Infection in vitro of the human pulmonary macrophage with Staphylococcus aureus (bacteriologic and ultrastructural observations).

Alveolar macrophages from exeresis fragments taken from patients operated for pulmonary cancer were infected in vitro with Staphylococcus aureus. Part of the investigation was carried out in the presence of an antibiotic (pyopen) introduced in the culture medium. Bacteriologic seeding from an extracellular medium and from lyzed cells showed a greater intracellular multiplication rate. In the presence of pyopen there was a decrease in the number of germs due to the inhibition of multiplication. Electron microscopy revealed reduced phagolysosomal fusion, aspects of bacterial multiplication and the coexistence of intact bacteria and bacteria presenting structural alterations. The results suggest the importance of cellular parasitism in the chronic evolution of infectious bronchopulmonary processes.