Effect of Experimental Dermatophyte Infection on Cutaneous Flora

The cutaneous aerobic bacterial flora was monitored during the course of experimental dermatophyte (ringworm) infections on the forearms of 9 volunteers. Micrococcaceae were identified by the new Baird-Parker classification with the aid of a replica-plating technique. There were significant differences in total populations but not in kinds of flora compared with control (opposite) forearms. The proportion of penicillin-resistant microorganisms, however, increased during the infection, to a degree which varied as to individual. All coccal groups were affected; resistant flora diminished when the fungus was no longer detected. Staphylococci were more frequently isolated than micrococci on infected areas, but Staphylococcus aureus was not found. Trends toward hierarchies in persistance and quantities were observed among the flora, with Staphylococcus subgroups II and IV dominating the infected sites. On both areas almost all diphtheroids were nonfluorescent, lipophilic, and lipolytic. One subject consistently carried Bacillus firmus; another's normal microbiota contained Alcaligenes faecalis