Hydrophobic adherence and phase variation in Bordetella pertussis

The hydrophobicity of Bordetella pertussis was assayed by measuring the ability of cells in suspension to adhere to a polystyrene surface. The quantity of adhered bacteria was measured by the binding of enzyme-conjugated anti B. pertussis antibodies. Hydrophobic adherence of non-pathogenic variant strains was about 20% of that exhibited by pathogenic strains. Hydrophobicity was a stable trait as it did not change with passaging or storage. Assays of a series of characterized stable variants suggested that the Filamentous Hemagglutinin (FHA) is the cell surface moiety responsible for hydrophobic adherence in B. pertussis.