Relative surface hydrophobicity, antigen K1 and haemagglutinating activity are associated in Escherichia coli.

Hydrophobic property of 136 Escherichia coli strains was examined by salt aggregation test (SAT). Out of the tested strains 61 were SAT positive. The correlations among the surface properties characterized by SAT and other phenotypical properties, e.g. mannose resistant haemagglutinating activity (MRHA), mannose sensitive haemagglutinating activity (MSHA), presence of antigen K1 and adsorption to Al(OH)3 gel were examined. The results showed that (i) Possession of antigen K1 provides the bacterial cell a hydrophilic character and covers its relative surface hydrophobicity; (ii) Correlation exists between the relative hydrophobicity of the bacteria determined by SAT and their haemagglutinating activity. SAT values are also influenced by non haemagglutinating fimbriae and also by other non fimbrial structures; (iii) The hydrophilic surface characters are mainly expressed by the results of adsorption to Al(OH)3 gel and the hydrophobic characters rather by the SAT values.