Sterol Requirement for the Growth of Treponema hyodysenteriae

Abstract
The addition of cholesterol to a liquid medium containing bovine serum albumin (BSA) fraction V or acetone-delipidized BSA fraction V instead of serum stimulated the growth of T. hyodysenteriae, a serum-requiring spirochaete associated with swine dysentery. As little as 1.25 .mu.g cholesterol ml-1 increased viable counts about 1000-fold. Sitosterol and cholestanol, but not pregnenalone, cholestenone or stigmasterol, produced a growth response comparable to that of cholesterol. T. hyodysenteriae apparently requires a sterol for growth.