Cloning and expression of streptococcal pyrogenic exotoxin A and staphylococcal toxic shock syndrome toxin-1 in Bacillus subtilis

The genes encoding streptococcal pyrogenic exotoxin type A (SPE A) and staphylococcal toxic shock syndrome toxin-1 (TSST-1) were stably cloned and expressed in Bacillus subtilis. In the non-pathogenic Bacillus background, the recombinant speA clone expressed 32-fold more SPE A than the native streptococcus, and similarly, the recombinant plasmid harboring tst expressed 4-fold more TSST-1 in Bacillus than in the native Staphylococcus aureus. The Bacillus-derived products were secreted into the culture fluid, were resistant to proteolytic degradation and their biological activites mimicked native preparations.