Phenotypic detection of carbapenemase and metallo-β-lactamase production by Modified Hodge test (MHT) and Combined disks diffusion (CDD) method, respectively. A, The presence of clover leaf-type indentation at the intersection indicates the positive test organism while carbapenemase negative organism lack of the clover leaf-type indentation at the intersection; B, Positive results are shown by enlarged zone of inhibition in the presence of EDTA. IMI, Imipenem disc; MEM, meropenem disc; EDTA, ethylene-diamine tetra acetic acid.