Carbapenem is a potent β-lactam antimicrobial drug used to kill gram-negative rod bacteria such as Enterobacteriaceae. Although rare, some Enterobacteriaceae have picked up pieces of genetic material that allow them to make carbapenemases which break down carbapenems and make the bacteria resistant to these antibiotics. This is especially alarming given that carbapenems have become the antibiotics of last resort in hospitals when conventional antibiotics do not work.
Enterobacteriaceae are a large family of gram-negative rods that include species that are harmless microflora. However, some of these bacteria, such as Salmonella, E. coli ,Klebsiella and Yersinia pestis can cause severe human infections and death. Many of these infections are associated with the use of medical equipment and hospital equipment used in western style medicine. CRE are mostly associated with Klebsiella pneumonia or E. coli infections in hospitals and community-acquired infections are relatively rare.
CRE are classified according to the type of carbapenemase-resistance gene they have. There are a few particular CRE strains that are causing concern because, although they originated in Asia, are making their way to Canada and the U.S.