scholarly journals Campylobacter and helicobacter in the etiology of gastrointestinal diseases

2012 ◽  
Vol 64 (4) ◽  
pp. 1389-1404 ◽  
Author(s):  
Biljana Miljkovic-Selimovic ◽  
Branislava Kocic ◽  
Tatjana Babic
Keyword(s):  
Bacterial Genome ◽  
Optimal Growth ◽  
The Elderly ◽  
Distinct Species ◽  
Gastrointestinal Diseases ◽  
Human Pathogens ◽  
Endotoxin Activity ◽  
Clinical Presentations ◽  
Human Disorders ◽  
H Pylori

The order Campylobacterales comprises two genera: Campylobacter and Helicobacter, with a widespread distribution in both humans and animals. They are Gram-negative, spiral, helical and microaerophilic bacteria, with an optimal growth temperature of 37?C for H. pylori and 42?C for C. jejuni strains. While Helicobacter pylori are restricted to humans, other helicobacter species can be found in different mammals and occasionally in humans. Several Campylobacter species are recognized as human pathogens, while distinct species are pathogenic only occasionally, in children, the elderly and immunocompromised patients. Campylobacters and helicobacters are well adapted to the living conditions inside the gastrointestinal tract, where they can cause diseases as a consequence of inflammation. In addition, they are related to certain extraintestinal diseases, post-infectious sequels, malignancy and autoimmunity. Different clinical presentations of human disorders may be the consequences of the diversity in host immune response, bacterial genome, endotoxin activity as well as specific bacterial virulence factors.

scholarly journals Pathogenesis of Helicobacter pylori Infection

2006 ◽  
Vol 19 (3) ◽  
pp. 449-490 ◽  
Author(s):  
Johannes G. Kusters ◽  
Arnoud H. M. van Vliet ◽  
Ernst J. Kuipers
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Clinical Symptoms ◽  
Gastrointestinal Diseases ◽  
Immune Gene ◽  
Human Pathogens ◽  
Vacuolating Cytotoxin ◽  
Chronic Active Gastritis ◽  
Key Factor ◽  
H Pylori

SUMMARY Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.

scholarly journals The correlation between lncRNAs and Helicobacter pylori in gastric cancer

2019 ◽  
Vol 77 (9) ◽  
Author(s):  
Narges Dastmalchi ◽  
Seyed Mahdi Banan Khojasteh ◽  
Mirsaed Miri Nargesi ◽  
Reza Safaralizadeh
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Molecular Mechanisms ◽  
Gastrointestinal Diseases ◽  
Mechanisms Of Action ◽  
Molecular Pathways ◽  
Gastric Diseases ◽  
Non Coding Rnas ◽  
H Pylori ◽  
The Relationship

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.

scholarly journals Serodiagnosis and Bacterial Genome of Helicobacter pylori Infection

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 467
Author(s):  
Aina Ichihara ◽  
Hinako Ojima ◽  
Kazuyoshi Gotoh ◽  
Osamu Matsushita ◽  
Susumu Take ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibody Titer ◽  
Bacterial Genome ◽  
Serum Antibody ◽  
Gene Mutations ◽  
Bacterial Genomes ◽  
Western Blots ◽  
A Genome ◽  
Vaca Gene ◽  
H Pylori

The infection caused by Helicobacter pylori is associated with several diseases, including gastric cancer. Several methods for the diagnosis of H. pylori infection exist, including endoscopy, the urea breath test, and the fecal antigen test, which is the serum antibody titer test that is often used since it is a simple and highly sensitive test. In this context, this study aims to find the association between different antibody reactivities and the organization of bacterial genomes. Next-generation sequences were performed to determine the genome sequences of four strains of antigens with different reactivity. The search was performed on the common genes, with the homology analysis conducted using a genome ring and dot plot analysis. The two antigens of the highly reactive strains showed a high gene homology, and Western blots for CagA and VacA also showed high expression levels of proteins. In the poorly responsive antigen strains, it was found that the inversion occurred around the vacA gene in the genome. The structure of bacterial genomes might contribute to the poor reactivity exhibited by the antibodies of patients. In the future, an accurate serodiagnosis could be performed by using a strain with few gene mutations of the antigen used for the antibody titer test of H. pylori.

