Fig 4. OmpF is required for CDIEC536 dependent cell-cell adhesion.
(A) Sequence alignment of OmpF proteins from E. coli K-12, E. coli 536, S. Typhimurium LT2 and E. cloacae ATCC 13047 (ECL). Extracellular loop sequences are indicated above the alignment. (B) Analysis of cell-cell adhesion by flow cytometry. E. coli DL4905 (GFP+) inhibitors carrying cosmids pDAL660Δ1–39 (CDIEC93), pDAL866 (CDIEC536) or pWEB::TNC (CDI–) were mixed at a 5:1 ratio with DsRed-labeled CH12134 (ΔompF ompC EC536) target cells. Where indicated, target cells were complemented with plasmid-borne ompF from E. coli K-12, E. coli 536 (EC536), S. Typhimurium LT2 or E. cloacae (ECL). Cells suspensions were analyzed by flow cytometry using FL1 (533/30nm, GFP) and FL2 (585/40nm, DsRed) fluorophore filters. The percentage of bound target cells was calculated as the number of dual green/red fluorescent events divided by the total number of red fluorescent events. The average ± SEM is presented for two independent experiments. (C) Protein from the target bacteria in panel B was subjected to immunoblot analysis using polyclonal antisera against OmpC/F from E. coli K-12.