New antibiotic-resistant organism elicits CDC recommendations

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Infection control

New antibiotic-resistant organism elicits CDC recommendations

After reading this article, you will be able to:

  • List the CDC’s recommendations for prevention of carbapenem-resistant Klebsiella pneumoniae

Although much of the focus of multidrug-resistant organisms has been on MRSA, a relatively new and potentially more dangerous infectious disease has begun to draw attention from infection control regulators.

Carbapenem-resistant or carbapenemase-producing Enterobacteriaceae (CRE) have recently emerged as the most common gram-negative bacteria and a challenge for healthcare providers worldwide.

More specifically, according to the March 20 Morbidity and Mortality Weekly Report (MMWR), carbapenem-resistant Klebsiella pneumoniae (CRKP) is a species of CRE associated with:

  • High morbidity and mortality
  • Prolonged length of stay
  • Increased cost

Physicians in the United States have come across this bacterium more frequently, particularly in New York City and New Jersey.

“I think it’s a new issue,” says Arjun Srinivasan, MD, an epidemiologist in the Division of Healthcare Quality Promotion at the Centers for Disease Control and Prevention (CDC). “These organisms are not widely encountered. We’ve seen them in isolated examples in at least half the states in the country, but they are not present everywhere and they are not ubiquitous things like C. diff and MRSA. I think, however, there is a rapidly growing awareness of the challenges that these organisms pose both from an infection control standpoint and from a clinical standpoint.”

According to the March 20 MMWR, CRKP has been rapidly growing since 2000. The CDC indicated that 8% of all Klebsiella isolates were CRKP, compared with fewer than 1% in 2000, according to the report.

The emergence of this infection has prompted officials at the CDC’s Healthcare Infection Control Practices Advisory Committee to release a new set of guidelines to prevent CRKP.


For prevention of this potentially deadly organism, the CDC has recommended an aggressive infection control strategy using contact precautions and implementing Clinical and Laboratory Standards Institute (CLSI) guidelines for detection of CRKP (see the sidebar at right).

Clinical microbiology laboratories should follow CLSI guidelines for susceptibility testing and for detecting carbapenemase production (i.e., the Modified Hodge Test).

Surveillance of CRKP will be particularly important to determine whether the bacteria were present at the facility, and if so, where they can be traced. Doing so will allow organizations to pinpoint the source and implement prevention measures, such as additional screening for CRKP. In this case, active surveillance is much more important in the prevention of the bacteria, since much less is known about controlling them, Srinivasan says.

Early implementation of these precautions will ensure that CRKP doesn’t become a widespread infection like MRSA, Srinivasan says. Allowing the infection to grow and build a stronger resistance will only lead to more problems in the future.

“I think there is a potential opportunity here to keep this contained before it becomes truly widespread and an endemic,” Srinivasan says. “That’s really what we are emphasizing, the need to act early and aggressively to control these carbapenem-resistant Enterobacteriaceae.”


Adapted from Briefings on Infection Control, June 2009, HCPro, Inc.

Recommendations for CRKP

Below are the steps suggested by the Clinical and Laboratory Standards Institute to detect carbapenem-resistant Klebsiella pneumoniae (CRKP) in an acute care facility in areas where carbapenem-resistant or carbapenemase-producing Enterobacteriaceae (CRE) are not currently prevalent:

  • Review clinical culture results in the microbiology lab for the previous six to 12 months to determine whether previously unrecognizable strains are present
  • If previously unrecognized CRE are found, a point prevalence survey should be performed to look for CRE in high-risk units
  • If the point prevalence survey reveals CRKP or unrecognized forms of CRE, the facility should conduct active surveillance testing for patients with epidemiologic links to people with a CRE infection (e.g., nearby patients and healthcare personnel)
  • In areas where CRE are endemic, the procedures above might not be sufficient to prevent transmission, in which case facilities should consider alternative strategies described in the Centers for Disease Control and Prevention’s Management of Multidrug-Resistant Organisms in Healthcare Settings, 2006 (

Source: Morbidity and Mortality Weekly Report, March 20, 2009, Vol. 58, No. 10 (