TABLE 6.

MBL detection techniques

Technique	Test	Substrate-inhibitor combination	Advantages	Disadvantages	Reference
Clinical microbiology	Disk approximation	Ceftazidime and 2-mercaptoproprionic acid	Easy to use	Disk and distance of disk placement not standardized and not always easy to interpret	6
	Disk diffusion	Imipenem and EDTA	Easy to use and relatively easy to interpret	Disk not standardized. MBL-producing bacteria can be imipenem sensitive	202
	Microdilution test	Imipenem and EDTA and 1,10-phenanthroline	Based on reduction in MICs, easy to interpret	Specialized and labor intensive, MBL-producing bacteria can be imipenem sensitive	99
	Etest	Imipenem and EDTA	Easy to use and relatively easy to interpret	MBL-producing bacteria can be imipenem sensitive and borderline cases may be missed	177
	Carbapenem hydrolysis	Meropenem and EDTA	Very sensitive and deemed to be the gold standard	Highly specialized, labor intensive, and interpretation not straightforward	180
Molecular detection	PCR for genes for IMP, VIM, etc.		Easy to perform, specific for gene family	Requires tailor-made DNA primers, cannot differentiate between variants, may not detect new variants	158
	DNA probes		Specialized, labor intensive	Probe required for each gene family, cannot differentiate between variants
	Cloning and sequencing		Molecular gold standard	Labor intensive, intepretation of data requires experience	167