Detection of Helicobacter pylori in saliva based on surface plasmon resonance by binding of Lewis b (Leb) 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 (Leb) 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