Listeriosis is a foodborne disease caused by the pathogenic Listeria monocytogenes and is considered as a
serious health problem due to the severity of symptoms and its high mortality rate. Listeria genus is
divided into six species and especially L. monocytogenes is an important foodborne pathogen in humans
and livestock. Recently, other Listeria species are reported as pathogenic strains in decayed foods and
environments as well. High mortality rate of listeriosis demands for rapid methods to detect the potential
presence of the food pathogens in the food industry. We have developed a multiplex PCR for rapid
and simultaneous detection of six Listeria species including Listeria grayi, Listeria innocua, Listeria ivanovii,
L. monocytogenes, Listeria seeligeri and Listeria welshimeri to identify specific Listeria species in processed
foods. The optimized multiplex PCR in this study utilized one Listeria genus specific and each Listeria
species-specific primer pairs. Each primer pair yields the products of 370-bp for Listeria genus-specific,
201-bp for L. grayi-specific, 749-bp for L. innocua-specific, 463-bp for L. ivanovii-specific, 509-bp for
L. monocytogenes-specific, 673-bp for L. seeligeri-specific and 281-bp for L. welshimeri-specific. We have
successfully applied multiplex PCR strategy to 93 Listeria isolates from processed meat products to
determine specific Listeria species and out of which 81 strains of L. monocytogenes, 10 strains of L. innocua
and 2 strains of L. welshimeri were identified. This established multiplex PCR provides rapid and reliable
results and will be useful for the detection of Listeria species in contaminated food products and clinical
samples.