Cell proliferation of Cal29 cells after infection with BCG S4-Jena and TICE. Proliferation was measured by WST-1. Results are reported as percentage inhibition of cell proliferation, where the optical density value from untreated cells was set as 100% of proliferation. Test was performed eight times by duplicate measurements. B-D: Effects of BCG strain S4-Jena and TICE on the cell membrane in Cal29 cells using scanning electron microscopy. Untreated Cal29 cells are showing a normal surface (B). Cal29 cells treated with TICE strain for 12 h (C) show a similar appearance as untreated cells. Infection with S4-Jena strain led to morphological changes in the cells after 12 h (D).