Antibiotics from Xenorhabdus spp. and Photorhabdus spp. (enterobacteriaceae): (Review)

Xenorhabdus spp. and Photorhabdus spp. (Enterobacteriaceae), bacterial symbionts of the entomopathogenic nematodes Steinernema spp. and Heterorhabditis spp., respectively, are a unique, natural source of novel antibiotics. Several groups of antibiotics, such as xenorhabdins, xenorxides, xenocoumacins, indole derivatives including nematophin, genistein, stilbene derivatives, and anthraquinone derivatives in addition to bacteriocins, xenorhabdicin (phage tail-like bacteriocin), phages, and chitinases have been reported since the early 1980s. The antibiotics have not only shown promising activity against a variety of bacterial and fungal pathogens of medicinal and agricultural importance, including that against clinical-resistant strains of Staphylococcus aureus, but some also have shown other activities such as insecticidal, nematicidal, antiulcer, and anticancer activity. The suggested mechanisms of action of the antibiotics include inhibition of RNA and protein synthesis. These naturally occurring antibiotics provide useful leads in the research and development of drugs and agrochemicals. This review summarizes the chemistry and biology of these antibiotics with emphasis on the authors' work. ©1999 Kluwer Academic/Plenum Publishers.