Relationships between hydrophobicity and biofilm formation in Streptococcus agalactiae strains

Streptococcus agalactiae (GBS) is a human pathogen, that forms biofilms in vitro with variable efficiency. Aim of this study was to investigate the relationships between hydrophobicity and the ability of GBS to form biofilm. Twenty strains of GBS were investigated for the purpose. Biofilm experiments were performed, in unmodified atmosphere, in 96-well polystyrene microtiter plates containing Todd-Hewitt Broth. Increasing concentrations of glucose were also investigated for their influence on both hydrophobicity and biofilm production. The quantitative measurement was achieved by means of colorimetric methods using crystal violet. The hydrophobicity was investigated by using the hexadecane test, and expressed as percent of hydrophobicity. The hydrophobicity varied a little in most cases and independently of glucose concentrations, while BI increased with increasing concentration of glucose. Although most of the strains had a hydrophobicity index of > 80%, any correlation between hydrophobicity and biofilm formation has not been found