Use of meropenem Adatabs dissolved in MacConkey agar for screening NDM-1 positive Enterobacteriaceae in faecal surveillance cultures

SummaryAimsCarbapenem resistance due to metallo-β-lactamases (MBLs) in Enterobacteriaceae has gained much prominence in recent months. The emergence and subsequent spread of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes a potential threat in terms of the management of affected patients and institutional infection control efforts. We evaluated an in-house prepared meropenem impregnated Mac-Conkey agar versus CHROMagar KPC.MethodsThe lowest limit of detection (LLD) was compared for nine clinical isolates of NDM-1 producing Enterobacteriaceae on the above mentioned agar media.ResultsLLD was comparable for all the nine clinical isolates on both media. The cost of the antibiotic impregnated MacConkey agar was considerably lower (US$0.39) as compared to the commercial media, while its performance remained unaltered for a period of at least 8 weeks of storage.ConclusionThe in-house medium proved to be a suitable and cheap alternative to the CHROMagar KPC.