Stimulation of microbial autolytic system by tryptic casein hydrolysate

Antimicrobial activity of a tryptic casein hydrolysate (TCH), its mode of antimicrobial action and its efficacy in treatment using a newborn calf colibacillosis model are described. The antimicrobial activity of TCH activated the autolytic system of the microbial cell and was expressed mathematically as the autolysis activation index. TCH stimulated the autolytic enzyme system of the 19 bacterial and five fungal strains tested. The autolysis activation index for naturally-autolyzing microorganisms was 1.45-22.0. Autolysis in three bacterial and one fungal strain that did not lyse in the absence of TCH was increased in its presence by 3.9-56.7% showing activation of latent autolysis. The in vivo trials on 800 newborn calves revealed 93.0% therapeutic and 93.5% prophylactic efficacy for TCH. These levels were similar to the 95.0 and 95.5% attained when Fermosorb, an authorized antimicrobial drug, was used.