16 BULLETIN &40, TJ. S. DEPARTMENT OF AGRICULTURE. 



THE SOURCE OF THE MAJORITY OF SPORES OF B. ENTERITIDIS 

 SPOROGENES FOUND IN MILK. 



It is known that the spores of B. enteritidis sporogenes are widely 

 distributed in nature. As stated, they are found in cow manure, 

 cattle feed, soil, and water. In fact, they are so generally distributed 

 that their presence in milk may be interpreted theoretically as con- 

 tamination from a number of sources. Perhaps they come from 

 various sources, but since they are present in manure in larger num- 

 bers than in other material likely to serve as a source of contamination, 

 it seems logical to assume that most of them come from that source. 



Race (10) believes, however, that in practice milk cans form a most 

 fruitful source of these organisms. He offers no figures to support 

 his belief, which, if true, naturally would decrease the value of the 

 test as a means of detecting manurial contamination. While con- 

 tamination by dirty utensils is extremely important from the stand- 

 point of number of bacteria introduced, it is not usually of so serious a 

 nature as that of cow manure. In the consideration of the sporogenes 

 test the influence of utensils, however, can not be overlooked, and a 

 number of samples were run to determine the importance of this 

 factor. 



The sporogenes test, using 10 tubes with 20 c. c. of milk, was run 

 on samples of milk produced under dirty conditions with unsteril- 

 ized utensils. A similar number of tests were then made on milk 

 produced under the same conditions, but with sterilized utensils. 

 Then a third set of tests was made on milk produced from cows 

 which had been cleaned and which were kept clean, but for which 

 the utensils were not sterilized. In fact, the utensils were simply 

 washed with cold water. Small-top pails were used when the cows 

 were clean, in order to exclude as much manure as possible. 



From the results of this work, which are shown in Table 6, it will 

 be seen that, taking the samples as a whole, there was very little 

 difference in the sporogenes test between samples produced under 

 dirty conditions with the utensils not sterilized and those produced 

 under dirty conditions with sterilized utensils. It would seem from 

 these results that unsterilized utensils do not contribute to any 

 marked extent to the contamination of milk by spores of B. enteri- 

 tidis sporogenes. 



