KPC (blaKPC) and NDM (blaNDM) Surveillance, PCR
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The Centers for Disease Control and Prevention recommends active surveillance to detect unrecognized colonized patients who may be a potential source for carbapenem-resistant (drug-resistant) Enterobacteriaceae (CRE) transmission. Such surveillance testing may be focused in certain high-risk settings or patient groups (eg, ICUs, long-term acute care, patients transferred from areas or facilities with high CRE prevalence) or by infection control to investigate an outbreak. Nonsusceptibility to carbapenems in gram-negative bacilli by means of the enzyme KPC (Klebsiella pneumoniae carbapenemase) or NDM (New Dehli metallo-beta-lactamase) is becoming more common. The genes blaKPC and blaNDM encode KPC and NDM enzyme production, respectively. PCR is a sensitive, specific, and rapid means identifying patients colonized by CRE harboring blaKPC or blaNDM.
Identifying carriers of carbapenem-resistant Enterobactericeae harboring KPC (Klebsiella pneumoniae carbapenemase) or NDM (New Dehli metallo-beta-lactamase) genes
This PCR detects and differentiates blaKPC and blaNDM in surveillance specimens (perirectal/rectal swabs or stool). A positive KPC (Klebsiella pneumoniae carbapenemase) and/or NDM (New Dehli metallo-beta-lactamase) PCR indicates that the patient is colonized by a Gram-negative bacillus (or Gram-negative bacilli) harboring a carbapenemase gene, blaKPC and/or blaNDM, respectively.
A negative result indicates the absence of detectable DNA; however, false-negative results may occur due to inhibition of PCR, sequence variability underlying primers and probes, or the presence of the blaKPC or blaNDM genes in quantities less than the limit of detection of the assay.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This assay should be used for surveillance testing on perirectal/rectal swabs or stool specimens. Request KPNRP / KPC (blaKPC) and NDM (blaNDM) in Gram-Negative Bacilli, Molecular Detection, PCR if testing isolates from culture.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Lolans K, Calvert K, Won S, et al: Direct ertapenem disk screening method for identification of KPC-producing Klebsiella pneumoniae and Escherichia coli in surveillance swab specimens J Clin Microbiol 2010;48:836-841
2. Cunningham SA, Noorie T, Meunier D, et al: Rapid and simultaneous detection of genes encoding Klebsiella pneumoniae carbapenemase (blaKPC) and New Delhi metallo-beta-lactamase (blaNDM) in Gram-negative bacilli. J Clin Microbiol 2013;51:66-69
3. New carbapenem-resistant Enterobacteriaceae warrant additional action by healthcare providers. Centers for Disease Control and Prevention Health Alert Network, February 14, 2013
4. Vasoo S, Cunningham SA, Kohner PC, et al: Comparison of a direct and broth-enriched PCR, HardyCHROM ESBL and the CDC method for detection of Klebsiella pneumoniae carbapenemase carriage in surveillance rectal swabs. Abstracts of the Ninth International Symposium on Antimicrobial Agents and Resistance, Kuala Lumpur, Malaysia, March 13-15, 2013