Antimicrobial resistance is recognized as one of the greatest threats to human health worldwide [1]. Drugresistant infections take a staggering toll in the United States (US) and across the globe. Just one organism, methicillin-resistant Staphylococcus aureus (MRSA), kills more Americans every year (19,000) than emphysema, HIV/AIDS, Parkinson's disease, and homicide combined [2]. Almost 2 million Americans per year develop hospital-acquired infections (HAIs), resulting in 99,000 deaths [3], the vast majority of which are due to antibacterial (antibiotic)-resistant pathogens. Indeed, two common HAIs alone (sepsis and pneumonia) killed nearly 50,000 Americans and cost the US health care system more than $8 billion in 2006 [4]. In a recent survey, approximately half of patients in more than 1,000 intensive care units in 75 countries suffered from an infection, and infected patients had twice the risk of dying in the hospital as uninfected patients [5]. Based on studies of the costs of infections caused by antibiotic-resistant pathogens versus