Enhancement of Resistance in Mice to Staphylococcal Infection by Preliminary Treatment with a Staphylococcal Extract.

Abstract

An extract from the supernate of an epidemic strain of Staphylococcus which was not an endotoxin was injected intra-abdominally in mice. Twenty hours later the systemic resistance of these mice was significantly enhanced to lethal infections with homologous and heterologous strains of staphylococci and a toxogenic strain of Escherichia coli. This effect was demonstrable in sucking, young and old mice. However, selection of the proper dilution of challenging organisms was critical. If too large a challenge was given the protective effect was obscured. When only the highest dilution of organisms which killed more than 50% of the controls was studied highly significant protection was observed with P = <.001. We have not been able to demonstrate specific antibodies in mice given the extract and its mode of action is unknown.