Historically, the discovery of the sulfa drugs in the 1930s and the subsequent development of penicillin during World War II ushered in a new era in the treatment of infectious diseases. Infections that were common causes of death and disease in the pre-antibiotic era - rheumatic fever, syphilis, cellulitis and bacterial pneumonia - became treatable, and over the next 20 years most of the classes of antibiotics that find clinical use today were discovered and changed medicine in a profound way. The availability of antibiotics enabled revolutionary medical interventions such as cancer chemotherapy, organ transplants and essentially all major invasive surgeries from joint replacements to coronary bypass. Antibiotics, though, are unique among drugs in that their use precipitates their obsolescence. Paradoxically, these cures select for organisms that can evade them, fueling an arms race between microbes, clinicians and drug discoverers. Wright BMC Biology 2010, 8:123 http://www.biomedcentral.com/1741-7007/8/12