(August 2004) In the last century, nothing has made a bigger impact on human health than antimicrobial chemotherapy [1]. After 20 years of clinical use, antibiotics have increased the average human life expectancy by ten years while in comparison, curing cancer would only only extend life expectancy by two years [1]. From 1900 to 1990, the average life expectancy of citizens of the U.S. increased a staggering 29 years. In fact, in most of developed countries, mortality due to infectious disease has largely been replaced with mortality due to chronic illnesses such as heart disease, cancer and strokes. Although the…