Fig. 7

Invasion and persistence assays of different strains of S. enterica grown in iron-rich and iron-depleted conditions prior to infection. Recipient SE819, transconjugant and wild type SE163A of S. enterica strains were grown in iron-rich and iron-depleted media overnight prior to infect human intestinal epithelial cells (Caco-2) with at MOI of 10. Bacterial invasion (a) and persistence assays (b) were performed 1 h and 48 h post infection, respectively. The error bars show the standard error of means for 2–3 biological replicates of two independent experiments. Student’s t-test was performed to determine the statistically significant difference between two groups of sample. A p value ≤0.05 was considered a significant difference between the two groups compared, as indicated by the asterisks. Statistically non-significant differences are indicated by “ns”