[The effect of magnesium on the formation of toxic shock syndrome toxin 1 (TSST-1) by Staphylococcus aureus].

Abstract

The influence of magnesium on the production of toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus was examined. As media we used: Standard-I-Nutrient Broth, Todd Hewitt Broth, Mueller-Hinton Broth, Isosensitest Broth and a chemically defined liquid medium. The magnesium content of these media was determined using flame photometry and was subsequently changed using magnesium sulfate to the magnesium concentrations as shown in table 1. In each of these media the TSST-1 positive S. aureus strains MN8 and T 40 were grown at 37 degrees C, 18 h, vigorously shaken. Then the colony forming units (cfu) were determined. Toxin assays were performed by immunodiffusion after concentrating the culture fluids 100-fold using ethanol precipitation. Concentrations of toxin per milliliter were determined by comparison with standard toxin preparations using hyperimmune-TSST-1 antisera as described. The cfu and the amount of TSST-1 produced are shown in table 1. No link could be demonstrated between TSST-1 production and magnesium concentration of the media used. Our results are in agreement with the ones published by Schlievert and disagree with the results from Mills.