New antimicrobial agents on the horizon.

Antibiotic resistance issues necessitate the continued discovery and development of new antibacterial agents. Efforts are ongoing in two approaches to find new compounds that are effective against antibiotic-resistant pathogens. These efforts involve modification of existing classes including fluoroquinolones, tetracyclines, aminoglycosides, and β-lactams and identification of inhibitors against previously unexploited antibacterial targets. Examples of both approaches are described here with emphasis on compounds in late pre-clinical or clinical stages of development.