Abstract:

Summary. Viable Staphylococcus aureus (strain Oxford beta lactamase negative) which had been cultivated either in the absence or presence of penicillin G (subinhibitory concentrations) were injected into the knee joint of adult rats. Tissue sections taken five days following the injections and analyzed by an electron microscope revealed the persistence of apparently intact cell walls within macrophages at the inflammatory sites. The data suggest that even under penicillin effect the macrophages were capable only of digesting the bacterial cytoplasmic constituents (plasmolysis) but failed to degrade the bacterial peptidoglycan. The possible role played by anionic polyelectrolytes, which accumulate at the inflammatory sites, in the inhibition of cell wall degradation by leukocytes in 1/it/0 and the role played by leukocyte factors in the activation of the bacterial own autolytic wall enzymes will be discussed.