Resistance of Streptococcus pneumoniae to Hypothiocyanous Acid Generated by Host Peroxidases.

Streptococcus pneumoniae is a serious human respiratory pathogen. It generates hydrogen peroxide (HO) as part of its normal metabolism, yet it lacks enzymes that remove this oxidant. Here we show that lactoperoxidase and myeloperoxidase, two host enzymes present in the respiratory tract, convert bacterial HO into HOSCN that S.

Antimicrobial Activity of Neutrophils Against Mycobacteria.

The mycobacterium genus contains a broad range of species, including the human pathogens and . These bacteria are best known for their residence inside host cells. Neutrophils are frequently observed at sites of mycobacterial infection, but their role in clearance is not well understood.

Neutrophil NET Formation with Microbial Stimuli Requires Late Stage NADPH Oxidase Activity.

Neutrophils respond to a range of stimuli by releasing extracellular traps (NETs), a mesh consisting of chromatin plus granule and cytoplasmic proteins. We have investigated NET release in response to phorbol myristate acetate (PMA), (PAO1), and , and the involvement of NADPH oxidase (NOX2) and myeloperoxidase (MPO) activities. An oxidative mechanism was involved with each stimulus, and the NOX2 inhibitor diphenylene iodonium (DPI) gave almost total inhibition.