BACTERIUM COLL 247 



is done by Bact. typhi. But if ammonia was the source 

 of the nitrogen, then only the Bact. typhi and one Bact. 

 coli isolated from man produced levorotatory lactic acid 

 in ;i remarkable manner; both the other coli cultures (from 

 cheese and animal feces) produced dextrorotatory lactic 

 acid. 



(<•/) Vigorous production of H 2 S from peptone; usu- 

 ally abundant indol. We have never failed to find traces 

 of indol. 



Karplus found, in the urine of a patient, an organism resembling 

 the typhoid bacterium, which produced H 2 S and methylmercaptan 

 abundantly from the substances containing sulphur in the urine (C. 

 B. xvi. 701). 



(e) Decomposition of urea occurs with many cultures, 

 but by no means in all (Barlow, Mann). Compare page 

 70. Halle and Dissard, and recently Mann, have demon- 

 strated very minutely the decomposition of urea. Kashida 

 found it so constant that he described the production of 

 ammonia in a lactoso-urea nutrient medium as a charac- 

 teristic peculiarity as opposed to Bact. typhi (C. B. xxi, 

 802), while Melchior (Cystitis und Urininfektion, Berlin, 

 1897) considers the Bact. coli to be the most common 

 of cystitis (after previous injury to the bladder), 

 but denies that it can produce ammonia by breaking up 

 urea. Similar negative results were previously obtained 

 l.v Schnitzler and Krogius. 



Distribution. — 



(a) Outside the body: In canal-water, impure water, 

 but also in springs which can scarcely be suspected of 

 pollution, there occur very often organisms which corre- 

 spond to Bact. coli (v. Freudenreich, Lehmann and 

 Neumann). We never failed to find them in water sus- 

 pected of containing typhoid bacteria. 



The narrower the definition is made, so much the more is the 

 number reduced. Thus, for example, Schardinger (C. B. xvi, 8o3) 

 <It < lans water organisms, resembling Bact. coli, which ferment grape- 

 su^ar and grow in the incubator, to be frequently present, but in 

 spite of it that the Bact. coli is rare. Most of the producers of fer- 

 mentation are easily differentiated from the Bact. coli by the milk- 

 white, slimy, tenacious growth upon plates (see below). 



Regarding the occurrence in dough, compare page 255. 



