Prevalence and mechanisms of resistance to carbapenems in Enterobacteriaceae isolates from 24 hospitals in Belgium

To determine the point prevalence of carbapenem-non-susceptible Enterobacteriaceae (CNSE) and carbapenemase-producing Enterobacteriaceae (CPE) isolates among hospitalized patients in Belgium. Twenty-four hospital-based laboratories prospectively collected 200 non-duplicated Enterobacteriaceae isolates from clinical specimens of hospitalized patients over a 2 month period. All isolates were screened locally for decreased susceptibility to carbapenem drugs using a disc diffusion method according to CLSI interpretative criteria. CNSE strains were referred centrally for confirmation of carbapenemase by phenotypic and molecular testing. From February to April 2012, 158 of the 4564 screened Enterobacteriaceae isolates were categorized as non-susceptible to carbapenems, resulting in a point prevalence of CNSE of 3.5 (95 CI: 2.94.2; range per centre: 0.58.5). Of the 125 referred CNSE isolates, 11 Klebsiella pneumoniae isolates [OXA-48 (n7), KPC type (n3) and NDM type (n1)], 1 OXA-48-positive Escherichia coli isolate and 1 KPC-positive Klebsiella oxytoca isolate were detected in eight hospitals. None of the 72 carbapenem-non-susceptible Enterobacter spp. isolates were confirmed as CPE. The minimal estimated point prevalence of CPE isolates was 0.28 (13/4564; 95 CI: 0.130.44) overall (range per centre: 01.5). Despite the overall low prevalence of CNSE found in this study, the detection of CPE isolates in one-third of the participating centres raises concerns and highly suggests the spread and establishment of CPE in Belgian hospitals.