BILE COMPARED WITH LACTOSE BOUILLON FOR 



DETERMINING THE PRESENCE OF B. COLI 



IN WATER 



MAUD MASON OBSTi 



Irregular results have often been obtained in the past in the 

 routine bacteriological examinations of water. The presumptive 

 test for B. coli made with lactose peptone ox-bile upon a sample 

 of water would give no indication of gas in 10 cc. quantities on 

 one day, while another sample from the same source would show 

 gas in 1 cc. or in 0.1 cc. quantities on the following day. It was 

 observed that when bile which had been stored for six weeks 

 at 1°C. was used for four samples of water from a polluted spring, 

 and bile which had been freshly collected was used for six 

 samples from the same spring, the former produced no gas, 

 while the latter produced gas in 0.1 cc. quantities. Similar 

 results were obtained with the use of bile which had apparently 

 been carelessly collected. 



In this laboratory it had been found necessary to obtain bile 

 from an abattoir in a nearby city in 5-gallon lots, and to depend 

 upon the workers in the abbatoir for its collection. When 

 received at the laboratory, the bile was sterilized and stored at 

 1°C. until used, which was frequently for two months or longer. 

 The above results showed that it must be collected more fre- 

 quently and by one who would use proper precautions. This 

 required one-half day's time every week of a reliable helper, and 

 an expenditure of fifty (50) cents for three gallons. Even then, 

 the helper met with serious difficulties in gaining access to that 

 part of the abattoir in which he could secure the unbroken gall 

 bladder. 



1 This work was carried on under the auspices of the Microbiological La))ora- 

 tory, Bureau of Chemistry, Washington, D. C. The author desires to acknowl- 

 edge the valuable assistance rendered by Dr. Charles Thorn in the preparation of 

 this paper. 



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