Three-decade failure to eradication of refractory Helicobacter pylori infec-tion and recent efforts to eradicate the infection

Author(s):  
Majid Taati Moghadam ◽  
Zahra Chegini ◽  
Amin Norouzi ◽  
Amin Sadeghi Dosari ◽  
Aref Shariati

Background: Helicobacter pylori causes dangerous and deadly diseases such as gastric cancer and duodenal ulcers. Eradication and treatment of this bacterium are very important due to the deadly diseases caused by H. pylori and the high cost of treatment for countries. So, we present a complete list of the most important causes of failure in the treatment and eradication of H. pylori, and addresses new therapeutic methods that may be effective in controlling this bacterium in the future. Results: Many efforts have been made to control and eradicate this bacterium over the years, but no success has been achieved since its eradication is a complex process affected by the bacterial properties and host factors. Previous studies have shown that various factors are involved in failure to eradicate H. pylori, such as new genotypes of the bacterium with higher pathogenicity, inappropriate patient cooperation, mutations, biofilm formation and dormant forms that cause antibiotic resistance, acidic stomach pH, high bacterial load, smoking, immunosuppressive features and intracellular occurrence of H. pylori. On the other hand, recent studies reported that the use of probiotics, nanoparticles, antimicrobial peptides, natural product and vaccine can be helpful in the treatment and eradication of H. pylori infections. Conclusion: Eradication of H. pylori is crucial for the treatment of important diseases such as gastric cancer. Therefore, it seems that identifying the failure causes of treating this bacterium can be helpful in controlling the infections. Besides, further studies on new therapeutic strategies may help eradicate H. pylori in the future.

Author(s):  
Taishi Kayano ◽  
Ki-Deok Lee ◽  
Hiroshi Nishiura

Background. Although the seroprevalence against Helicobacter pylori (H. pylori) in Japan has declined over the birth year, Japanese people have yet exhibited a relatively high risk of gastric cancer. The present study employed mathematical models to estimate the time- and age-dependent force of infection with H. pylori in Japan, predicting the future seroprevalence by time and age. Methods. We investigated the published seroprevalence data against H. pylori in Japan from 1980–2018. Solving the McKendrick partial differential equation model, the seroprevalence was modeled as a function of survey year and age. Maximum likelihood estimation was conducted to estimate parameters governing the time- and age-dependent force of infection. Results. Among all fitted models, the time-dependent and age-independent model with an exponentially decaying force of infection over years was most favored. Fitted models indicated that the force of infection started to decrease during and/or shortly after the World War II. Using the parameterized model, the predicted fraction seropositive at the age of 40 years in 2018 was 0.22, but it is expected to decrease to 0.13 in 2030 and 0.05 in 2050, respectively. Conclusion. The time dependence was consistent with the decline in the force of infection as a function of the birth year. The force of infection has continuously and greatly declined over time, implying the diminished transmission of H. pylori through the time course and small chance of persistence. These findings are critical to anticipate the future decline in gastric cancer incidence.


2022 ◽  
Vol 67 (4) ◽  
pp. 299-305
Author(s):  
Xiaohui Guo ◽  
Binghua Yin ◽  
Can Wang ◽  
Huazhi Huo ◽  
Zahra Aziziaram

Helicobacter pylori bacterium is one of the most common bacterial infections globally and is the leading cause of indigestion, gastric and duodenal ulcers, and gastric cancer. This bacterium can escape the antibacterial effects of stomach acid by adapting to the inner layers of the stomach. It combines with the natural sugars in the gastric mucosa. The compound is so effective that it makes bacterium resistant. For genes related to the pathogenesis of H. pylori, using the existence of genes such as cagA, hopQI, and hopQII, PCR is performed on some of these genes to amplify fragments of different lengths. One of the less-studied cases is that two or more pathogenic genes are simultaneously associated with H. pylori. This study examined the frequency of diseases and healthy individuals infected with H. pylori and cagA and hopQII genotypes. To diagnose H. pylori infection in healthy and stomach cancer patients, the PCR products are electrophoresed on the agarose gel after glmM gene amplification by PCR. To this aim, stomach tissue biopsies were used for patients, and saliva was used for healthy individuals. For this purpose, 150 gastric biopsy samples from stomach cancer patients and 150 saliva samples from healthy people were collected. Data showed a significant relationship between the coexistence of two genes, cagA and hopQII, and stomach cancer. 34.2% of patients and 10.1% of healthy individuals showed two genotypes, while other healthy people (89.9%) infected with H. pylori did not have this genotype. Therefore, the simultaneous presence of these two bacterial genes in human societies can be an essential biomarker for the diagnosis and prognosis of gastric cancer.


