694 Cytotoxin-associated gene-A bearing strains of Helicobacter pylori and atrial fibrillation due to ischaemic origin. Is there a link?

2007 ◽  
Vol 6 (1) ◽  
pp. 152-152
Author(s):  
H BADRAN ◽  
M MAHFOUZ
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Asieh Bolandi ◽  
Saam Torkan ◽  
Iman Alavi

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.


2018 ◽  
Vol 19 (10) ◽  
pp. 3273 ◽  
Author(s):  
Cindy Ulloa-Guerrero ◽  
Maria Delgado ◽  
Carlos Jaramillo

Helicobacter pylori cytotoxin-associated gene A protein (CagA) has been associated with the increase in virulence and risk of cancer. It has been demonstrated that CagA’s translocation is dependent on its interaction with phosphatidylserine. We evaluated the variability of the N-terminal CagA in 127 sequences reported in NCBI, by referring to molecular interaction forces with the phosphatidylserine and the docking of three mutations chosen from variations in specific positions. The major sites of conservation of the residues involved in CagA–Phosphatidylserine interaction were 617, 621 and 626 which had no amino acid variation. Position 636 had the lowest conservation score; mutations in this position were evaluated to observe the differences in intermolecular forces for the CagA–Phosphatidylserine complex. We evaluated the docking of three mutations: K636A, K636R and K636N. The crystal and mutation models presented a ΔG of −8.919907, −8.665261, −8.701923, −8.515097 Kcal/mol, respectively, while mutations K636A, K636R, K636N and the crystal structure presented 0, 3, 4 and 1 H-bonds, respectively. Likewise, the bulk effect of the ΔG and amount of H-bonds was estimated in all of the docking models. The type of mutation affected both the ΔG ( χ 2 ( 1 ) = 93.82 , p-value < 2.2 × 10 − 16 ) and the H-bonds ( χ 2 ( 1 ) = 91.93 , p-value < 2.2 × 10 − 16 ). Overall, 76.9% of the strains that exhibit the K636N mutation produced a severe pathology. The average H-bond count diminished when comparing the mutations with the crystal structure of all the docking models, which means that other molecular forces are involved in the CagA–Phosphatidylserine complex interaction.


Author(s):  
Hazim Abdul Rahman Alhit

Editorial: Helicobacter pylori is a micro-aerophilic, helical-form gramnegative aggressive bacteria. Accordingly, the idiom “Helico” intimates its helical appearance, “bacter” symbolizes bacteria, while “pylori” denotes stomach due to the first and common site of this bacteria living. Further, Marshall B. and Warren R. observed and described it in 1982. Then, the followed investigators studied this bacterium in detail with its consequences and complexities [1]. Gastric upset (Indigestion), dyspepsia: means impaired gastric digestion. Accordingly, the patient complains of upper abdominal pain, heartburn, belching, nausea, even feeling earlier gastric fullness than expected while eating. Furthermore, there are many causes of indigestion like gastroesophageal reflux disease, ulcer disease, gastritis, and even gastric cancer. Hence, unexplained recent onset dyspepsia in older people may need additional examinations. Moreover, one of the common causes is Helicobacter pylori infection, which needs laboratory and endoscopic examination [2]. Argument Many theories investigated the etiology and pathogenesis of Helicobacter pylori infection, concerning chronic or acute gastritis. Hence, gastric upset is the main presentation of both types of gastritis. Evidences The genotype is valuable in determining the dominant Helicobacter pylori strains as the isolates were different genetically plus heterogeneous distribution. Accordingly, the vac and cag markers operate a significant function in defining clinical consequences. These virulence agents are present in a subset of Helicobacter pylori strains isolates like cagA, iceA, vacA, and ureC. Moreover, the cagA causes cytotoxins induction by the gastric epithelial cell as Interleukin 8 [3]. The molecular intercommunication researches exhibit that the act of acarus calamus in hindering biofilm formation in Helicobacter pylori is due to the inhibitory impact of phytobio-active component, β-sitosterol, on the quorum sensing molecules-ToxB, PhnB, DnaA, plus Sip. Consequently, this opinion may suggest the molecular mechanism of Helicobacter pylori in producing the acidrelated complaints and gives a clue to a new therapy [4]. Helicobacter pylori infection causes lncRNA risk impression linked to H. pylori in gastric cancer patients and can prognosticate the prediction of these patients [5]. There was a close relationship between raised serum IgE levels in Helicobacter pylori infected patients [6]. Counterargument The laboratory investigations of Helicobacter pylori infection depend on several factors like the fluctuations of serum antibody titers in a time series, the antigene detection in stool tests, the false-positive results of lab tests, or the manner of endoscopic biopsy collection. Furthermore, other factors like the variations in Cytotoxin-Associated Gene A (CagA) in East Asian patients. Moreover, the gastric nodularity or atrophy, the patient’s age, the severity of the gastric mucosal infection are causes of variations in Helicobacter pylori detection at the time of the investigation [7]. Refutation The significant markers of H. pylori, the presence of the vacuolating cytotoxin (vacA), the cytotoxin-associated gene A (cagA), which induced by the direct communication with gastric epithelium factor antigen (iceA gene), and the presence of urease C gene (ureC). Consequently, all these factors play the principal factors in deciding the gastric consequences of Helicobacter infections. Conclusion Helicobacter pylori induce gastric upset by several mechanisms to form numerous Gastric diseases.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 1055 ◽  
Author(s):  
Jacek Baj ◽  
Izabela Korona-Głowniak ◽  
Alicja Forma ◽  
Amr Maani ◽  
Elżbieta Sitarz ◽  
...  

Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world’s population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial–mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial–mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer.


2019 ◽  
Vol 147 ◽  
Author(s):  
K. Muhsen ◽  
R. Sinnereich ◽  
G. Beer-Davidson ◽  
H. Nassar ◽  
W. Abu Ahmed ◽  
...  

Abstract We examined the prevalence and correlates of Helicobacter pylori (H. pylori) infection according to cytotoxin-associated gene A (CagA) phenotype, a main virulence antigen, among the ethnically diverse population groups of Jerusalem. A cross-sectional study was undertaken in Arab (N = 959) and Jewish (N = 692) adults, randomly selected from Israel's national population registry in age-sex and population strata. Sera were tested for H. pylori immunoglobulin G (IgG) antibodies. Positive samples were tested for virulence IgG antibodies to recombinant CagA protein, by enzyme-linked immunosorbent assay. Multinomial regression models were fitted to examine associations of sociodemographic factors with H. pylori phenotypes. H. pylori IgG antibody sero-prevalence was 83.3% (95% confidence interval (CI) 80.0%–85.5%) and 61.4% (95% CI 57.7%–65.0%) among Arabs and Jews, respectively. Among H. pylori positives, the respective CagA IgG antibody sero-positivity was 42.3% (95% CI 38.9%–45.8%) and 32.5% (95% CI 28.2%–37.1%). Among Jews, being born in the Former Soviet Union, the Middle East and North Africa, vs. Israel and the Americas, was positively associated with CagA sero-positivity. In both populations, sibship size was positively associated with both CagA positive and negative phenotypes; and education was inversely associated. In conclusion, CagA positive and negative infection had similar correlates, suggesting shared sources of these two H. pylori phenotypes.


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