Basis and efficiency of diagnostic methods of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a micro-aerophilic, Gram-negative and flagellated bacterium which was first isolated from a human gastric biopsy specimen in 1983. This organism is probably the most common chronic bacterial infection of humans, present in almost half of the world population. The high clinical relevance of H. pylori infection has stimulated the development of numerous diagnostic methods. These methods can be classified as invasive, i.e. those that detect H. pylori directly in gastric biopsy specimens, or non-invasive, i.e, based on the study of various samples (e.g. serum, urine, breath air), which indirectly indicate the presence of H. pylori. Recently, enzyme immunoassays (EIA) for direct detection of H. pylori antigens in the stool have been developed and widely used because of their full non-invasive nature. There are two groups of the EIAs including polyclonal antibody-based stool antigen tests and monoclonal antibody-based stool antigen tests. The application of specific polyclonal antibodies against H. pylori-specific antigens such as alkyl hydro peroxide reductase (AhpC) may increase the efficacy and the specificity of polyclonal antibody-based stool antigen tests.