Adherence of S-layer protein-coated cell wall fragments to IPEC-1 cells. A) The IPEC-1 cell adherence of CWF, coated or uncoated by the indicated S-layer proteins, expressed by quantitative means. The mean number of adherent CWF was quantitated from 20 randomly selected fields of 3.5 x 104 μm2 and the results are presented as means and standard deviations from one representative experiment out of three; letters above the bars refer to Figures C-H below. B) An electron micrograph of purified CWF of L. amylovorus DSM 16698. Scale bar, 0.5 μm. C-H) Examples of the adherence of Slp-coated and uncoated L. amylovorus CWF to IPEC-1 cells as detected by fluorescence. The figures show the adherence of uncoated L. amylovorus DSM 16698 CWF (C) and the adherence of the following Slp/CWF complexes: DSM 16698 CWF/SlpA (D), DSM 16698 CWF/SlpB (E), DSM 16698 CWF/SlpC (F), DSM 20531T CWF/SlpA (G) and GRL 1117 CWF/SlpA (H). The rightmost figures display the corresponding fields viewed with phase contrast optics. The inset in (D) shows a magnified image of a cell wall fragment. Arrowheads in (G) indicate precipitated Slp. Scale bars, 10 μm.