2008 ◽  
Vol 76 (5) ◽  
pp. 2235-2239 ◽  
Author(s):  
Maria Kaparakis ◽  
Anna K. Walduck ◽  
Jason D. Price ◽  
John S. Pedersen ◽  
Nico van Rooijen ◽  
...  

ABSTRACT Helicobacter pylori is the etiological agent of human chronic gastritis, a condition seen as a precursor to the development of gastrointestinal ulcers or gastric cancer. This study utilized the murine model of chronic H. pylori infection to characterize the role of macrophages in the induction of specific immune responses and gastritis and in the control of the bacterial burden following H. pylori infection and vaccination. Drug-loaded liposomes were injected intravenously to deplete macrophages from C57BL/6 mice, and effective removal of CD11b+ cells from the spleens and stomachs of mice was confirmed by immunofluorescence microscopy. Transient elimination of macrophages from C57BL/6 mice during the early period of infection reduced the gastric pathology induced by H. pylori SS1 but did not affect the bacterial load in the stomach. These data suggest that macrophages are important to the severity of gastric inflammation during H. pylori infection.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 168
Author(s):  
Ruyue Fan ◽  
Xiurui Han ◽  
Yanan Gong ◽  
Lihua He ◽  
Zhijing Xue ◽  
...  

Helicobacter pylori (H. pylori) adhesion to human gastric epithelial cells is closely linked with fucosylated glycans. Therefore, investigation of fucosylation in the interaction of gastric epithelial cells with H. pylori is critical. In this study we used lectin microarrays to detect the expression of fucosylated glycans in gastric epithelial cells (GES-1) infected with H. pylori strains isolated from patients with different diseases including chronic gastritis, duodenal ulcers, and gastric cancer (each containing two strains) at 4 h. In addition, we investigated the time-course expression of fucosyltransferase (FUT) 1–6 genes in GES-1 cells stimulated with H. pylori strains at 0.5–8 h. At 4 h post-infection, Lotus, AAA, BC2LCN, PA-IIL, CNL and ACG lectins had increased signals in H. pylori-infected GES-1 cells compared to uninfected cells. Higher expression of FUT1 and FUT2 was detected in all H. pylori-infected GES-1 cells within 2 h, regardless of the H. pylori strain. In particular, the expression of FUT2 was higher in H. pylori-infected GES-1 cells with a higher fold change in levels of BC2LCN lectin specific to α1-2 linked fucose (Fuc) at 4 h. The results suggest that the high levels of α1, 2-linked Fuc synthesized by FUT1/2, might play a role in the preliminary stage of H. pylori infection. This provides us with pivotal information to understand the adhesion of H. pylori to human gastric epithelial cells.


2021 ◽  
Vol 10 (13) ◽  
pp. 2755
Author(s):  
Nabil Gastli ◽  
Margaux Allain ◽  
Dominique Lamarque ◽  
Vered Abitbol ◽  
Annick Billoët ◽  
...  

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.


Background and aim: Helicobacter pylori (H. pylori) is an incriminated pathogen causing diseases in both animals and humans and considered a zoonotic pathogen. H. pylori infection is considered a cause of gastric cancer, which rests a significant health care challenge. This study analyzes the expression pattern of matrix metalloprotein 2 (MMP-2) in patients with Helicobacter pylori-associated gastritis and the effect of H. pylori on gastric cancer stem cells, as well as study the role of helicon bacteriosis in dog in transmission of H. pylori infection to human. Materials and methods: Fifty-five of each sample (gastric biopsy, blood and stool) were collected from patients suffering from dyspepsia, chronic vomiting and perforated peptic ulcers and also from apparent healthy dogs. The investigation detected H. pylori by serological and histopathological examination. Biopsies were stored in physiological saline for identification of H. pylori by conventional time PCR. MMP-2 and Gastric cancer stem cells were then identified by immunohistochemistry. Results: Serological identification for H. pylori Antigen and Antibodies revealed (63% human, 50% dogs) and (87% human, 90% dogs) respectively were positive. Genotyping of H. pylori based on 16S rRNA gene showed 54.5% of human and 35% of dogs were positive. Immunohistochemistry revealed strong expression of CD44 in H. pylori- associated gastric cancer cases, MMP-2 expression was observed in all neoplastic lesions associated with H. pylori infection. Conclusion: H. pylori infection affects gastric mucosa and induces changes in gastric stem cells altering their differentiation and increased expression of MMP’s and CD44with a resultant potentiation of oncogenic alteration. In addition the up-regulation of both markers could be an instrumental to interpret the origination of gastric cancer.


