Molecular Detection of Beta-lactam and Carbapenem Resistance

The DNA of isolated strains showing phenotypic resistance to beta-lactams and carbapenems was extracted using “Zymo DNA Mini Kit” extraction kits according to the manufacturer’s instructions. PCR was used to detect beta-lactam resistance genes (bla_TEM, bla_SHV, bla_OXA-1, bla_CTXM-1, bla_CTXM-9, and bla_CTXM-15) and carbapenem resistance genes (bla_KPC, bla_NDM, bla_IMP, bla_VIM, and bla_OXA-48) following the PCR conditions described by Dallenne et al. (33 (link)), Memariani et al. (34 (link)), and Cerezales et al. (35 (link)). All primer sequences are listed in Table 1. DNA fragments were analyzed by electrophoresis on a 2% agarose gel for 30 min at 100 V using BioRad Horizontal Electrophoresis System. The migration was imaged using the Biorad Gel Doc EQ imaging system, followed by interpretation of the results based on comparison of the migration of the fragments to the marker sizes (100 bp).