Enterobacteriaceae Producing ESBLs in the Community: Are They a Real Threat?

Antimicrobial-resistant organisms are an emerging global health problem that will likely evolve into one of the most significant challenges facing medical practice.1 Infections with resistant organisms lead to increased patient morbidity as a result of antibiotic treatment failures. Costs incurred by prolonged hospital stays are only a small portion of the additional expenses associated with these infections. It has been estimated that microbial resistance could add $0.1 billion to $10 billion annually to health care costs in the United States.2 Moreover, once generated, resistance does not disappear quickly. This leads to dramatic increases in costs of care and infection prevention efforts and the need for more effective antimicrobial agents.3 Of most concern, however, is that the rates of the development of resistance among some organisms are challenging the ability of the pharmaceutical industry to design effective new agents.4 It is quite conceivable that in the near future, organisms will have developed resistance to all available antimicrobial agents. For Gram-negative pathogens, lactamase production remains the most important contributing factor to -lactam resistance.5 One important group of -lactamases—the extended-spectrum -lactamases (ESBLs)—is an increasingly significant cause of treatment failure. In this article, I will discuss the clinical significance and emergence of the ESBLs in the community setting.