Differentiation of virulence of Helicobacter pylori by matrix-assisted laser desorption/ionization mass spectrometry and multivariate analyses.

Background: The ability to determine the virulence of a Helicobacter pylori strain would be helpful for predicting the development of gastrointestinal disease and suggesting medical treatment.

Methods: A protocol based on matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS) was established for the efficient detection of peptides and proteins in extracts of H. pylori cells. Two multivariate statistical methods-principal component analysis (PCA) and hierarchical clustering analysis-were used to analyze the resulting MALDI mass spectra of reference strains and clinical isolated/inoculated strains.

Results: Based on differences in their peptide and protein profiles, H. pylori strains having similar virulence genotypes were grouped together on the PCA score plot. Hierarchical cluster analysis revealed high conformity between the protein profiles and the respective virulence genotypes. The inoculated H. pylori strain, which was clustered in the same group with the high-virulence reference strains, also resulted in severe histopathological lesions in gerbils.

Conclusions: MALDI-TOF MS combined with multivariate analyses shows the ability to rapidly differentiate H. pylori strains in terms of their virulence.