Resistance drives antibacterial drug development.

New resistance challenges continue to evolve and spread worldwide. In an otherwise mature field, antibacterial drug development is primarily driven by resistance trends with a focus on development of new analogs of known scaffolds to strengthen them against class-specific resistance mechanisms. Currently new analogs of cephalosporins (with or without beta-lactamase inhibitors), oxazolidinones, glycopeptides, quinolones, aminoglycosides, tetracyclines, and ketolides are in clinical studies. While showing some benefit, these new analogs only partially address the clinical crisis of multidrug-resistant pathogens; this is especially the case for Gram-negative bacteria. The medical community faces grim reality-general solutions to the treatment of rapidly spreading multidrug-resistant bacteria are neither on the horizon nor anticipated.