VIM-1-producing Klebsiella pneumoniae (VPKP) is an emerging pathogen. A prospective observational study was conducted to evaluate the importance of VIM production on outcome of patients with K. pneumoniae bloodstream infections (BSIs). Consecutive patients with K. pneumoniae BSIs were identified and followed up until patient discharge or death. A total of 162 patients were included in the analysis; 67 (41.4%) were infected with VPKP, and 95 were infected with non-VPKP. Fourteen of the patients infected with VPKP were carbapenem resistant (Carb r ) (MIC > 4 g/ml), whereas none of the non-VPKP exhibited carbapenem resistance. The patients infected with a Carb r organism were more likely (odds ratio, 4.08; 95% confidence interval [CI], 1.29 to 12.85; P ‫؍‬ 0.02) to receive inappropriate empirical therapy. The all-cause 14-day mortality rates were 15.8% (15 of 95) for patients infected with VIM-negative organisms, 18.9% (10 of 53) for those infected with VIM-positive carbapenem-susceptible organisms, and 42.9% (6 of 14) for those infected with VIM-positive Carb r organisms (P ‫؍‬ 0.044). In Cox regression analysis, age (hazard ratio [HR], 1.03; 95% CI, 1.01 to 1.06; P ‫؍‬ 0.021), rapidly fatal underlying disease (HR, 2.84; 95% CI, 1.26 to 6.39; P ‫؍‬ 0.012), and carbapenem resistance (HR, 2.83; 95% CI, 1.08 to 7.41; P ‫؍‬ 0.035) were independent predictors of death. After adjustment for inappropriate empirical or definitive therapy, the effect of carbapenem resistance on outcome was reduced to a level of nonsignificance. In patients with K. pneumoniae BSIs, carbapenem resistance, advanced, age, and severity of underlying disease were independent predictors of outcome, whereas VIM production had no effect on mortality. The higher mortality associated with carbapenem resistance was probably mediated by the failure to provide effective therapy.Over the last few years, the reliance on carbapenems has been challenged owing to the wide spread of acquired metallo-␤-lactamases [MBLs] (2,11,20,25,31). Two dominant groups of acquired MBLs have been recognized: the IMP and VIM types. This class of enzymes is characterized by the ability to hydrolyze carbapenems and all available ␤-lactams with the exception of aztreonam. Moreover, since the MBL genes are linked to other resistance determinants within the same integron or plasmid, MBL-producing organisms are commonly multidrug resistant, further compromising our therapeutic options (8,26,28).MBLs have spread throughout the world with an overall trend moving from Pseudomonas aeruginosa into Enterobacteriaceae (9,10,14,16,18,22,23,28). Recently, there have been several reports on the emergence of VIM-producing Klebsiella pneumoniae (VPKP), mainly in Southern Europe (16,20). In Greece, VPKP isolates are endemic in various hospitals and cause life-threatening infections (5,8,29). Based on previous reports (30) and on the National Surveillance System for Antibiotic Resistance Database (www.mednet.gr/whonet/top .htm), the dissemination of such isolates appears to have occurred in a r...

Stay in an ICU, prior use of carbapenems and prior exposure to >3 different classes of antibiotics were independent predictors for VPKP BSIs. These findings provide guidance for antibiotic policies and infection control strategies to contain the spread of VPKP.