Resistance to Infection With Staphylococcus Aureus

Last year Shinefield and his associates demonstrated that the presence of one strain ofStaphylococcus aureusat a particular site (nasal or umbilical) interfered with subsequent acquisition of another coagulase-positive staphylococcal strain at that site. The phenomenon of interference was utilized in four different hospital newborn services to protect infants against infection and disease caused by epidemic strains ofStaph aureus. Resistance to infection due to bacterial interference is one example of infection-immunity or premunition, a poorly understood phenomenon observed since 1919 in several experimental and natural situations by immunologists and bacteriologists.1 After the encouraging initial observations, further investigations in man and animals were undertaken in an attempt to understand the mechanism of this type of protection. Currently, two experimental models are under study. Ribble and Shinefield have shown that the infection of the allantoic cavity of fertile chicken eggs with avirulent staphylococci protects chick embryos against the lethal