Effect of toxic shock syndrome toxin 1 on chicken embryos.

Staphylococcus aureus strains associated with toxic shock syndrome produce toxic shock syndrome toxin 1 (TSST1). This toxin has a variety of biological effects, including enhanced lethality in rabbits in the presence of sublethal amounts of lipopolysaccharide (LPS). Because chicken embryos are highly susceptible to LPS, the synergistic effect of TSST1 and LPS was examined in this system. Although TSST1 per se had no effect on chicken embryos, it potentiated the lethal effect of LPS. The 50% lethal dose of LPS was greatly reduced in the presence of up to 10 micrograms of TSST1 per ml. However, at high doses of TSST1 (greater than 100 micrograms/ml), no enhanced lethality was observed. The lowest dose of TSST1 tested which potentiated lethality was 10 ng/ml.