Occurrence, Persistence, and Virulence Potential of Listeria ivanovii in Foods and Food Processing Environments in the Republic of Ireland

Figure 4

Invasive potential of wild-type L. ivanovii isolates in a CACO-2 epithelial cell assay. The strains were incubated with CACO-2 cells in vitro for one hour and levels of bacterial invasion were subsequently measured. For comparison, invasive (EGDe) and noninvasive (PMSC1) strains of L. monocytogenes were also examined. Data represents % invasion efficacy (relative to Listeria numbers initially added per well). Statistical significance was determined using one-way ANOVA and the Dunnett post hoc test with all strains compared to L. monocytogenes EGDe (). All strains displayed statistically higher () levels of invasion efficiency relative to the PMSC1 strain.