Combination Therapy for Carbapenem-resistant Gram-negative Bacteria

Alexandre P Zavascki; Jurgen B Bulitta; Cornelia B Landersdorfer

Disclosures

Expert Rev Anti Infect Ther. 2013;11(12):1333-1353. 

In This Article

Carbapenem-resistance, Multidrug-resistance, Extended Drug-resistance & Pan-drug-resistance

Carbapenem resistance in P. aeruginosa, A. baumannii and Enterobacteriaceae is almost always associated with resistance to several other classes of antibiotics, because carbapenemase-encoding genes are located on mobile genetic elements that usually carry genes responsible for resistance to other antibiotics.[2,8] Recently, a group of experts proposed a consensus on the definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria.[22] Briefly, a MDR GNB is an isolate that is non-susceptible to at least one agent in at least three antimicrobial categories, which are potentially active against the respective GNB. An isolate is XDR, if it is non-susceptible to at least one agent in all but two or fewer antimicrobial categories, which are potentially active against the respective GNB. Finally, PDR is defined as non-susceptibility to all agents in all antimicrobial categories for this isolate.[22] Although the definitions for MDR and XDR do not require resistance to carbapenems, the CR phenotype is very common for MDR and particularly for XDR isolates. These and PDR GNB are the major clinical challenges for antimicrobial therapy. In the remaining sections of this review, we refer to CR GNB as isolates with XDR and, eventually, PDR phenotype.

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