Effect of magnesium on in vitro production of toxic shock syndrome toxin 1.

Batch and chemostat culture of Staphylococcus aureus strain S411 was conducted in an investigation of the role of Mg++ in the control of production of toxic shock syndrome toxin 1 (TSST-1). Under both growth conditions, Mg++ influenced bacterial growth, and TSST-1 production was correlated with bacterial growth. The specific activity of TSST-1 (ng/mg yield, ng/mg total protein) increased with increasing concentrations of Mg++ and was maximal at physiologic levels of Mg++. No production of TSST-1 was observed under anaerobic conditions. In chemostat cultures in which valine nutrient limitation was used with various levels of tryptophan in the chemically defined medium, tryptophan concentration controlled the production of TSST-1 by strain S411, regardless of the concentration of Mg++.