82 ABSTRACTS 



The Characteristics of Bacteria of the Colon Type Occurring in Human 



Feces. L. A, Rogers, Wm. Mansfield Clark, and H. A. Lubs. 



A total of 113 cultures were obtained from 17 individuals and classi- 

 fied on the basis of carbon-dioxid hydrogen ratio, indol formation, 

 gelatin liquefaction and the fermentation of certain carbohydrates 

 and alcohols. All but 6 of the 113 cultures fermented glucose in the 

 absence of oxygen with the production of almost exactly equal volumes 

 of carbon dioxid and hydrogen. 



This ratio agrees with that given by 99 per cent of the cultures 

 obtained from bovine feces and differs radically from that given by 

 nearly all of the grain cultures. Further agreement with the bovine 

 feces cultures is seen in the high percentage of indol formers, the absence 

 of gelatin liquefiers, a low percentage of carbohydrate fermenters but 

 a relatively high ability in fermenting the alcohols. 



The remaining six cultures produce nearly twice as much carbon dioxid 

 as hydrogen and otherwise agree in a general way with the high ratio 

 group which predominated in the grain cultures. 



While this type occurred in relatively small numbers the actual 

 number may amount to several hundred thousand in each gram of 

 material. It is possible that the more frequent occurrence outside 

 of the animal body of the high ratio type may be because it is more 

 resistant to unfavorable conditions and consequently survives after 

 the low ratio type has disappeared. 



The Ttjpe of Colon Bacillus Occurring in Surface Waters. L. A. Rogers. 



A collection of 137 cultures of the colon type isolated from waters of 

 greatly varying degrees of contamination were separated into two dis- 

 tinct groups. One of these included about one-third of the cultures 

 and was evidently identical with the type which has been found to 

 include 95 to 99 per cent of the colon bacilli of bovine and human 

 feces. This type was found occasionally in springs in which there was 

 no evident source of contamination but was especially abundant in 

 rivers and streams usually considered to be polluted with sewage. 



The second group which occurred in practically all waters examined 

 was identified with a type which, while it responds to all of the usual 

 tests for B. coli, occurs in feces in relatively small numbers. Cultures 

 isolated from grains belonged almost exclusively to this type. The 

 significance of this type in water cannot be determined but the charac- 

 teristic fecal colon type can be demonstrated in polluted water with 

 reasonable certainty. 



Some Problems in Bacterial Nomenclature. R. E. Buchanan. 



The following conclusions are reached: 



1. A standing committee of the society, either the committee on 

 classification or a new committee should be asked to consider problems 

 of bacterial nomenclature and make suitable recommendations to the 

 societv. 



