Pathogenesis of Helicobacter pylori Infection

Abstract

Three decades have passed since Warren and Marshall described the successful isolation and culture of Helicobacter pylori, the Gram-negative bacterium that colonizes the stomach of half the human population worldwide. Although it is documented that H. pylori infection is implicated in a range of disorders of the upper gastrointestinal tract, as well as associated organs, many aspects relating to host colonization, successful persistence and the pathophysiological mechanisms of this bacteria still remain controversial and are constantly being explored. Unceasing efforts to decipher the pathophysiology of H. pylori infection have illuminated the crucially important contribution of multifarious bacterial factors for H. pylori pathogenesis, in particular the cag pathogenicity island (PAI), the effector protein CagA and the vacuolating cytotoxin VacA. In addition, recent studies have provided insight into the importance of the gastrointestinal microbiota on the cumulative pathophysiology associated with H. pylori infections. This review focuses on the key findings of publications related to the pathogenesis of H. pylori infection published during the last year, with an emphasis on factors affecting colonization efficiency, cag PAI, CagA, VacA and gastrointestinal microbiota.

Systems-wide analyses of mucosal immune responses toHelicobacter pyloriat the interface between pathogenicity and symbiosis

“…For a detailed description of relevant pathogenicity factors we would like to refer the reader to recent review articles on this topic. 19,20 Physical contact and the localization of H. pylori within in the gastric mucosa are critical determinants for immunopathology. Approximately 20% of H. pylori organisms in the stomach adhere to the surface of gastric epithelial cells.…”

Inhibitory Activity of Mangiferin on Helicobacter Pylori-Induced Inflammation in Human Gastric Carcinoma Ags Cells

“…Shortly, 100 µL of H. pylori cell suspension (1×10 8 colony forming units/mL) was smeared onto nutrient agar plates. The sterile paper disks of 6 mm were saturated with different concentration (10,20,50 and 100 μg) of MF (based on the preliminary analysis; data not shown) dissolved in DMSO and impregnated on the agar surface (plate). DMSO alone was used as positive control (only H. pylori; HP group), and antibiotic amoxicillin (AMX, 10 µg/ml) was used as a standard for comparison.…”

“…In brief, AGS cells (5 × 10 5 /mL) were cultured in 24 well plates, and 500 μL of medium was added to each well and left for overnight at 37˚C. Then, H. pylori suspension (10 μL) and various concentration of MF (10,20,50, and 100 µg) or AMX (10 µg) were added and left overnight at 37˚C in 5% CO 2 incubator. Then the non-adherent bacteria were washed off, using PBS.…”

“…The pathogenesis of H. pylori infection is extremely complex owing to its multi-virulence factors like Cytotoxin-associated gene A (CagA), Cag pathogenicity island (Cag PAI), lipopolysaccharide (LPS), urease and Vacuolating cytotoxin A (VacA). Nevertheless, sustained inflammation, immunomodulation and oxidative stress (in the host) are the major reason for H. pylori-related diseases like peptic ulceration, gastritis, gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer (Lawal et al, 2014;Sgouras et al, 2015). Gastric cancer is a serious problem caused by H. pylori since it claims more lives in developing and undeveloped countries attributing to poor sanitation facility.…”

Nanotechnology-based drug delivery systems for control of microbial biofilms: a review

“…In addition, it also blocks the sterilization process of food, thus interfering in the digestion process. 54 The currently available therapy to eradicate this bacterium is complex and costly and presents severe side effects for the patients. 55 Bacterial prostatitis is a UTI that affects males of all ages.…”