Chemical signals in gram-positive bacteria: the sex-pheromone system in Enterococcus faecalis.

This review summarizes relevant aspects of the sex-pheromone system of Enterococcus faecalis, a novel form of bacterial conjugation that plays a major role in the horizontal dissemination of genes. The process is initiated by a chemical signal, the sex pheromones, and includes several stages of interaction between the donor cell and the recipient cell. Most work in this area has focused on three plasmids, the haemolysin-bacteriocin plasmid pADI, the bacteriocin plasmid pPD1 and the Tecr (Tn125) plasmid pCF10. These plasmids share many molecular and genetic features but exhibit some interesting differences at the regulatory level. Preliminary studies suggest that many of the major components of this system may also play a role in host-parasite interactions involving enterococci.