Figure 1.

Adhering Afa/Dr DAEC C1845 bacteria at an early stage of adhesion onto human enterocyte-like Caco-2/TC7 cells. Confluent differentiated Caco-2/TC7 cells were infected apically at 37°C in a 10% CO₂/90% air atmosphere for three hours with C1845 bacteria (10⁸ cfu/well). (A, B) Infected cell monolayers processed for light microscopic examination of semithin sections perpendicular to the bottom of the flask showed apically adherent C1845 bacteria (magnification ×40 in (A); ×100 in (B)). (C, D) Low and high magnification of transmission electron micrographs of adhering bacteria showing bacteria engulfed within microvilli (C) and a bacteria associated with multiple elongated microvilli (D) (magnification ×4000 and ×8000, respectively).