Carbapenemase-producing Enterobacteriaceae during 2011-12 in the Bolzano area (Northern Italy): increasing diversity in a low-endemicity setting

The recent (2011-2012) distribution of carbapenemase determinants in Enterobacteriaceae was studied in the Bolzano area (Northern Italy). Low proportions of carbapenemase producers were found for Escherichia coli (0.2%), Citrobacter freundii (1.1%), Klebsiella pneumoniae (1.3%), Klebsiella oxytoca (1.6%) and Enterobacter spp (1.8%). Although VIM-1 remained the most common carbapenemase, the emergence of K. pneumoniae producing KPC-3 and of E. coli producing OXA-48 was observed. Of concern is the spread of the hyperepidemic strains E. coli ST131 producing VIM-1 and K. pneumoniae ST258 producing KPC-3. Low essential and category agreements between the reference broth microdilution and commercial methods were observed for carbapenems. © 2013 Elsevier Inc.