Figure 2.

Effect of growth temperature and growth conditions on the internalization of Salmonella in lettuce leaf. Salmonella was grown overnight in LB broth at the following temperatures: 37, 25, and 42°C with shaking (A), or in LB without shaking, as well as in LB plates, both at 37°C (B). Cells were washed and tested for internalization. The incidence of internalization was calculated and is presented as described in the legend of Figure 1. The data denote the average and SE of four independent experiments each performed in triplicates. Different letters indicate significant difference (P < 0.05) between means of internal fields harboring bacteria, according to ANOVA Tukey–Kramer Multiple Comparisons Test.