Detection of Helicobacter pylori in saliva based on surface plasmon resonance by binding of Lewis b (Le^b) blood group antigen to specific adhesin BabA

Abstract

Helicobacter pylori affects about half of the population around the world. Therefore, timely and reliable diagnosis of the disease is required. Non-invasive detection of H. pylori is the technique of choice for infection control. Sample collection from saliva is non-invasive, but the bacteria load in human saliva is lower than in samples collected from the stomach, blood or stool. Hence, a detection method of high specificity and sensitivity is required. The purpose of this study was to evaluate the applicability of the Surface Plasmon Resonance (SPR) biosensor, based on the binding of Lewis b (Le^b) blood group antigen to the specific adhesin BabA, for H.pylori detection in saliva. Our studies on saliva artificially contaminated with H. pylori, demonstrated that the BabA - Leb binding reaction had high specificity. The results obtained indicated that there are two mechanisms that inhibit the viability of H. pylori. The first involves the direct interaction between H. pylori and the oral antagonistic bacteria, and the second involves the bactericidal effect of certain proteins produced by the oral background bacterial flora. Although the sensitivity of detection of the proposed method needs to be increased, the results obtained proved its applicability and feasibility for H. pylori detection in saliva and the good prospects it offers for both clinical application and as a rapid point-of-care test.

Keywords:

• Helicobacter pylori
• blood antigen
• SPR detection

Authors’ contributions

G. D. – conceptualization, investigation, formal analysis, writing part of the manuscript, funding, H. N. – conceptualization, investigation, resources, formal analysis, writing part of the manuscript, P.G.K – conceptualization, methodology, validation, writing part of the manuscript, V.K. – conceptualization, methodology, resources, V.M. – resources, measurements, H. K., P.V - measurements, E. H. – investigation, data curation, V. S. – investigation, V.K. – investigation, N. M. – supervision, funding. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s)

Data availability statement

The anonymized data that support the findings from this study are available from the corresponding and first authors (PGK, GD) upon reasonable request.

Additional information

Funding

This work was supported by the Bulgarian National Science Fund under Grant number KP-06-N33/1, from 13 December 2019 and by Bulgarian Ministry of Education and Science (MES), Project № D01-352 from 13 December 2023.