Antagonistic effect on Clostridium botulinum type E by organisms resembling it.

A bacteriocin-like substance, active against strains of Clostridium botulinum type E, is produced by certain nontoxic organisms whose biochemical properties and morphological characteristics are similar to type E. The substance, for which the name "boticin E" is proposed, is bacteriolytic for vegetative cells and bacteriostatic for spores of type E. Its spectrum of activity is somewhat strain-specific. Of the clostridial species tested, only C. botulinum type E and, to a lesser extent, C. perfringens and C. acetobutylicum, but not C. botulinum types A, B, or F, are sensitive. Irreversibly resistant variants originating from both vegetative cells and spores of certain strains were obtained. The active substance is heat-stable and dialyzable, and is not inactivated by chloroform but is digested by trypsin. Ethyl alcohol and acetone precipitates are fully active, whereas trichloroacetic acid precipitates are only partially active. Other nontoxic organisms producing similar antagonistic substances are discussed.