Development of antimicrobial agents in the era of new and reemerging infectious diseases and increasing antibiotic resistance.

During the past 2 decades, new infectious diseases have appeared and old ones previously thought to be controlled have reemerged. New and reemerging infectious agents will continue to pose serious threats well into the 21st century. The prediction that the threat of infectious disease may not diminish is supported by evidence that infectious agents cause many chronic diseases and cancer of previous unknown etiology. Moreover, the utility of existing antimicrobial agents is rapidly eroding, tipping the balance in favor of multidrug-resistant pathogens, and there appear to be few, if any, new classes of drugs currently in clinical development. The need for research directed toward development of new antibiotics has never been greater. Advances in research technologies and microbial genome sequencing in the past decade have led to identification of a large number of new targets. Functional genomics and integrative biology should validate these targets and provide the best opportunity for developing effective new therapies, improved diagnostic techniques, and better tools to understand host-pathogen interactions.