Development of antibiotic resistance by staphylococcus aureus in a single patient. Confirmation by phage typing,...

A patient is described who had colonization and infection with strains of Staphylococcus aureus increasingly resistant to multiple antibiotics while receiving several courses of broad-spectrum antibiotics. S. aureus strains with different phage types, antibiograms, and plasmid profiles were isolated from different sites at the same time. After the patient was transferred to an intermediate-care service where he received only supportive care and no further antibiotics, culture samples from areas previously colonized or infected (sputum, anterior nares, perineal region, rectum) showed no S. aureus. This patient graphically demonstrates that antibiotics may create an environment allowing the overgrowth of resistant organisms and that withdrawal of this selection pressure may allow more sensitive organisms to recolonize.