New agents in development for the treatment of bacterial infections.

New antibacterial agents to treat infections caused by antibiotic-susceptible and antibiotic-resistant pathogens are in various stages of clinical development. In this review are compounds with demonstrated activity against methicillin-resistant staphylococci including investigational cephalosporins, carbapenems, and a new tetracycline, as well as glycopeptides effective against vancomycin-resistant enterococci (VRE), and fluoroquinolones with improved potency against respiratory pathogens and multidrug-resistant Gram-positive bacteria. Although most recent progress has occurred in the identification of agents for Gram-positive infections, broad-spectrum carbapenems are described for the treatment of multidrug-resistant Gram-negative pathogens. Also discussed are agents with mechanisms of action other than inhibition of protein synthesis, penicillin-binding proteins, and DNA topoisomerases; among these are inhibitors of bacterial fatty acid biosynthesis, peptidoglycan synthesis, and dihydrofolate reductase.