Fibronectin(Fn), high molecular weight glycoprotein which is found in blood and other body fluids as a soluble form, in connective tissues as an insoluble form and is associated with basement membranes. The interaction of Staphylococcus aureus(S.
aureus) and Escherichia Coli) with Fn was studied to identify the potential of Fn initial involement in the events of the pathogenesis of wound and urinary tract infections Thirteen strains of S. aureus and 16 strains of E. coli isolated from
wound
and
urinary tract infections were employed for this study. When the amount of 125I-labelled Fn bound to S. aureus strain Cowan I(Cowan I) was set as 100%, ten strains of S. aureus were bound more than 100% of the Cowan I, while S. aureus strain
88DT29
and
88DT29 and 88DT 36 were bound more than 200%.Another 3 strains of S. aureus also bound more than 80% compared with Cowan I. To characterize the specific binding, a low concentration(5μg/ml) and a high concentration(100μg/ml) of unlabelled Fn
were
added simultaneously during the incubation period. The inhibition percentage of the low concentration of unlabelled Fn ranged from 0% to 28.0%, while the inhibition percentage of the high concentration showed above 80% inhibition to S. aureus
strains.
On the other hand, no E. Coli strains were bound above 45% compared with the amount bound to Cowan I. The inhibitin percentage of the high concentration of unlabelled Fn was less than 4.1% in E. coli strains. Showing no difference in 125I-Fn
binding
capacity between wound and urine isolates E. coli. For the electron microscopic studies, probes constructd by adsorbing Fn to colloidal gold beads(Fn-Au). The findings of transmission electron microscopy and scanning electron microscopy showed
that
many
Fn-Au bound to the surface of S. aureus strain 88DT36 in suspension, while few Fn-Au were appeared on the surface of E. coli strain 89E67. In conclusion, this study showes that S. aureus bound specifically to Fn, while E. coli did not bind
specifically
to Fn.
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