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ow nloaded from 2 Abstract 1 Detection of class A serine-carbapenemases among Enterobacteriaceae remains a 2 challenging issue. Methods for routine use in clinical microbiology laboratories for their 3 identification have not been standardized to date. We developed a novel screening 4 methodology suitable for countries with high basal levels of carbapenem resistance due 5 to non-carbapenemase mechanisms and standardized several simple confirmatory 6 methods that allow recognition of class A carbapenemase-producing bacteria, including 7 KPC, Sme, IMI, NMC-A, GES, using boronic acid (BA) derivatives. A total of 28 8 genetically unrelated Enterobacteriaceae strains producing several class A 9 carbapenemases were tested. Thirty-eight genetically unrelated negative controls were 10 included. The isolates were tested by MIC and disk diffusion against imipenem (IPM), 11 meropenem (MEM) and ertapenem (ETP) in order to select appropriate tools for 1