. Bulletin of the Department of Agriculture. Agriculture; Agriculture. Washington, D. C. PROFESSIONAL PAPER April 25, 1921 THE SPOROGENES TEST AS AN INDEX OF THE CONTAMINATION OF MILK. By S. Henry Ayees and Paul W. Clemmer, of the Dairy Division. CONTENTS. Page. Present status of the sporogenes test- 1 The Savage method 3 The Weinzirl method „_ 6 Defects in the sporogenes test 7 Attempts to improve the characteris- tic stormy reaction 9 Use of 20 c. c. quantities of milk in the sporogenes test 11 The sporogenes test in relation to milk produced under extreme con- ditions of cleanliness an
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. Washington, D. C. PROFESSIONAL PAPER April 25, 1921 THE SPOROGENES TEST AS AN INDEX OF THE CONTAMINATION OF MILK. By S. Henry Ayees and Paul W. Clemmer, of the Dairy Division. CONTENTS. Page. Present status of the sporogenes test- 1 The Savage method 3 The Weinzirl method „_ 6 Defects in the sporogenes test 7 Attempts to improve the characteris- tic stormy reaction 9 Use of 20 c. c. quantities of milk in the sporogenes test 11 The sporogenes test in relation to milk produced under extreme con- ditions of cleanliness and of filth_ 12 Page. Conditions of production of pasteur- ized milk as indicated by the spo- rogenes test 14 The source of the majority of spores of B. enteritidis sporogenes found in milk 16 Summary and conclusions 19 Literature cited 20 PRESENT STATUS OF THE SPOROGENES TEST. The sporogenes test is based on the characteristic milk reaction produced by certain anaerobic spore-forming bacteria which are widely distributed in nature and which are particularly common in fecal material. Numerous names have been given to anaerobic bacteria that give the typical milk reaction, some of which are the following: B. ente- ritidis sporogenes (Klein) ; B. aerogenes capsulatus (Welch), syno- nym B. welchii (Migula) ; B. perfring ens (Yeillon and Zuber) ; and B. Saccharobutyricus immobilis (Schattenfroh and Grass- berger). It is generally believed that the organisms bearing these names are either identical or very closely related species. In milk, under anaerobic conditions, these organisms produce what is known as the " stormy " fermentation. In a characteristic reaction the casein is coagulated and the curd torn by gas within 24 hours at 37° C. The whey is usually quite clear and the odor of butyric acid is noticeable. When the milk in a test tube is covered with a paraffin plug the latter is usually forced up almost to the top of the tube and sometimes entirely out of the tub
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