Carbapenem-resistant enterobacteriaceae (CRE) are gram-negative bacteria that are nearly resistant to the carbapenem class of antibiotics, considered the "drug of last resort" for such infections. Enterobacteriaceae are common commensals and infectious agents. Experts fear CRE as the new "superbug".[1] The bacteria can kill up to half of patients who get bloodstream infections.[2] Tom Frieden, head of the Centers for Disease Control has referred to CRE as "nightmare bacteria".[2][3]