scholarly journals Helicobacter pylori virulence factors: relationship between genetic variability and phylogeographic origin

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12272
Author(s):  
Aura M. Rodriguez ◽  
Daniel A. Urrea ◽  
Carlos F. Prada
Keyword(s):  
Helicobacter Pylori ◽  
Genetic Variability ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Gene Annotation ◽  
Gastric Lymphoma ◽  
High Rate ◽  
Peptic Ulcers ◽  
Bioinformatics Analyses ◽  
High Genetic Diversity

Background Helicobacter pylori is a pathogenic bacteria that colonize the gastrointestinal tract from human stomachs and causes diseases including gastritis, peptic ulcers, gastric lymphoma (MALT), and gastric cancer, with a higher prevalence in developing countries. Its high genetic diversity among strains is caused by a high mutation rate, observing virulence factors (VFs) variations in different geographic lineages. This study aimed to postulate the genetic variability associated with virulence factors present in the Helicobacter pylori strains, to identify the relationship of these genes with their phylogeographic origin. Methods The complete genomes of 135 strains available in NCBI, from different population origins, were analyzed using bioinformatics tools, identifying a high rate; as well as reorganization events in 87 virulence factor genes, divided into seven functional groups, to determine changes in position, number of copies, nucleotide identity and size, contrasting them with their geographical lineage and pathogenic phenotype. Results Bioinformatics analyses show a high rate of gene annotation errors in VF. Analysis of genetic variability of VFs shown that there is not a direct relationship between the reorganization and geographic lineage. However, regarding the pathogenic phenotype demonstrated in the analysis of many copies, size, and similarity when dividing the strains that possess and not the cag pathogenicity island (cagPAI), having a higher risk of developing gastritis and peptic ulcer was evidenced. Our data has shown that the analysis of the overall genetic variability of all VFs present in each strain of H. pylori is key information in understanding its pathogenic behavior.

scholarly journals Prevalence of vacA, cagA, and iceA Virulence Factors of Helicobacter Pylori Isolated from Gastro-duodenal Patients

2020 ◽  
Vol 14 (1) ◽  
pp. 72-79
Author(s):  
Ahmed Husham Salman ◽  
Aumed Arshad Hawezy
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Gastric Lymphoma ◽  
Signs And Symptoms ◽  
Molecular Technique ◽  
Peptic Ulcers ◽  
Back Ground ◽  
H Pylori ◽  
Pcr Test

Back ground: Helicobacter pylori are bacteria colonize in the human epithelial cells of the gastrointestinal tract. Its infection causes different diseases, including chronic gastritis, peptic ulcers, gastric lymphoma and adenocarcinoma. H. pylori have many virulence factors attributing in one or more biological functions. Objective: Detecting the prevalence of virulence factor genes vacA, cagA, iceA among strain of H. pylori using molecular technique (PCR). Materials and methods: Sixty patients (27 male and 33 female), aged 18 and above included in the present study who showed signs and symptoms of H. pylori, and undergo endoscopy between period of November 2019 and February 2020. RUT and PCR test done to detect the presence of H. pylori infection, also PCR used to detect the three virulence factors. Results: Result showed that 44 patients, 21 (47.7%) male and 23 (52.3%) female were detected as positive H. pylori infections, among them 13 (29.5%) above 50 years, and 31 (70.4%) were below 50 years. While prevalence of the virulence factors vacA, cagA, and iceA were (100%), (84.1%), and (34.1%) respectively. Conclusion: It can be concluded that the frequency and prevalence of these genes are differed and showed significant differences among them. Also, PCR test is sensitive and accurate for detection of H. pylori virulence genes.

scholarly journals Use of PCR and culture to detect Helicobacter pylori in naturally infected cats following triple antimicrobial therapy.

