ACTA1 and infection: We noticed that in this strain (EGDe-ΔactA+actA), actA was not regulated as in the wild type EGDe strain, since after 3 days of infection in JEG3 cells, most EGDe-ΔactA+actA bacteria produced ActA at the bacterial surface and polymerized actin, in contrast to the wild type strain (S10 Fig).