Carbapenemase-producing Enterobacteriaceae: a call for action!

Since the beginning of this century, we have been observing increasingly rapid diffusion among Enterobacteriaceae of extended-spectrum b-lactamases (ESBLs), mostly of the CTX type and mostly in Escherichia coli [1]. This phenomenon has run out of control within just 10 years, and the outbreak is now internationally identified as being, in particular, a source of community-acquired infections. In this context of multiresistance, the increasing number of carbapenemase-producing Enterobacteriacae is worrying, because carbapenems represent the last line of antibiotics that are still effective for treating many enterobacterial infections [2,3]. Although the hydrolytic profile of carbapenemases (mostly KPC, OXA-48, IMP, VIM, and NDM) is somewhat variable, all of them hydrolyse at least carbapenems [4–6]. The corresponding genes may be considered as markers of multidrug resistance—or even pandrug resistance—in specific areas in the world, as they are often found together with genes conferring resistance to most b-lactams, aminoglycosides, and fluoroquinolones. All of these genes are easily transferable within Enterobacteriaceae, because they are plasmid-borne. If one considers the carbapenemase type and the host bacterial species, so far KPC, IMP and VIM seem to have been mostly identified in the main nosocomial pathogen, which is Klebsiella pneumoniae [4–6]. By contrast, in the case of carbapenemases of the NDM and OXA-48 types, both K. pneumoniae and E. coli can be regarded as sources of both nosocomial and community-acquired infections [4–6]. Identification of carbapenemase producers in Enterobacteriacae is becoming the major issue among antibiotic resistance problems worldwide, and in particular in Europe, for the following reasons: