Effect of pharynx epithelial cells surface desialylation on receptor-mediated adherence of Staphylococcus aureus.

ABSTRACT

AIMS: To characterize the interaction between cell surface carbohydrates and Staphylococcus aureus. METHODS AND RESULTS: In the present study, in vitro adherence of S. aureus to Detroit 562 cells, amount of cell surface desialylation and effect of subterminal monosaccharides on desialylated glycoproteins on adherence was studied with colony counting, HPLC, fluorescence microscopy and fluorometric techniques. According to our findings, S. aureus adherence to pharynx cells was enhanced (40%) after neuraminidase treatment, and neuraminidase also cleave great amount of Detroit 562 cells surface sialic acid (39-60%). Adherence assay with various monosaccharides-pretreated bacteria, and lectin competitive inhibition, showed that the residual subterminal galactose, fucose and N-acetyl-D-glucosamine remaining on desialylated Detroit 562 cell surface glycoproteins responsible for this binding. CONCLUSION: The results are the first to show that galactose, fucose and N-acetyl-D-glucosamine remaining on desialylated pharynx cell surface glycoproteins serve as the adhesine receptors for S. aureus. SIGNIFICANCE AND IMPACT OF THE STUDY This study may explain the predisposition of severe S. aureus pneumonia complication in respiratory viral infections.