FIG 4.

Inhibition of A/E lesion formation by ketolides. Semiconfluent monolayers of Caco-2 cells were infected with ZAP198 at an MOI of 20 in the presence or the absence of the indicated concentrations of telithromycin (Tel) or solithromycin (Sol). After 4 or 5 h of incubation, cells were fixed in 4% PFA. Bacteria were stained with anti-O157 antigen detected with PE-conjugated secondary antibody, nuclei were stained with DAPI, and actin polymerization was detected with FITC-conjugated phalloidin. Orthogonal sections show actin polymerization beneath adherent bacteria, which is typical of A/E lesions. Confocal images were acquired as described in Materials and Methods.