Author – Brandi Limbago, PhD
CDC’s Division of Healthcare Quality Promotion
You’ve likely seen the news over the last couple of weeks warning people about “The [so-called] New Superbug NDM-1,” a newly discovered gene that makes bacteria resistant to last-resort antibiotics called beta-lactams or carbapenems. NDM stands for New Delhi Metallo-beta-lactamase, and in this case the NDM gene rendered antibiotics useless in three cases of infection with carbapenem-resistant Enterobacteriaceae (CRE). CDC discovered NDM-1 in the United States this year and reported it through the MMWR in June. Is it concerning? Absolutely; and we are working closely with healthcare providers and health departments to stop transmission of these bacteria.
That said, I’d like to point out that the story shouldn’t be solely about these bacteria being new or imported from other countries; the story should be about the whole group of CRE and untreatable infections they cause. In reality, these are not the first CRE cases we’ve seen in the United States. Not even close. NDM-1 is actually just one type of CRE and represents a larger antibiotic resistance issue that we already have, right now, in this country. CDC has been working with partners to prevent a type of CRE known as KPCs (carbapenemase-producing Klebsiella pneumonia). The KPC gene also makes Enterobacteriaceae bacteria resistant to beta-lactam/carbapenem antibiotics, just in a different way than NDM-1. KPCs have been reported in about 35 states and are associated with high mortality – 40 percent in one report. It may be in the other 15 states as well, but has not been reported to CDC. So, let’s not wait for NDM-1 in order to take action.