Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

M F Kristensen,G Zeng,T R Neu,R L Meyer,V Baelum,S Schlafer

doi:10.1080/20002297.2017.1379826

M F Kristensen, G Zeng + Show 4 more

Open Access

https://doi.org/10.1080/20002297.2017.1379826

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Abstract

ABSTRACTThe bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental caries or medical device–related infections. It further investigated if OPN’s effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN’s effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion in a dose-dependent manner for all investigated species (Actinomyces naeslundii, Actinomyces viscosus, Lactobacillus paracasei subsp. paracasei, Staphylococcus epidermidis, Streptococcus mitis, and Streptococcus oralis). Likewise, adhesion forces decreased after OPN treatment. No effect of OPN on the lectin-accessibility to glycoconjugates was found. OPN reduces the adhesion and adhesion force/energy of a variety of bacteria and has a potential therapeutic use for biofilm control. OPN acts upon bacterial adhesion without blocking cell surface glycoconjugates.

Highlights

Targeting bacterial adhesion to solid surfaces is a promising approach to prevent biofilm-related disease [1,2,3]
At a concentration of 460 μM, CGMP had a moderate effect on bacterial adhesion that was statistically significant for A. naeslundii and S. epidermidis
B. dentium, R. dentocariosa, S. mutans, and E. faecalis were included in the experiments, as they play a role in the caries process and in medical device–related infections, but none of these bacteria attached to the saliva-coated surface, irrespective of the presence of OPN

Summary

Introduction

Targeting bacterial adhesion to solid surfaces is a promising approach to prevent biofilm-related disease [1,2,3]. OPN was shown to bind different strains of Staphylococcus aureus and Streptococcus agalactiae and opsonize them for phagocytosis [13], but except for this finding and the results mentioned above, little is known about the interaction between osteopontin and bacteria. It is not yet understood how OPN interferes with adhesion, and if the effect is a general phenomenon that applies to other bacteria in the oral cavity. The study quantified how different concentrations of OPN affected the colonization of saliva-coated surfaces by these organisms and determined the effect of OPN on the adhesion force of selected bacteria using single-cell force spectroscopy (SCFS)

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Conclusion