Bacterial Interference

IT HAS been shown that colonization by one strain ofStaphylococcus aureusof the nasal mucosa of adults1-4and the nasal mucosa and umbilicus of infants5-11interferes with subsequent colonization at those sites by other strains of coagulase positive staphylococcus. This phenomenon, called bacterial interference, has been successfully utilized to curtail epidemics ofS aureusin newborn nurseries. A similar protective effect has been demonstrated in adults. In two separate controlled studies, carriers ofS aureuswho were deliberately colonized following local nasal and systemic antibiotic therapy were protected from recolonization when directly challenged by a second strain ofS aureus.1,2Cessation of recurrent bouts of furunculosis following recolonization was reported recently in one individual3and in one family.4 The present study demonstrates that artificial colonization with the 502A strain not only protects families against recolonization by the original resident strain ofS aureusbut