Performance of the EUCAST disc diffusion method and two MIC methods in detection of Enterobacteriaceae with reduced susceptibility to meropenem: the NordicAST CPE study.

• Published in: Journal of Antimicrobial Chemotherapy
• Main Authors: Haldorsen, Bjørg, Giske, Christian G, Hansen, Dennis S, Helgason, Kristjan Orri, Kahlmeter, Gunnar, Löhr, Iren H, Matuschek, Erika, Österblad, Monica, Rantakokko-Jalava, Kaisu, Wang, Mikala, Småbrekke, Lars, Samuelsen, Ørjan, Sundsfjord, Arnfinn
• Other Authors: 1 Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway. 2 Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden. 3 Department of Clinical Microbiology, Herlev and Gentofte Hospital, Herlev, Denmark. 4 Department of Clinical Microbiology, Landspitali University Hospital, Reykjavik, Iceland. 5 EUCAST Development Laboratory, Växjö, Sweden. 6 Department of Medical Microbiology, Stavanger University Hospital, Stavanger, Norway. 7 Bacterial Infections Unit, National Institute for Health and Welfare, Turku, Finland. 8 Clinical Microbiology Laboratory, Turku University Hospital, Turku, Finland. 9 Department of Clinical Microbiology, Aarhus University Hospital, Aarhus, Denmark. 10 Department of Pharmacy, Faculty of Health Sciences, UiT - the Arctic University of Norway, Tromsø, Norway. 11 Department of Medical Biology, Faculty of Health Sciences, UiT - the Arctic University of Norway, Tromsø, Norway.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press 2019
• Subjects: Norway; Northern Norway
• Online Access: http://hdl.handle.net/2336/620794; https://doi.org/10.1093/jac/dky276

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Download To examine performance of EUCAST disc diffusion and supplementary MIC methods for detection of Enterobacteriaceae with reduced susceptibility to meropenem using EUCAST screening recommendations. Sixty-one Nordic laboratories delivered data on EUCAST disc diffusion (n = 61), semi-automated meropenem MIC (n = 23; VITEK2, n = 20 and Phoenix, n = 3) and gradient meropenem MIC (n = 58) methods. The strains (n = 27) included the major carbapenemase classes (A, n = 4; B, n = 9; D, n = 6) involved in the global spread of carbapenemase-producing Enterobacteriaceae (CPE) and non-CPE strains (n = 8) covering a range of broth microdilution (BMD) meropenem MICs. A triplicate Klebsiella variicola (meropenem MIC 0.5 mg/L) harbouring OXA-48 and Escherichia coli ATCC 25922 showed an overall good precision. Meropenem zone diameters below the EUCAST screening cut-off (<27 mm) were reported for strains with MIC ≥1 mg/L (n = 21), irrespective of resistance mechanism. For three strains (MIC = 0.5 mg/L) with OXA-48/-181, eight laboratories provided meropenem zone diameters above the screening cut-off. Very major errors (VMEs) were not observed. The overall distributions of major errors (MEs) and minor errors (mEs) were 9% and 36% (disc diffusion), 26% and 18% (VITEK2) and 7% and 20% (gradient MIC), respectively. Differences in ME and mE distributions between disc diffusion and MIC gradient tests compared with semi-automated methods were significant (P < 0.0001), using BMD MICs as a reference for categorization. The EUCAST disc diffusion method is a robust method to screen for CPE but isolates with meropenem MICs <1 mg/L pose challenges. The high ME rate in semi-automated methods might deter appropriate use of carbapenems in CPE infections with limited therapeutic options. Northern Norway Regional Health Authority (Helse Nord RHF) Norwegian ...