Abstract:To investigate the serotype, genealogy and infection-related genes of Listeria monocytogenes isolated from ready-to-eat foods.Methods Two hurdred and twenty-six Listeria monocytogenes isolated from ready-to-eat foods from 2007 to 2009 were collected from the National Foodborne Pathogen Surveillance Network. The serological typing was carried out using conventional serological typing and allele-specific oligonucleotide PCR (ASO-PCR). And their infection-related genes were detected by PCR. Results Among the 226 Listeria monocytogenes isolates from ready-to-eat foods, serovar 1/2a (41.59%,94/226) and 1/2b (40.71%,92/226) were dominant followed by serovar 1/2c (10.62%,24/226) and 4b (5.31%,12/226). The rate of human infection related serovar 1/2a, 1/2b and 4b was relatively high (87.61%,198/226), which indicated the potential risk in ready-to-eat foods. There were 105 strains of lieage I and 120 of lieage II, only one strain of lieage III. Virulence-associated genes were rarely missing in Listeria monocytogenes strains isolated from ready-to-eat foods indicating a high risk.Conclusion According to the serology and virulence genes distribution of Listeria monocytogenes isolated from ready-to-eat foods, food sanitation management should be strengthened to reduce the risk of infection.