A CDC researcher holds up two culture plates growing bacteria in the presence of discs containing various antibiotics. The isolate on the left plate is susceptible to the antibiotics on the discs and is therefore unable to grow around the discs. The one on the right has a CRE (Carbapenem-resistant Enterobacteriaceae) that is resistant to all of the antibiotics tested and is able to grow near the disks. Experts fear CRE may be the new "superbug," as the bacteria kill up to half of patients who get bloodstream infections from them (CRE Sepsis).