The challenge of multidrug resistance: actual strategies in the development of novel antibacterials.

Bacterial resistance against established antibiotics is becoming an increasingly important global healthcare problem. Despite enormous efforts, the number of therapeutically useful compounds that emerge from chemical derivatisation programs, which aim at circumventing mechanisms of resistance, is continuously decreasing and no truly novel class of compound has been introduced into therapy for nearly four decades. Hopes are now set on a thorough elucidation of bacterial cell functions to identify new bacterial target sites, and on the development of novel compounds with alternative modes of action. The pursuit of these strategies is rendered possible by employment of biotechnologically based methods such as in vivo modification of biosynthetic routes in antibiotic-producing organisms, large-scale screening assays with isolated bacterial targets, the molecular profiling of bacterial genomes and proteomes, and the development and clinical use of biochips as diagnostic tools for rapid identification and characterization of pathogenic strains. As one of the most promising class of compounds known to date with unique modes of action that escape most known mechanisms of resistance, peptic agents have recently came under the focus of anti-infective research, just as extracellular signalling molecules (autoinducer) have emerged as new bacterial target sites.