Identification of genes encoding two-component lantibiotic production in Staphylococcus aureus C55 and other phage group II S-aureus strains and demonstration of an association with the exfoliative toxin B gene

The production of exfoliative toxin B (ET-B), but not ET-A, was shown to be specifically associated with production of a highly conserved two-componen t lantibiotic peptide system in phage group II Staphylococcus aureus. Two p reviously studied but incompletely characterized S. aureus bacteriocins, st aphylococcins C55 and BacR1, were found to be members of this lantibiotic s ystem, and considerable homology was also found with the two-component Lact ococcus lactis baeteriocin, lacticin 3147. sac alpha A and sac beta A, the structural genes of the lantibiotics staphylococcins C55 alpha and C55 beta and two putative lantibiotic processing genes, sacM1 and sacT, were locali zed together with the ET-B structural gene to a single 32-kb plasmid in str ain C55. In-eversible loss of both ET-B and two-component lantibiotic produ ction occurs during laboratory passage of ET-B-positive S. aureus strains, particularly at elevated temperatures.