The action of cells from patients with chronic granulomatous disease on Staphylococcus aureus

Contrary to current opinion, neutrophil leucocytes from patients with the inherited immunodeficiency syndrome chronic granulomatous disease (CGD) killed 80% of ingested Staphylococcus aureus. Bacterial killing was not impaired by increasing the ratio of bacteria to cells from 1:1 to 10:1. The organisms that survived within the patients' cells did not themselves appear to constitute an unduly resistant subpopulation because they were killed when exposed to fresh cells, and no growth phase of a synchronous culture was found to be particularly resistant. The pH within the phagocytic vacuoles of CGD neutrophils and monocytes is abnormally low and methylamine, which has been shown to normalise this vacuolar pH, improved killing. Clumped bacteria appeared to be more resistant to killing than dispersed ones, suggesting that organisms near the centre of a clump might be protected from the toxicity of the compromised killing systems in cells of these patients.