Fig. 1 The role of bacterial adherence in Helicobacter pylori virulence (Mónica Oleastro and Armelle Ménard. 2013)
Fig. 2 Schematic diagram of Helicobacter pylori infection and pathogenesis (CY Kao, et al. 2016)
Helicobacter pylori (HP) is a Gram-negative, helix-shaped, microaerophilic bacterium that belongs to the family Helicobacteraceae, genus Helicobacter. It is usually found in the stomach. Pathogenesis of Helicobacter pylori depends on the fact that it can survive in the harsh gastric environment. This environment is thought to be an impossible zone for bacterium before, as it is characterized by peristalsis, acidity, and attack by phagocytes and released reactive oxygen species. It also plays a role in the development of stomach cancer and duodenal ulcers. More than half of the world's population harbor this bacterium in their upper gastrointestinal tract. But nearly 85% of them never experience any symptoms or complications. Individuals who were infected with Helicobacter pylori have a risk of developing peptic ulcers by 10% to 20%, and acquiring stomach cancer by about 1% to 2%.
Helicobacter pylori is a helix-shaped bacterium with a length of about 3 μm and a diameter of about 0.5 μm. It is microaerophilic, which means that it requires oxygen but at a lower concentration than that of the atmosphere. Helicobacter pylori consists of a large amount of strains with relatively large difference in their genomes. Its genome contains about 1.7 million base pairs, which encode more than 1500 genes. Helicobacter pylori possesses five major outer membrane protein (OMP) families, including porins, iron transporters, flagellum-associated proteins, known and putative adhesins and proteins of unidentified function. OMP of Helicobacter pylori contains lipopolysaccharide (LPS) and phospholipids, as well as other typical Gram-negative bacteria.
After entering the host stomach, H. pylori utilizes its urease activity to neutralize the hostile acidic condition at the beginning of infection. Flagella-mediated motility is then required for H. pylori to move toward host gastric epithelium cells, followed by specific interactions between bacterial adhesins with host cell receptors, which thus leads to successful colonization and persistent infection. Finally, H. pylori releases several effector proteins/toxins, including cytotoxin-associated gene A (CagA), and vacuolating cytotoxin A (VacA), causing host tissue damage.
With years of protein production experience and state-of-art facilities, Creative Diagnostics now can provide multiple high-quality Helicobacter pylori antigens to our customers with a cheaper price for various applications in both industry and academic programs. Welcome to contact us for more details.