DURING the past several years it has become apparent that there are an increasing number of staphylococci which are resistant to the concentrations of penicillin usually obtained in patients.1 It also seemed likely that a similar change was taking place with respect to the sensitiveness of staphylococci to the action of aureomycin, oxytetracycline (Terramycin), and Chloramphenical.2 The increased resistance of these organisms observed among patients may occur by either or both of the following mechanics: 1. Strains sensitive to the antibiotic and carried by a patient at the time the antibiotic is administered may become more resistant because of exposure to the drug, 2. Strains which are resistant to the antibiotic at the time of its introduction or those which subsequently become resistant may spread to other persons (including some who are not receiving antibiotic therapy). Several studies3 have shown that hospital personnel are important in the