Surface properties of Helicobacter mustelae and ferret gastrointestinal mucosa

Helicobacter mustelae is a gastric pathogen in ferrets that adheres to epithelial cells both in vitro and in vivo. In this study, the authors examine the role of surface hydrophobic properties in the adhesion of these organisms to eukaryotic cell surfaces. The surface properties of six H. mustelae strains were characterized by hydrophobic interaction chromatography (HIC), salt aggregation testing (SAT) and contact-angle measurement by axisymmetric drop-shape analysis (ADSA). Contact angles in multiple regions of the gastrointestinal tract, obtained from infected and uninfected ferrets, were also measured. The cell surface of H. mustelae was found to be hydrophilic by SAT but relatively hydrophobic by HIC. Contact-angle measurements for H.mustelae (mean 22.5 degrees, 95% confidence interval [CI] 9.3 degrees to 35.7 degrees) were higher than values previously reported for Helicobacter pylori (mean 12.1 degrees, 95% CI 2.0 degrees to 22.2 degrees, p < 0.05). The body of the stomach was more hydrophilic in infected ferrets (mean contact angle 59.9 degrees, 95% CI 52.5 degrees to 67.3 degrees) than in uninfected animals (mean contact angle 94.2 degrees, 95% CI 84.4 degrees to 104.0 degrees, p < 0.05). Reductions in the surface hydrophobicity of the ferrets' stomachs were correlated with the degree of mucosal inflammation (p < 0.01). These findings demonstrate that H. mustelae has surface properties comparable to those of H. pylori strains. Like the human stomach infected by H. pylori, there is a reduction in surface hydrophobicity of the ferret antrum associated with H. mustelae infection and the resulting mucosal inflammatory cell response.