Superbug: Hypervirulent KPC Created In Lab, Reported In Nature

"A frightening clinical scenario."

Feb 06, 2014, 16:12 ET from AHC Media

ATLANTA, Feb. 6, 2014 /PRNewswire/ -- Highly virulent and nearly completely resistant to antibiotics, a pathogen that occurred in nature at least once and created with shocking ease in the lab poses a "catastrophic threat" to the U.S. health care system, the lead investigator of the research tells Hospital Infection Control & Prevention.


"This conjugated strain killed [lab] mice really quickly, plus being almost pan-resistant to all antibiotics at that point," says Tom Chiang, MD, an assistant professor at Rutgers University and infectious disease physician at the VA New Jersey Health Care System in East Orange.

Chiang and colleagues combined a carbapenem-resistant Enterobacteriaceae (CRE) enzyme Klebsiella pneumoniae carbapenemase (KPC) -- which has increased dramatically in the U.S. -- with a highly virulent but drug susceptible isolate of K. pneumonia from Asia. The resulting conjugated microorganism retained the high drug resistance of the KPC and the full virulence of the Asian K. pneumoniae isolate.

A Centers for Disease Control and Prevention investigator says there are no confirmed reports in the U.S. of a hypervirulent KPC strain.

"These more virulent strains of Klebsiella are called the hypermucoviscous strains," says Alexander Kallen, MD, MPH, a medical epidemiologist and outbreak response coordinator in the CDC Division of Healthcare Quality Promotion. "We certainly haven't found this in any of the isolates that we have been sent, but that doesn't mean it can't happen or isn't happening."

Indeed, the likelihood of a conjugation occurring between the microbes in nature may increase as the hypervirulent Asian strains move into areas endemic with KPC or vice versa. Researchers have reported that the hypervirulent -- but still drug susceptible strains -- appear to be emerging out of Asia and are "now increasingly recognized in Western countries. Defining clinical features are the ability to cause serious, life-threatening community-acquired infection in younger healthy hosts, including liver abscess, pneumonia, meningitis and endophthalmitis and the ability to metastatically spread, an unusual feature for enteric Gram-negative bacilli in the non-immunocompromised. Despite infecting a healthier population, significant morbidity and mortality occurs. … If/when these strains become increasingly resistant to antimicrobials, we will be faced with a frightening clinical scenario."

Hospital Infection Control & Prevention is published monthly by AHC Media, a leading publisher of healthcare information for physicians, nurses and hospital administrators. Its titles are read monthly by more than 25,000 professionals.

Contact: Lee Landenberger, 404-262-5422,