ABSTRACT
Over the past two decades, rates of antimicrobial resistance have
increased rapidly. Of the two million annual nosocomial infections in
the United States, more than 50% are caused by drug-resistant strains
of bacteria (1,2). Drug resistance has a considerable impact on patient
morbidity and mortality, and is a major economic burden for society with
yearly expenditures ranging from US$4 billion to US$30 billion (1-3).