Relative hydrophobicities of Actinomyces viscosus and Actinomyces naeslundii strains and their adsorption to saliva-treated hydroxyapatite

Abstract

The present study examined 42 strains ofAcfinomyces spp. to determine whether adsorption to saliva-treated hydroxyapatite (SHA) of the selected strains of this prominent group of dental-plaque bacteria correlated with hydrophobicity. The relative hydrophobicity of the strains was determined by their adsorption to hydrophobic gels (i.e., phenyl-Sepharose) and their aggregation in ammonium sulfate. Within serogroups the relative hydrophobicity for the strains was similar. The relative adsorption of strains to SHA was also similar within the respective serogroups. Strains which were relatively hydrophobic, as judged by their binding to the hydrophobic gel and aggregation in low concentrations of ammonium sulfate, adsorbed well to SHA. Strains which adsorbed poorly to SHA were relatively hydrophilic since they did not bind well to the hydrophobic gel and were only aggregated in relatively high concentrations of ammonium sulfate. Tween 80, a nonionic detergent known to inhibit hydrophobic interactions, blocked binding of cells to the hydrophobic gel, suggesting that hydrophobic interactions had been inhibited. However, Tween 80 exhibited no influence on the adsorption of cells to SHA. Thus, although there was a strong statistical correlation between the relative hydrophobicity of a strain and its adsorption to SHA, the data were consistent with the view that other interactions, such as ionic bonds and interactions between complimentary macromolecules, are involved in adsorption of the Actinomyces strains to SHA.

Feeding selection of heterotrophic marine nanoflagellates based on the surface hydrophobicity of their picoplankton prey

“…Following, generally, the HIC method described previously (Smyth et al 1978;Hermansson et al 1982), replicate seawater subsamples were passed, respectively, through preconditioned high-performance liquid chromatography preparatory columns (Waters) containing 100 mg of hydrophobic (C18) or hydrophilic (Diol) resin. A relative index of cellsurface hydrophobicity (HIC index) was then computed using the expression (Clark et al 1985)…”

The hydrophobicity of Streptococcus salivarius strain HB and mutants deficient in adhesion to saliva-coated hydroxyapatite

“…Hydrophobic interactions may contribute to the adhesion of viridans streptococci to oral surfaces in vitro (Nesbitt et al 1982;Hogg et al 1983;Clark et al 1985) and Svanberg et al (1984) have shown that relatively highly hydrophobic strains of Streptococcus mutans implant significantly better in human mouths than less hydrophobic strains of the same species.…”

No relationship between the cell surface hydrophobicity of coagulase-negative staphylococci and their ability to adhere onto fluorinated poly(ethylene-propylene)

“…Therefore, our findings show that the cell surface of various non-encapsulated and encapsulated CN Staph strains is rather heterogeneous. It may be that strains with a high degree of cell surface similarity have been used in a number of studies reporting a rather good linear correlation between the SAT value and the bacterial adherence to octane [26] or to octylsepharose [19,27,28].…”