Adherence of Pseudomonas aeruginosa to tracheal epithelial cells of mink. Studies on bacterial hydrophobicity and elastase production.

Pseudomonas aeruginosa strains, producing variable elastase activity, were evaluated for adherence ability to mink tracheal epithelial cells. Attachment was studied in relation to surface hydrophobic properties of bacteria. Elastase production and bacterial hydrophobicity were measured during growth up to 48 hr. A high elastasolytic strain B1 adhered well; it exhibited a mean of 39.0 bacteria per epithelial cell. Adherence of the organisms was not correlated with the degree of hydrophobicity, since more hydrophobic strains do not adhere better. Bacterial surface becomes less hydrophobic during exponential growth-phase (up to 6 h). Hydrophobicity then slightly increases up to 48 h. No correlation between elastase production and changes in surface hydrophobicity was found, since treatment of washed bacteria from either early exponential or later decline-growth phases with different concentrations of elastase did not markedly affect bacterial hydrophobicity. The results indicate that strains with high or active elastase production adhered better than low or inactive elastase-producing strains. Furthermore, bacterial surface hydrophobicity does not seem to play a major role in adherence.