Toxicity of staphylococcal toxic shock syndrome toxin 1 in rabbits

Strains of Staphylococcus aureus associated with toxic shock syndrome produce toxic shock syndrome toxin 1 (TSST 1), which is lethal to conventional rabbits and acts synergistically with gram-negative lipopolysaccharide. The lethal effect of TSST 1 was examined in specific-pathogen-free rabbits on the basis that these rabbits, being less colonized by gram-negative bacteria, would be less susceptible than conventional animals. Although there was no significant difference in mortality between specific-pathogen-free and conventional rabbits in response to 100 micrograms of TSST 1, there was a difference in response between Dutch belted rabbits and New Zealand white rabbits. Both specific-pathogen-free and conventional New Zealand white rabbits were more susceptible to TSST 1 than the Dutch belted strain. Pretreatment of conventional New Zealand white rabbits with polymyxin B neutralized the lethal effect of TSST 1.