Detection of Listeria monocytogenes in milk by the polymerase chain reaction

A on the polymerase chain reaction (PCR) method based was developed for det ection of Listeria monocytogenes in milk samples after enrichment culture. It consists of culturing samples in Listeria enrichment broth, followed by DNA extraction and detection of the organism using PCR. Dilutions of L. mon ocytogenes in milk were subjected to PCR amplification after enrichment cul ture. When determing the sensitivity of the method, it was found to be poss ible to detect 37 CFU (colony forming unit gl/ml) of the bacterium in milk. The method was assessed as a sensitive, specific, times-saving and practic al way of detecting L. monocytogenes in milk samples.