OK, this may really be the stuff of nightmares

January 12th, 2015

I have been reluctant to embrace the somewhat melodramatic moniker of “nightmare bacteria” for emerging carbapenem-resistant Enterobacteriaceae (CRE), which includes Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-β-lactamase (NDM).

Then I found out what was frozen in a lab in New Jersey.

Medical researchers have combined a KPC strain now common in much of the U.S. with a highly virulent Klebsiella pneumoniae isolate from Asia, conferring the multidrug resistance of the former and the killing power of the latter into a new microorganism worthy of nightmare: Hyper-virulent KPC.

“Most of the KPC strains, especially in the United States, are not virulent,” says researcher Tom Chiang, MD, an assistant professor at Rutgers and infectious disease physician at the VA New Jersey Health Care System in East Orange. “In Asia there are Klebsiella pneumoniae that are not carbapenem resistant but they are hyper-virulent. They cause invasive disease like endocarditis, liver abscesses and so forth. A lot of people don’t realize this, but once KPC comes into these hyper-virulent strains we are in for treat. We will have a pan-resistant Kleb pneumo that is also hyper-virulent. So far it has not been hyper-virulent in the United States, and the mortality for bacteremia is about 40%. So if the hyper-virulent strains obtain this KPC we are in a big trouble.”

The research by Chiang and colleagues has been submitted for publication and was presented recently in San Francisco at IDWeek.(1)

For more on this story see the February 2014 issue of Hospital Infection Control & Prevention.

Reference

1. Koper C, Eng R, Chiang T, et al. KPC Conjugation into Virulent Klebsiella pneumoniae. Session: 110. Antimicrobials: Resistance Mechanisms. IDWeek 2013. San Francisco, CA; Oct. 2-6.