DESTRUCTION OF BOTULINUM TOXIN BY MILK BACTERIA

DESTRUCTION OF BOTULINUM TOXIN BY MILK BACTERIA* J. M. SHERMAN, C. N. STARK AND PAULINE STARK CornvU University, Ithaca, New York Data have been published elsewhere, (Sherman, Stark, and Stark, (8)) which show a definite, though slight, destruction of botulinum toxin by intestinal bacteria. The intestinal bacteria studied are also commonly found in milk. The present paper reports work of a similar nature dealing with other types of milk bacteria in pure culture together with some observations on the action of a mixed flora. The unique freedom of milk and milk products as agents in the dissemination of botulism is of great interest. Although fresh milk may ordinarily be used before bacterial growth has been sufficiently extensive to be dangerous from the standpoint of botulinum poisoning, such is not at all the case with cheese and certain other milk products. Indeed, from the standpoint of chemical composition, cheese would appear to be an excellent medium for the production of this toxin. The explanation which might appear valid is that the acidity of most types of cheese is sufficiently high to inhibit the growth of Clostridium botulinum but such an explanation would not hold for all types of cheese, and from some of the experimental results which have been published concerning the acid limits for growth of this organism, would indicate that a complete explanation cannot be founded entirely on the basis of acidity in the ease of any type of cheese. Jordan (5) puts the acid limit of growth of Clostridium botulinum at pH 4.9. It is well known that milk develops a lower pH than this after it is coagulated by acid in normal souring. This, however, would not account for the disposition of the toxin which might be produced while Clostridium botulinum is growing, before sumeient acid is produced to inhibit its * Received for publication May 5, 1928. 352

DESTRUCTION OF BOTULINUM TOXIN BY MILK BACTERIA

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