Figure 5. Transmission electron micrographs of SEPEC 8 (fimH⁺, flu⁺, csgA⁻, mat⁻, iha⁻, gimB⁻, ibeA⁻, tia⁻, neuC⁻) adhesion and invasion after 3 h of incubation with Vero cells in the presence or absence of D-mannose. A, Bacteria that adhered to the cell surface (arrow) and intracellular bacteria in the absence of D-mannose. B, A group of four bacteria that suggests intracellular bacterial replication in the absence of D-mannose.