scholarly journals PREVALENCE OF INFECTION WITH CAGA-POSITIVE HELICOBACTER PYLORI STRAINS AMONG CHILDREN AND ADOLESCENTS IN SOUTHERN BRAZIL

2014 ◽  
Vol 51 (3) ◽  
pp. 180-185 ◽  
Author(s):  
Juliana Ghisleni de OLIVEIRA ◽  
Cristina Helena Targa FERREIRA ◽  
Anna Carolina Saraiva CAMERIN ◽  
Cláudia Augustin ROTA ◽  
Luíse MEURER ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Children And Adolescents ◽  
Polymerase Chain Reaction Method ◽  
Southern Brazil ◽  
Worldwide Distribution ◽  
Clinical Presentations ◽  
Urease Test ◽  
Polymerase Chain ◽  
H Pylori ◽  
Low Prevalence

Context Helicobacter pylori (H. pylori) has a worldwide distribution, but the prevalence of infection, virulence factors, and clinical presentation vary widely according to the studied population. In Brazil, a continental country composed of several ethnicities and cultural habits, the behavior of infection also appears to vary, as many other studies have shown. Objectives Describe the prevalence of infection with cagA-positive H. pylori strains in a group of children and adolescents who underwent esophagogastroduodenoscopy in Porto Alegre, Rio Grande do Sul. Methods Fifty-four gastric biopsy specimens of children and adolescents with H. pylori infection demonstrated by histology, urease test and molecular analysis were tested for the presence of cagA positive H. pylori strains by the polymerase chain reaction method. Results he prevalence of cagA-positive H. pylori was 29.6% (95% confidence interval, 18 to 43.6%). There were no statistically significant differences in clinical or demographic characteristics or in the endoscopic and histological features of patients infected with cagA-positive strains as compared with those infected by cagA-negative strains. Conclusions he study showed a low prevalence of infection with cagA-positive H. pylori strains among children and adolescents who underwent EGD in southern Brazil, in comparison to studies conducted with children from other regions of Brazil. There was no association between the presence of cagA-positive strains and more severe clinical presentations in the studied sample.

Vonoprozan: potentially new first-line treatment for delayed upper gastrointestinal bleeds following endoscopic procedures? A letter to the editor

2022 ◽  
Vol 71 (12) ◽  
pp. 2838-2838
Author(s):  
Muhammad Umer ◽  
Syed Wasif Bukhari
Keyword(s):  
Endoscopic Submucosal Dissection ◽  
Gastrointestinal Diseases ◽  
High Dose ◽  
First Line ◽  
Gastroesophageal Varices ◽  
Delayed Bleeding ◽  
Submucosal Dissection ◽  
Significant Difference ◽  
H Pylori ◽  
Line Of Therapy

Endoscopy nowadays is widely used as a diagnostic and therapeutic tool for various gastrointestinal diseases due to it being less invasive and safer. However, amongst some adverse events is delayed bleeding. The definition of delayed bleeding requires endoscopic hemostasis and/or blood transfusion after at least two days of treatment. (1) Oesophageal cancer is comparatively more common in Pakistan, being 7th most common malignancy in men and 6th most common in women in Karachi. (2) Oesophageal endoscopic submucosal dissection (E-ESD) employed in the treatment of the above- mentioned cancer has an incidence of delayed bleeding of about 1.3-6.7%. (1) The prevalence of gastric cancer across Pakistan was about 2-18% (3), for which endoscopic submucosal dissection is often used has an incidence of delayed bleeding of 4.7-15.6%. (1) Endoscopic therapy for gastroesophageal varices can also result in delayed bleeding, the incidence of which easily reaches up to 10%. (1) In a retrospective cohort study of 124,422 patients conducted in Japan, it was found that vonoprazan was more effective in reducing the risk of delayed bleeding compared to omeprazole. (OR= 0.75) (1) Vonoprazan works by competitively inhibiting the potassium-acid channel resulting in strong and sustained acid inhibition. (4) It was also found to have a superior effect in the eradication of H Pylori and an equal effect in acid-related disorders. (5)  In the retrospective study mentioned above, it is also worth noting that the efficacy of vonoprazan was variable with respect to procedures and was most prominent with gastroduodenal endoscopic submucosal dissection (OR=0.70). (1) Other procedures did not elicit any significant difference. In addition, standard/high dose vonoprazan proved to be most efficacious in reducing the risk of delayed bleeding compared with standard/high-dose PPI and low-dose vonoprazan. It was also observed that patients taking anti-thrombotic medications at a higher risk of delayed bleeding also benefited from high-dose vonoprazan. (OR=0.74) (1) The findings above compel the conclusion that high dose vonoprazan should be ideal for reducing the risk of delayed bleeding in patients who have undergone gastroduodenal endoscopic submucosal dissection and/or are on anti-thrombotics. Though high-dose vonoprazan does look promising, it is imperative that more randomized controlled trials on more diverse populations be conducted to further explore its efficacy and safety as the drug might be a potential first line of therapy.

