Staphylococcal bacteremia in a "Germ-free" unit.

The rate of carriage and infections due to strains of Staphylococcus aureus were evaluated in adults with acute leukemia in isolators characterized by laminar air flow and barrier isolation. Patients were randomly given antimicrobial prophylaxis with oral nonabsorbed antibiotics and a nasal antibiotic ointment. In four years S aureus was isolated from the nostrils or other sites in 36 patients. Persistent isolation was noted in 24 patients. Suppression of gut flora was associated with a higher carriage rate of S aureus. Five episodes of bacteremia due to S aureus occurred at the nadir of leukopenia induced by chemotherapy. Death occurred within five days in the three patients whose peripheral white blood cell count did not rise. Patient isolation and suppression of gut flora helped reduce infections due to Pseudomonas sp and fungi, but S aureus emerged as a life-threatening pathogen.