Antistaphylococcic Factors in Brain Extract

Abstract

OUR colleagues, Nutini and Lynch, have shown¹ that a crude extract (prepared by freezing and thawing ox brain, centrifuging, precipitating proteins with 95 per cent ethanol, filtering and concentrating in vacuo) was very effective in the prevention and treatment of Staphylococcus aureus (Micrococcus pyogenes, var. aureus) infections in mice. In vitro, the extract was found to stimulate the growth of the organism on nutrient agar, with conversion of the orange or yellow S variety to a white P configuration^1d, and to inhibit toxin formation by the organism^1a. We wish to report investigations on the concentration and characterization of the active factors in the extract. Effectiveness of the fractions was evaluated in terms of the dose which protected mice from death by S. aureus infection, using a combined prophylactic-therapeutic procedure based upon that originally described^1a.