Oxidation of bacillithiol during killing of Staphylococcus aureus USA300 inside neutrophil phagosomes.

Targeting immune evasion tactics of pathogenic bacteria may hold the key to treating recalcitrant bacterial infections. Staphylococcus aureus produces bacillithiol (BSH), its major low-molecular-weight thiol, which is thought to protect this opportunistic human pathogen against the bombardment of oxidants inside neutrophil phagosomes. Here, we show that BSH was oxidized when human neutrophils phagocytosed S.

Evaluating the bactericidal action of hypochlorous acid in culture media.

The bactericidal activity of the physiological oxidant hypochlorous acid (HOCl) is commonly studied in a variety of laboratory media. Reactive with numerous targets, HOCl will rapidly lose its toxicity via reduction or be converted to chloramines and other less toxic species. The objective of this study was to test the influence of various media, temperature and reaction time on the toxicity of HOCl.

Analysis of Neutrophil Bactericidal Activity.

This chapter describes three methods for measuring the bactericidal activity of neutrophils. All utilize colony counting techniques to quantify viable bacteria. A simple "one-step" protocol provides a composite measure of phagocytosis and killing, while a "two-step" protocol that separates extracellular and intracellular bacteria allows calculation of rate constants for both of these processes.