Carbapenem-resistant Enterobacteriaceae (CRE) are regular gram-negative bacteria such as Klebsiella and E. coli that all people carry around in their bowels, with one large exception: CRE carry multiple antibiotic-resistance genes, such as NDM-1 and KPC, that make infection very hard to treat. More of these genes are being identified all the time. Organisms carrying these genes were first reported outside of Canada (e.g., the "ND" in NDM-1 stands for "New Delhi"), but we now have documented CRE outbreaks in Canada as well. Most organizations have not yet seen CRE, but it's fairly certain that all organizations will see them within the next few years.
Unfortunately, roughly one in five hospitalized patients colonized with these organisms will develop invasive infections. Gram-negatives can cause infections anywhere in the body, but are particularly known for causing urinary tract, bloodstream, wound, and lung infections. Generally speaking, the sicker the patient, the more likely he or she is to develop an infection with a gram-negative organism.
In the ranking of antibiotic-resistant organisms by impact, CRE are near the top of the list—not just because these organisms are highly resistant, but because they cause serious infections and spread quickly.
For information on screening and treating CRE, please refer to the tools and resources noted below.