Emergence of OXA-48-producing Klebsiella pneumoniae and the novel carbapenemases OXA-244 and OXA-245 in Spain

摘要

Objectives: To describe the molecular and population-level characterization of a selected group of OXA-48-like-producing Klebsiella pneumoniae isolates collected in Spain between January 2011 and May 2012. Methods: During the study period, 151 OXA-48-like-producing K. pneumoniae isolates were collected from 10 hospitals in six different Spanish regions. From these, a representative sample of 21 isolates that caused hospital outbreaks and single infections was selected for further in-depth analysis. Molecular epidemiology was investigated using PFGE and multilocus sequence typing (MLST). Resistance genes were characterized by PCR and sequencing. Plasmids carrying blaOXA-48-like were studied by PFGE with S1 nuclease digestion. Results: All 21 isolates had ertapenem MICs ≥1 mg/L, but 47.6% remained susceptible to imipenem and meropenem; blaOXA-48 was identified in 19 isolates (90.5%) and the novel blaOXA-244 and blaOXA-245 genes were detected in 1 isolate each. With one exception, all isolates that contained blaOXA-48-like also contained blaCTX-M-15. PFGE typing revealed six clusters comprising isolates that belonged to MLST types ST11, ST16, ST392, ST405, ST437 and ST663, respectively. Two main clusters were identified: PFGE cluster 1 (12 isolates, belonging either to ST405 or ST663, from seven hospitals), and PFGE cluster 2 (4 ST16 isolates from two hospitals). Six of seven donor isolates conjugated successfully; blaOXA-48-like (but not blaCTX-M-15) was carried on ~60 kb Inc L/M plasmids. Conclusions: Multidrug-resistant K. pneumoniae producing OXA-48-like carbapenemase are emerging as important pathogens in Spain due to intra- and inter-hospital, clonal and non-clonal dissemination. The Author 2012. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.