It may be said that, in addition to the type characters, 

 lactose- fermenters from the human intestine usually ferment 

 saccharose and dulcite and have no effect on adonite, inulin, and 

 inosite, and it may be, no influence on mannite. 



Pathogenic Properties of the B. coli. — In man, the b. 

 coli has been found as the only organism present in various 

 suppurative conditions (see Chapter VII.), especially in con- 

 nection with the intestine {e.g., appendicitis) and about the 

 urinary tract. In the latter, it is also responsible for catarrhal 

 conditions in the pelvis of the kidney and in the bladder, these 

 being more common in the female, and frequently presenting 

 chronic characters. As a practical point, it may be said that 

 the treatment of the latter by vaccines, especially when made 

 from the strain isolated from the lesion, has sometimes been 

 attended with success. The b. coli is also apparently the cause 

 of some cases of summer diarrhoea (cholera nostras), of some 

 cases of infantile diarrhoea, and of some food poisonings. 



The Pathogenicity of the B. coli and its Relation to that of the 

 Typhoid Bacillus. — Intraperitoneal injection in guinea-pigs is often 

 fatal. Subcutaneous injection may result in local abscesses, and some- 

 times in death from cachexia. Sauarelli found that the b. coli isolated 

 from typhoid stools was much more virulent than when isolated from 

 the stools of healthy persons. He holds that the increase in virulence is 

 due to the effect of typhoid toxins. This increased virulence of the 



