The Staphylococcal Interference Effect

Abstract

SUMMARY.An injection of bacterial supernatant from pathogenic or non-pathogenic staphylococci produces in mice a high degree of early and transient protection against staphylococcal infection and a low degree of protection against infection by other organisms. Similar results were obtained with purified fractions of the staphylococcal supernatant. A Pseudomonas preparation, however, gave an equally high degree of protection against staphylococcal and Bacillus friedlander infections.Mice protected with staphylococcal supernatant, when given an injection of zymosan 24 hours before being subsequently infected, showed a marked decrease of resistance to staphylococcal infection and an increase of resistance to infection by B. friedlander. Similar treatment with zymosan had little effect on the degree of protection in mice immunised with Pseudomonas culture supernatant. Zymosan alone, given under the conditions of the above test, had no effect on the susceptibility of the mice to staphylococcal or B. friedUmder infection.