Klebsiella pneumoniae Carbapenemase-producing Enterobacteria in Hospital, Singapore

WD. Re-emergence of tularemia in Ger-many: presence of Francisella tularensis in different rodent species in endemic areas. of the ecology of Francisella tularensis during an inter-epizootic period.laremia of European brown hare (Lepus europaeus): a pathological, histopatho-logical and immunhistochemical study. Klebsiella pneumoniae Carbapenemase-producing Enterobacteria in Hospital, Singapore To the Editor: During the past decade, enterobacteria that produce Klebsiella pneumoniae carbapene-mase (KPC) have become established in the United States and countries in South America and Europe (1). In Asia, KPC was reported in the People's Republic of China in 2007 (2) and subsequently in South Korea (3) and Taiwan (4). Public health agencies emphasize screening and strict contact precautions to control multidrug resistant Enterobacteriaceae (5). Routine testing for mechanisms of resistance facilitates detection of emerging carbapenem-resistant Enterobacteriaceae. In Singapore's 1,000-bed National University Hospital during November 2010–January 2011, we identifi ed New Delhi metallo-β-lactamase 1–producing Enterobacteriaceae in 2 clinical specimens but none that produced KPC (I. Venkatachalam et al., unpub. data). We conducted a laboratory screening study to determine the prevalence and nature of carbapenem-resistant Enterobacteriaceae in April 2011. Ethics committee approval was waived for this study. Testing of rectal swab samples is part of an established hospitalwide program for vancomycin-resistant enterococci screening. Using a scoring system to identify patients at high risk for vancomycin-resistant enterococci (6), we found that ≈2.5 specimens per 100 admissions were attained each month. During our study, we also tested these samples for carbapenemase-producing Enterobacteriaceae. During April–June 2011, we incubated specimens for 24 h in 10 mL tryptic soy broth containing 1 mg/L imipenem, then streaked 100 μL of the broth onto CHROMagar KPC (CHROMagar, Paris, France). Colonies detected after 24 h incubation at 35°C were identifi ed by using MALDI-TOF MS with a Microfl ex LT instrument (Bruker Daltonik GmbH, Leipzig, Germany). Imipenem and meropenem MICs for Enterobacteriacaeae were confi rmed by using Etests (bioMérieux, Marcy l'Etoile, France). Isolates with MIC >2 μg/mL underwent analysis with Metallo-β-Lactamase Confi rmative Identifi cation Pack (Rosco Diag-nostica, Taastrup, Denmark) and Etest MBL (bioMérieux) for metallo-β-lactamase production. Isolates suspected to be producers were genotypically confi rmed by PCR. Of the 201 nonduplicate samples processed, 79 microorganisms exhibited imipenem resistance and were isolated on CHROMagar KPC (Table). Among Enterobacteriaceae, carbapenem MIC >2 μg/mL was present in 1 E. aerogenes, 2 E. cloacae, and 4 K. pneumoniae isolates. One isolate (K. pneumoniae) had a positive combined disk test result with a pattern suggestive …