Research – Identification of genetic variations related to pathogenicity by whole genome sequencing of Listeria monocytogenes SMFM2019-FV16 isolated from enoki mushroom

In this study, the characteristics of Listeria monocytogenes isolated from enoki mushroom (Flammulina velutipes) collected from May to July 2019 were analyzed. The isolates were analyzed for strain characteristics, hemolysis, antibiotic resistance, heat resistance, and virulence genes (inlA, inlB, actA, plcB, and hlyA) were analyzed, and whole genome sequencing (WGS) analysis was performed for the strain with the highest risk. Seven isolates were obtained from some enoki mushroom samples. All isolates were β-hemolytic and had virulence genes. Antibiotic resistance test showed multi-drug resistance in L. monocytogenes strain SMFM2019-FV15 and SMFM2019-FV16. L. monocytogenes SMFM2019-FV16 showed higher heat resistance than the other isolates. According to the results L. monocytogenes SMFM2019-FV16 was selected as the strain with the highest risk. WGS for L. monocytogenes SMFM2019-FV16 showed that it had 14 antibiotic resistance genes and 43 virulence genes, and 35 single nucleotide variants in the 43 virulence genes were observed. These results indicate that these genetic variations might be related to the high risk of L. monocytogenes SMFM2019-FV16.