The emergence and dissemination of carbapenem resistance among Enterobacteriaceae, especially Klebsiella pneumoniae, constitute a serious threat to public health, since carbapenems are the agents of last resort in the treatment of life-threatening infections caused by drug-resistant Enterobacteriaceae. In K. pneumoniae, carbapenem resistance was first reported a decade ago and has subsequently emerged in several countries. One particular group of transmissible plasmid-encoded carbapenemase enzymes, designated K. pneumoniae carbapenemase (KPC), confers carbapenem resistance to K. pneumoniae strains and is rapidly spreading worldwide.
In addition to KPC-producing K. pneumoniae, several different metallo-β-lactamase-producing strains have been identified. These include New Delhi metallo-β-lactamase, Verona integron-encoded metallo-β-lactamase and imipenemase metallo-β-lactamase. Finally, class D carbapenemases, including oxacillin-type carbapenemases, also occur in K. pneumoniae.
Carbapenem-resistant K. pneumoniae (CRKP) can cause several types of healthcare-associated infections, including pneumonia, bloodstream infections, wound or surgical site infections, urinary tract infections and meningitis, and is associated with high mortality rates.
Multifactorial intervention, including hand hygiene, contact precautions, patient and staff cohorting, minimizing invasive device use, promoting antimicrobial stewardship, screening, active surveillance testing and chlorhexidine bathing, may be an effective strategy for reducing the nosocomial transmission of CRKP. Moreover, the rapid notification of clinical infection whenever CRKP are identified from clinical specimens allows the timely implementation of control measures.