Mice lacking reduced nicotinamide adenine dinucleotide phosphate oxidase activity show increased susceptibility to early infection with Listeria monocytogenes.

Mice lacking the gp91 protein of reduced nicotinamide adenine dinucleotide phosphate oxidase showed heightened susceptibility to Listeria infection. The enhanced susceptibility was noted 2 days after infection, the usual peak time of the neutrophil-dependent lesion in the liver. Infected gp91phox -/- mice had an increase of approximately 30-fold in Listeria in the liver and an increase in the number of microabscesses. The study of the gp91phox mice underscores the early role of the neutrophil and of an oxidative burst in this infection with an intracellular pathogen. These results contrast with others showing that the late macrophage-dependent stage of the infection is dependent on nitric oxide.