Growth of Staphylococcus aureus and synthesis of toxic shock syndrome toxin 1 in different in vitro systems

Various complex and synthetic bacterial growth media have been used to study the growth of Staphylococcus aureus and the production of toxic shock syndrome toxin 1 (TSST-1) under certain in vitro culture conditions. Because of the biochemical and nutritional differences between these media and human menses, a program was designed to determine the growth and metabolism of S. aureus under conditions that more closely approximate in vivo conditions. Human menses, an artificial menses developed to match human menses, whole human blood, and complex bacterial culture media (with and without added whole human blood) were tested for the ability to support the growth of S. aureus and the production of TSST-1 in vitro. In addition, the impact of other organisms, commonly isolated from the human vagina, on the growth of S. aureus and the production of TSST-1 was evaluated. Results show that the environmental conditions provided by human menses are more closely approximated by the artificial menses and that neither commercial bacterial growth media alone nor complex media plus 25% or 50% human blood provide a menses-like environment for the growth of S. aureus and the production of TSST-1. Furthermore, the addition of a second organism to the S. aureus culture resulted in significant suppression of TSST-1 production, even when in vitro conditions were optimized for the production of TSST-1.