Vancomycin Resistance Plasmid in Enterococcus faecalis That Encodes Sensitivity to a Sex Pheromone Also Produced by Staphylococcus aureus

Plasmid-free (recipient) strains of Enterococcus faecalis secrete a number of peptide sex pheromones that act as mating (conjugation) signals to donor bacteria harboring certain conjugative plasmids. (See reference 4 for a recent review.) Upon acquisition of such a plasmid, the related pheromone production is shut down or masked; however, other peptides that act as pheromones specific for different families of plasmids continue to be secreted. One enterococcal sex pheromone, cAM373, has been of particular interest because it is also produced by essentially all strains of Staphylococcus aureus (5). Insofar as vancomycin-resistant enterococci have become a serious clinical problem in recent years due to horizontal gene transfer (1, 3, 9-13, 15, 17), such a peptide might contribute to staphylococcal acquisition of this resistance.