2019 ◽  
Vol 77 (9) ◽  
Author(s):  
Narges Dastmalchi ◽  
Seyed Mahdi Banan Khojasteh ◽  
Mirsaed Miri Nargesi ◽  
Reza Safaralizadeh

ABSTRACT Helicobacter pylori infection performs a key role in gastric tumorigenesis. Long non-coding RNAs (lncRNAs) have demonstrated a great potential to be regarded as effective malignancy biomarkers for various gastrointestinal diseases including gastric cancer (GC). The present review highlights the relationship between lncRNAs and H. pylori in GC. Several studies have examined not only the involvement of lncRNAs in H. pylori-associated GC progression but also their molecular mechanisms of action. Among the pertinent studies, some have addressed the effects of H. pylori infection on modulatory networks of lncRNAs, while others have evaluated the effects of changes in the expression level of lncRNAs in H. pylori-associated gastric diseases, especially GC. The relationship between lncRNAs and H. pylori was found to be modulated by various molecular pathways.


2021 ◽  
Vol 22 (9) ◽  
pp. 4823
Author(s):  
María Fernanda González ◽  
Paula Díaz ◽  
Alejandra Sandoval-Bórquez ◽  
Daniela Herrera ◽  
Andrew F. G. Quest

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 181
Author(s):  
Masami Suganuma ◽  
Tatsuro Watanabe ◽  
Eisaburo Sueoka ◽  
In Kyoung Lim ◽  
Hirota Fujiki

The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.


Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhijing Xue ◽  
Yuanhai You ◽  
Lihua He ◽  
Yanan Gong ◽  
Lu Sun ◽  
...  

Abstract Background The cytotoxin-associated gene A (cagA) is one of the most important virulence factors of Helicobacter pylori (H. pylori). There is a highly polymorphic Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region in the C-terminal of CagA protein. This repeat region is thought to play an important role in the pathogenesis of gastrointestinal diseases. The aim of this study was to investigate the diversity of cagA 3′ variable region and the amino acid polymorphisms in the EPIYA segments of the CagA C-terminal region of H. pylori, and their association with gastroduodenal diseases. Methods A total of 515 H. pylori strains from patients in 14 different geographical regions of China were collected. The genomic DNA from each strain was extracted and the cagA 3′ variable region was amplified by polymerase chain reaction (PCR). The PCR products were sequenced and analyzed using MEGA 7.0 software. Results A total of 503 (97.7%) H. pylori strains were cagA-positive and 1,587 EPIYA motifs were identified, including 12 types of EPIYA or EPIYA-like sequences. In addition to the four reported major segments, several rare segments (e.g., B′, B″ and D′) were defined and 20 different sequence types (e.g., ABD, ABC) were found in our study. A total of 481 (95.6%) strains carried the East Asian type CagA, and the ABD subtypes were most prevalent (82.1%). Only 22 strains carried the Western type CagA, which included AC, ABC, ABCC and ABCCCC subtypes. The CagA-ABD subtype had statistical difference in different geographical regions (P = 0.006). There were seven amino acid polymorphisms in the sequences surrounding the EPIYA motifs, among which amino acids 893 and 894 had a statistical difference with gastric cancer (P = 0.004). Conclusions In this study, 503 CagA sequences were studied and analyzed in depth. In Chinese population, most H. pylori strains were of the CagA-ABD subtype and its presence was associated with gastroduodenal diseases. Amino acid polymorphisms at residues 893 and 894 flanking the EPIYA motifs had a statistically significant association with gastric cancer.


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