2 BULLETIN 940, U. S. DEPARTMENT OF AGRICULTURE. 



English bacteriologists have made use of this characteristic reac- 

 tion, both in water and milk analysis, in order to detect the presence 

 of B. enteritidis sporogenes, which in their opinion indicates con- 

 tamination by fecal material. The test has consequently become 

 known as the sporogenes test. Therefore, in this paper the name B. 

 enteritidis sporogenes will be used in designating the organism caus- 

 ing the stormy reaction, except when direct reference is made to pub- 

 lications in which different terms are used. The organisms giving 

 this test should not be confused with B. sporogenes of Metchnikoff, 

 which gives an entirely different milk reaction. 



Whether the bacteria which show the sporogenes test are identical 

 makes little difference provided their distribution in nature is about 

 the same. They are known to be present in fecal material, in miscel- 

 laneous foodstuffs, cattle feed, soil, and water. Since they are present 

 in cow feces, it is natural to assume that their presence in milk may 

 be used as an index of contamination by manure. If they are present 

 in feeds and soil to the same extent as in manure, their presence in 

 milk may be rather an index of the general condition of cleanliness 

 of production. 



The obvious advantage of using the spores of B. enteritidis sporo- 

 genes as an index of contamination lies in the fact that pasteurization 

 does not destroy them, and therefore does not interfere with the de- 

 termination of their presence in milk. Furthermore, they are not 

 believed to vegetate in milk under normal conditions, and vegetative 

 cells do not sporulate in the presence of the fermentable sugar in 

 milk ; so the sporogenes test with both fresh and old milk, provided 

 it is still sweet, should give the same results. The test has conse- 

 quently become known as a " nonmulti plying test." Should it prove 

 to be reliable in gauging the cleanliness of production and be rela- 

 tively accurate, it would be extremely valuable in milk-control work. 



It has not been difficult to find spores in milk which give the char- 

 acteristic stormy reaction. Fliigge (4) 1 in 1894 isolated anaerobic 

 butyric-acid bacteria from milk. In 1897 Klein (8) examined milk 

 in London for spores of B. enteritidis sporogenes and found them in 

 8 of the 10 samples examined. Since then they have been found in 

 milk by various investigators, among whom are Savage (12), Hous- 

 ton (7), Barthel (1), Brown (2), Simonds (14), Eitchie (11), Pryor 

 (9), Weinzirl (15) , Shippen (13) , and Ford (5). Probably spores of 

 these anaerobic bacteria can be found in all milk if large enough 

 amounts are examined. 



There seems to be a difference of opinion among different investi- 

 gators as to the value of the sporogenes test in indicating manurial 

 contamination and the general conditions of cleanliness in produc- 



1 The numbers in parentheses refer to " Literature cited," at end of bulletin. 



