Detoxification and Immunogenic Properties of Endotoxin-Containing Precipitate of Brucella abortus

Abstract

Endotoxin-containing precipitates (ECP) were prepared from Brucella abortus strain 19A by aqueous ether extraction followed by ethyl alcohol precipitation. Lysozyme was the most effective of several enzymes tried for detoxification of endotoxin present in the precipitate. Trypsin was shown to reduce mouse lethal toxicity but not rabbit dermal toxicity. Immuno- logical studies of ECP and enzyme-treated ECP demonstrated that lysozyme did not harm the immunogenic property of ECP, whereas heat, ribonuclease, lipase, and proteolytic enzymes had an adverse effect. Serological reactivity of ECP was increased after lysozyme treatment, whereas ribonuclease reduced serological activity.