A PCR-based strategy was used to clone and express the genes coding for Qnr-like pentapeptidic proteins of E. faecalis ATCC 29212, E. faecalis V583, E. faecium BM4147, Listeria monocytogenes 868 (clinical isolate), Clostridium perfringens 455 (clinical isolate) and Bacillus cereus ATCC 11778 in pPCR-Script vector (Stratagene) in Escherichia coli DH10B.