Detection of Pseudomonas aeruginosa producing metallo-β-lactamase VIM-2 in a central hospital from Portugal

Excerpt

Pseudomonas aeruginosa remains one of the most important pathogens in the nosocomial setting [1]. P. aeruginosa exhibits intrinsic resistance to several antimicrobial agents. The antipseudomonal β-lactams represent a major weapon against Pseudomonas infections, either for monotherapy or for combination therapy, for which β-lactams almost invariably represent one of the components. Therefore, resistance to these agents constitutes a major challenge for anti-Pseudomonas chemotherapy. Several mechanisms can contribute to β-lactam resistance in P. aeruginosa, including β-lactamase production, outer membrane impermeability and active efflux mediated by RND-type efflux systems [1]. During the last decade, the metallo-β-lactamases (MBLs) have emerged as new threatening mechanisms of broad-spectrum β-lactam resistance in P. aeruginosa. In fact, these enzymes can efficiently degrade virtually all antipseudomonal β-lactams (except aztreonam), while they are not susceptible to therapeutic β-lactamases inhibitors [2]. Based on amino acid sequence homology, these MBLs have been classified into four major types: IMP, VIM, SPM and GIM. Clinical isolates harbouring the MBLs IMP and VIM have been increasingly reported worldwide, mostly in European and Asian countries [2]. This increase in occurrence, types and rate of dissemination of MBLs makes early detection very critical. The benefits of such treatment include the timely implementation of strict infection control practices, as well as clinical guidance. …