The purpose of this study was to determine the level of Listeria spp., especially L. monocytogenes, in mechanically separated turkey (MST) meat. During two trials of 25 samples each, Listeria spp. were selected by using two enrichments (University of Vermont-modified I and II) and plating to selective Palcam agar base. A multiplex polymerase chain reaction (PCR) was used to confirm Listeria isolations. The specificity of the multiplex PCR assay was evaluated with reference strains of Listeria from the National Animal Disease Center (NADC) Culture Collection. The Listeria spp. yields a single 938-bp product whereas L. monocytogenes yields the 938-bp product along with a 174-bp fragment. Results from Trial I and II indicated L. monocytogenes could not be detected by PCR in the UVM enrichment due perhaps to PCR inhibitors present in poultry fats and muscle myoglobin. However the multiplex PCR performed from suspect colonies grown on Palcam indicated 48 out of 54 (89%) of the MST meat harbored Listeria spp. Of those, 32 of 48 (67%) were positive for L. monocytogenes.
Iowa State University
Ramos, Ann M.; Wesley, Irene V.; Dickson, James S.; and Harmon, Karen, "Rapid Detection of Listeria monocytogenes in Mechanically Separated Turkey Meat" (1998). Swine Research Report, 1997. 39.