16 BULLETIN WO, U. S. DEPARTMENT 0E AGRICULTURE. 
THE SOURCE OF THE MAJORITY OF SPORES OF B. EXTERITIDIS 
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 seem- logical to assume that most of them come from that source. 
Eace (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. TThile 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 tube- with 20 c. c. of milk, was run 
on sample- 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 mi 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 -imply 
washed with cold water. Small-top pads 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 sample- 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 condition- with sterilized utensils. It would seem from 
these result- that unsterilized utensils do not contribute to any 
marked extent to the contamination of milk by spores of B. ervteri- 
