The antibiotic resistance bacteria known as carbapenem-resistant Enterobacteriaceae (CREs) are becoming a greater health hazard. According to the CDC, Klebsiella species and Escherichia coli (E. coli) are examples of Enterobacteriaceae, a normal part of the human gut bacteria, that can become carbapenem-resistant. The journal Nature has a fantastic piece on CREs, including a quote from Flemming regarding the need to guard against using antibiotics too often. CREs cause bladder, lung and blood infections that can spiral into life-threatening septic shock. They evade the action of almost all antibiotics — including the carbapenems, which are considered drugs of last resort — and they kill up to half of all patients who contract them. In the United States, these bacteria have been found in 4% of all hospitals and 18% of those that offer long-term critical care.