Molecular Epidemiology of Invasive Listeriosis due to Listeria monocytogenes in a Spanish Hospital over a Nine-Year Study Period, 2006–2014

Figure 2

Invasion assays for the 17 clinical isolates of Listeria monocytogenes in HeLa epithelial cells. The mean number of internalised bacteria as a percentage of the initial inoculum is shown on the -axis. The error bars show the standard error of two independent experiments, each performed in duplicate. The wild-type L. monocytogenes P14 and noninvasive L. monocytogenes ΔprfA strains were included, to assess the reproducibility of the experiments.