scholarly journals Nutrition and Healthy Aging: Prevention and Treatment of Gastrointestinal Diseases

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4337
Author(s):  
Neri Maria Cristina ◽  
d’Alba Lucia
Keyword(s):  
Quality Of Life ◽  
Elderly People ◽  
Healthy Aging ◽  
Well Being ◽  
The Elderly ◽  
Gastrointestinal Diseases ◽  
The Body ◽  
Fundamental Aspect ◽  
Effective Prevention

Nutritional well-being is a fundamental aspect for the health, autonomy and, therefore, the quality of life of all people, but especially of the elderly. It is estimated that at least half of non-institutionalized elderly people need nutritional intervention to improve their health and that 85% have one or more chronic diseases that could improve with correct nutrition. Although prevalence estimates are highly variable, depending on the population considered and the tool used for its assessment, malnutrition in the elderly has been reported up to 50%. Older patients are particularly at risk of malnutrition, due to multiple etiopathogenetic factors which can lead to a reduction or utilization in the intake of nutrients, a progressive loss of functional autonomy with dependence on food, and psychological problems related to economic or social isolation, e.g., linked to poverty or loneliness. Changes in the aging gut involve the mechanical disintegration of food, gastrointestinal motor function, food transit, intestinal wall function, and chemical digestion of food. These alterations progressively lead to the reduced ability to supply the body with adequate levels of nutrients, with the consequent development of malnutrition. Furthermore, studies have shown that the quality of life is impaired both in gastrointestinal diseases, but especially in malnutrition. A better understanding of the pathophysiology of malnutrition in elderly people is necessary to promote the knowledge of age-related changes in appetite, food intake, homeostasis, and body composition in order to better develop effective prevention and intervention strategies to achieve healthy aging.

scholarly journals Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 759
Author(s):  
Monika Maria Biernat ◽  
Aldona Bińkowska ◽  
Łukasz Łaczmański ◽  
Paweł Biernat ◽  
Paweł Krzyżek ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Point Mutations ◽  
Gastrointestinal Diseases ◽  
Drug Susceptibility Testing ◽  
Test Method ◽  
Ulcer Disease ◽  
Genotypic Analysis ◽  
Clinical Diagnoses ◽  
H Pylori

Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.

scholarly journals Vitamin B6 Is Required for Full Motility and Virulence in Helicobacter pylori

mBio ◽  
2010 ◽  
Vol 1 (3) ◽  
Author(s):  
Alexandra Grubman ◽  
Alexandra Phillips ◽  
Marie Thibonnier ◽  
Maria Kaparakis-Liaskos ◽  
Chad Johnson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Bacterial Pathogens ◽  
Therapeutic Targets ◽  
Vitamin B ◽  
Human Pathogens ◽  
Chronic Colonization ◽  
H Pylori