1996 ◽  
Vol 40 (6) ◽  
pp. 1486-1490 ◽  
Author(s):  
S E Perkins ◽  
L L Yan ◽  
Z Shen ◽  
A Hayward ◽  
J C Murphy ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Juice ◽  
Antimicrobial Therapy ◽  
Developed Countries ◽  
Gastric Fluid ◽  
High Rate ◽  
Pcr Analysis ◽  
Human Populations ◽  
Peptic Ulcers ◽  
H Pylori

Helicobacter pylori causes gastritis and peptic ulcers and is linked to gastric cancer. Domestic cats from a commercial source were found to be naturally infected with H. pylori, and studies were undertaken to eradicate H. pylori from infected cats by using triple antimicrobial therapy. Eight cats infected with H. pylori were used in the study. Six cats received a 21-day course of oral amoxicillin, metronidazole, and omeprazole, and two cats served as controls. Two weeks and 4 weeks posttreatment (p.t.), all six treated cats were negative at several sites (saliva, gastric juice, and gastric mucosa) for H. pylori by culture. However, as determined by PCR with primers specific for the 26-kDa product, the majority of cats at 2 and 4 weeks p.t. had gastric fluid samples which were positive for H. pylori and three of three cats at 2 weeks p.t. had dental plaque which was positive for H. pylori. At 6 weeks p.t., all six cats had H. pylori-negative cultures for samples from several gastric sites taken at necropsy, and only one cat had H. pylori cultured from gastric juice. PCR analysis revealed that five of six cats had H. pylori DNA amplification products from plaque, saliva, and/or gastric fluid samples. Negative bacterial cultures for cats for which there was demonstrable PCR amplification of H. pylori DNA may reflect the inability of in vitro culture techniques to isolate small numbers of H. pylori organisms, focal colonization at sites not cultured, or a failure of the antibiotics to successfully eradicate H. pylori from extragastric sites which allowed subsequent recolonization of the stomach after cessation of therapy. Alternatively, the treatment strategy may have induced in vivo viable but nonculturable coccoid forms of H. pylori. The H. pylori cat model should allow further studies to test these hypotheses as well as the efficacies of other combined therapeutic regimens. Also, because 100% of these cats were naturally infected with H.pylori, this model should prove useful in exploring mechanisms whereby human populations in underdeveloped countries, which have H. pylori infection rates approaching 100%, have a high rate of recurrence of H. pylori infection after use of prescribed antibiotic therapies that successfully eradicate H. pylori in individuals in developed countries.

scholarly journals Evaluation of the Association of Nine Helicobacter pylori Virulence Factors with Strains Involved in Low-Grade Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

2004 ◽  
Vol 72 (2) ◽  
pp. 880-888 ◽  
Author(s):  
Philippe Lehours ◽  
Armelle Ménard ◽  
Sandrine Dupouy ◽  
Bernard Bergey ◽  
Fréderique Richy ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Virulence Factors ◽  
Malt Lymphoma ◽  
Lymphoid Tissue ◽  
Gastric Lymphoma ◽  
Gastric Malt Lymphoma ◽  
Low Grade ◽  
H Pylori ◽  
Few Data

ABSTRACT Helicobacter pylori has been associated with the development of two malignant diseases: gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Although the cag pathogenicity island, especially the cagA gene, has been linked with adenocarcinoma, few data concerning H. pylori pathogenic factors involved in low-grade gastric MALT lymphoma are available. The goal of this study was to analyze the prevalence of and correlation between genes coding for seven H. pylori virulence factors (cagA, cagE, vacA, iceA, babA, hopQ, and oipA) and two novel adhesins (sabA and hopZ) by comparing a collection of 43 H. pylori strains isolated from patients with low-grade gastric MALT lymphoma to 39 strains isolated from age-matched patients with gastritis only. Our results show that taken individually, none of the nine genes tested can be considered associated with MALT strains and allow us to conclude that MALT pathogenesis is not linked with more proinflammatory H. pylori strains. We demonstrated that in patients infected with strains harboring the iceA1 allele, sabA functional status, and hopZ “off” status, the odds of developing a MALT lymphoma were 10 times higher. However, the low prevalence of such strains (10 of 43 MALT strains) renders this triple association a low-sensitivity marker for MALT strains. Our data confirmed that H. pylori virulence factors are correlated with one another. If the involvement of H. pylori in MALT lymphoma is well established, the pathomechanism by which gastric lymphoma occurs remains to be identified.

