Figure 6.

Adhesion of S. gordonii strains to human cellular fibronectin (cFn). Microtitre plate wells were coated with cFn (1 μg per well), blocked with BSA, and then incubated with streptococcal cells (5 × 10⁷ per well) for 2 hr at 37°C. Bacterial cells adhered (black columns) were quantified by staining with crystal violet as described in 4. Wells coated with cFn were also incubated with 0.001 U neuraminidase (sialidase) for 2 hr at 37°C, washed, blocked with BSA and then incubated with streptococcal cells (grey shaded columns). Expression of PadA or Hsa proteins by complemented strains was induced with 10 ng or 50 ng nisin ml⁻¹. Error bars represent ±SEM from three independent experiments (n = 3). * P < 0.05 for comparisons indicated; § P < 0.05 for neuraminidase‐treated cFn versus untreated