ABSTRACTDespite recent advances in our understanding of howHelicobacter pyloricauses disease, the factors that allow this pathogen to persist in the stomach have not yet been fully characterized. To identify new virulence factors inH. pylori, we generated low-infectivity variants of a mouse-colonizingH. pyloristrain using the classical technique ofin vitroattenuation. The resulting variants and their highly infectious progenitor bacteria were then analyzed by global gene expression profiling. The gene expression levels of five open reading frames (ORFs) were significantly reduced in low-infectivity variants, with the most significant changes observed for ORFs HP1583 and HP1582. These ORFs were annotated as encoding homologs of theEscherichia colivitamin B6biosynthesis enzymes PdxA and PdxJ. Functional complementation studies withE. coliconfirmedH. pyloriPdxA and PdxJ to bebona fidehomologs of vitamin B6biosynthesis enzymes. Importantly,H. pyloriPdxA was required for optimal growthin vitroand was shown to be essential for chronic colonization in mice. In addition to having a well-known metabolic role, vitamin B6is necessary for the synthesis of glycosylated flagella and for flagellum-based motility inH. pylori. Thus, for the first time, we identify vitamin B6biosynthesis enzymes as novel virulence factors in bacteria. Interestingly,pdxAandpdxJorthologs are present in a number of human pathogens, but not in mammalian cells. We therefore propose that PdxA/J enzymes may represent ideal candidates for therapeutic targets against bacterial pathogens.IMPORTANCEApproximately half of the world’s population is infected withH. pylori, yet howH. pyloribacteria establish chronic infections in human hosts remains elusive. From gene array studies, we identified two genes as representing potentially novel colonization factors forH. pylori. These genes encoded enzymes involved in the synthesis of vitamin B6, an important molecule for many metabolic reactions in living organisms. Little is currently known regarding vitamin B6biosynthesis in human pathogens. We showed that mutantH. pyloribacteria lacking an enzyme involved inde novovitamin B6biosynthesis, PdxA, were unable to synthesize motility appendages (flagella) and were unable to establish chronic colonization in mice. Thus, this work identifies vitamin B6biosynthesis enzymes as novel virulence factors for bacterial pathogens. Interestingly, a number of human pathogens, but not their mammalian hosts, possess these genes, which suggests that Pdx enzymes may represent ideal candidates for new therapeutic targets.

scholarly journals Relationship between Helicobacter pylori iceA, cagA, and vacA Status and Clinical Outcome: Studies in Four Different Countries

1999 ◽  
Vol 37 (7) ◽  
pp. 2274-2279 ◽  
Author(s):  
Yoshio Yamaoka ◽  
Tadashi Kodama ◽  
Oscar Gutierrez ◽  
Jong G. Kim ◽  
Kei Kashima ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Clinical Outcome ◽  
Clinical Presentation ◽  
The United States ◽  
Peptic Ulcers ◽  
Predominant Genotype ◽  
Clinical Presentations ◽  
Geographic Differences ◽  
H Pylori

There is continuing interest in identifying Helicobacter pylori virulence factors that might predict the risk for symptomatic clinical outcomes. It has been proposed thaticeA and cagA genes are such markers and can identify patients with peptic ulcers. We compared H. pylori isolates from four countries, looking at thecagA and vacA genotypes, iceAalleles, and presentation of the infection. We used PCR to examineiceA, vacA, and cagA status of 424H. pylori isolates obtained from patients with different clinical presentations (peptic ulcer, gastric cancer, and atrophic gastritis). The H. pylori isolates examined included 107 strains from Bogota, Colombia, 70 from Houston, Tex., 135 from Seoul, Korea, and 112 from Kyoto, Japan. The predominant genotype differed among countries: the cagA-positive iceA1 vacA s1c-m1 genotype was predominant in Japan and Korea, thecagA-positive iceA2 vacA s1b-m1 genotype was predominant in the United States, and the cagA-positiveiceA2 vacA s1a-m1 genotype was predominant in Colombia. There was no association between the iceA,vacA, or cagA status and clinical outcome in patients in the countries studied. iceA status shows considerable geographic differences, and neither iceA nor combinations of iceA, vacA, andcagA were helpful in predicting the clinical presentation of an H. pylori infection.

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