[Effect of glucose analogs on bofilm and expressions of related genes in Staphylococcus epidermidis]

Staphylococcus epidermidis, an opportunistic human pathogen, has become the most important cause of nosocomial infections in recent years. Its infection is mainly due to the ability to form biofilm on indwelling medical devices. To investigate the response mechanism of S. epidermidis to environment in biofilm formation and find efficient anti-biofilm methods, we investigated effects of two glucose analogs, 2-Deoxy-D-glucose (2DG) and Methyl-D-glucoside (MG), on biofilm formation, expression of related gene and changes of surface protein in S. epidermidis 97-337 with high biofilm formation capability and pathogenicity. The effect of MG on biofilm formation was more complex than that of 2-DG which is a strong inhibitor in S. epidermidis 97-337 growth. MG can induce biofilm formation of S. epidermidi 97-337 in low concentration and exhibited strong inhibition only in high concentration, and distinctly inhibited the primary attachment to poly-material. In S. epidermidi 97-337 cultured in media with MG, expressions of ica and AtlE were not be changed obviously in mRNA level, but mRNA expression of agr gene increased distinctly, and MG disturbed component of surface proteins of S. epidermidi 97-337. Glucose analogies MG can inhibit S. epidermidi 97-337 biofilm formation, and MG inhibition in initiating attachment dramatically contributes to it. MG inhibition effects result not from regulating the expression of ica and AtlE genes but from changing the protein components on surface by regulating agr gene expression, and it can be presumed that MG's competitive character in bacteria glycose metabolism is crucial factor for these effects.