Characterization of Helicobacter pylori interactions with sialylglycoconjugates using a resonant mirror biosensor.

A new optical biosensor technique based on the resonant mirror was used to characterize Helicobacter pylori strains according to their sialic acid binding, demonstrating the suitability of using intact bacteria in real-time measurements and classifying strains based on their binding abilities. Results obtained from both competition and displacement assays using different glycoconjugates confirmed that several, but not all, H.pylori strains express sialic acid-binding adhesin(s), specific for alpha-2,3-sialyllactose. The adhesin, removable from the bacterial surface by water extraction, is not related to other reported H.pylori cell surface proteins with binding ability to sialylated compounds such as sialylglycoceramides.