THE LAST decade witnessed the golden age in the isolation, purification, and manufacture of antibiotic drugs. A wide variety of bacterial, rickettsial, and some viral diseases can now be selectively treated and cured with these antimicrobial agents. While the advantage gained by the clinician is great, there are new problems to confront him. Among these are the superinfections caused by secondary organisms resistant to the antibiotic drug currently employed in treating a primary sensitive pathogen.
The disturbances of the usual bacterial ecology induced by the administration of antibiotics have been described.1 Alterations of this kind have been noted in the mouth, throat, upper respiratory tract, intestinal canal, vagina, and perhaps in the skin. While the usual microbial population maintains a delicate balance between the various types, antibiotic therapy favors the multiplication of certain members of the bacterial population. Therapy directed toward infections caused by Grampositive bacteria may allow or