Fig. 6.

Intracellular replication is affected by pre-invasion growth conditions. Infected HeLa cells were lysed for enumeration of intracellular S. Typhimurium (a) or fixed and processed for immunofluorescence using anti-LPS and anti-LAMP1 antibodies (b). To obtain comparable invasion, cells were infected with an m.o.i. of approximately 50–60 for aer-LL and approximately 150–180 for μaer-ST. The numbers of intracellular aer-LL (filled symbols/bars) or μaer-ST (open symbols/bars) S. Typhimurium with coincident LAMP1 staining cell were scored visually by fluorescence microscopy. Means±sd from three independent experiments are shown. *P<0.001, Bonferroni's post-hoc test.