Guinea-pig alveolar macrophage killing of Mycobacterium tuberculosis, in vitro, does not require hydrogen peroxide or hydroxyl radical.

Alveolar macrophages from the lungs of guinea-pigs that had been vaccinated, boosted and then intravenously challenged with Mycobacterium bovis BCG, killed both a hydrogen-peroxide-resistant and a hydrogen-peroxide-sensitive strain of M. tuberculosis, in vitro. Pretreatment of the alveolar macrophages, in vitro, with catalase or mannitol, agents which remove hydrogen peroxide and the hydroxyl radical, respectively, did not decrease the extent of killing of either strain. In contrast, pretreatment of alveolar macrophages with catalase, reversed the inhibition of growth of Listeria monocytogenes.