FIG. 2.

Expression of chimeric fimbriae. (A) Congo red binding assay. The amount of Congo red bound by 1 A₆₅₀ unit of Salmonella cells from TCR plates was measured. The SL3261 mutants can bind similar amounts of Congo red as parent strain SL3261, but the amount bound by the ΔAgfA strain was much less than that bound by the other strains (P < 0.05). (B) Immunofluorescence of SL3261 strains by rabbit anti-AgfA serum. Cells were scraped from T medium and fixed on glass slides. AgfA-specific antiserum was applied. (i) strain SL3261; (ii) strain SL3261 ΔAgfA; (iii) strain SL3261-ESO9, and (iv) strain SL3261-ESO11. Scale bars, 5 μm.