scholarly journals VARIABILITY OF NEUTROPHIL-ACTIVATING PROTEIN AMONG HELICOBACTER PYLORI STRAINS

2021 ◽  
Vol 80 (1) ◽  
pp. 43-50
Author(s):  
Cecília R.C. Calado
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Immune System ◽  
Virulence Factors ◽  
Immunomodulatory Activity ◽  
Host Immune System ◽  
High Genetic Diversity ◽  
Vacuolating Cytotoxin ◽  
Synonymous Substitutions ◽  
H Pylori

The Helicobacter pylori neutrophil activating protein (NAP) presents relevant inflammatory and immunomodulatory activity and has consequently been explored as a diagnosis and therapeutic target. In the present work, nap gene sequences, retrieved from H. pylori isolated world-wide, were analyzed, a high genetic diversity (with 88% of alleles) being observed in accordance with other virulence factors. The phylogenetic analysis did not reveal the separation of strains per geographical region according to a bacterial panmictic population. When compared to other genes of virulence factors of H. pylori, such as the vacuolating cytotoxin A (vacA), nap presents slightly lower genetic variability, concerning the number of alleles and polymorphic sites, pointing to a possible lower pressure of the host immune system. The nap genetic diversity is associated to a high proportion of synonymous substitutions in relation to non-synonymous substitutions, pointing to equilibrium between the need for antigenic diversity as a mechanism to escape the host immune system and the maintenance of the proteins function. All this information could be put to good use when planning the NAP application as a therapeutic or diagnostic target.

scholarly journals Antichelicobacter therapy in the context of increasing bacterial resistance

2021 ◽  
pp. 24-27
Author(s):  
Ya. V. Korost ◽  
N. M. Gorobets
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Gastrointestinal Tract ◽  
Bacterial Resistance ◽  
Gastric Lymphoma ◽  
Pathological Process ◽  
Peptic Ulcers ◽  
Cancer Of The Stomach ◽  
Main Components ◽  
Further Development

A modern strategy for the treatment of diseases associated with Helicobacter pylori is the mandatory inclusion in the scheme of treatment of antibiotics, as well as considering the level of bacterial resistance to the main components of therapy. In Ukraine, Helicobacter pylori infection in some areas can reach about 80%, so the prevalence of peptic ulcer, atrophic gastritis and other diseases of the gastrointestinal tract is extremely high in all sections of the population. Topical for our country is the use of standard triple antyhelicobacter therapy, which includes: proton pump inhibitor in combination with clarithromycin + amoxicillin. Such therapy lasting 10 or 14 days allows to completely free the gastrointestinal tract from Helicobacter pylori, and to prevent the further development of pathological process on the mucous membrane. This tactic can successfully prevent the growth of incidence of gastric lymphoma, cancer of the stomach, as well as reduce the likelihood of complications in peptic ulcers.

EFFICACY OF MODIFIED BISMUTH QUADRUPLE THERAPY (RBMA) AS FIRST-LINE THERAPY FOR ERADICATION OF HELICOBACTER PYLORI IN PATIENTS WITH CHRONIC GASTRITIS

2019 ◽  
pp. 28-32
Author(s):  
Van Huy Tran
Keyword(s):  
Helicobacter Pylori ◽  
Adverse Effects ◽  
Chronic Gastritis ◽  
Eradication Rate ◽  
High Rate ◽  
First Line ◽  
Helicobacter Pylori Eradication ◽  
Quadruple Therapy ◽  
First Line Therapy ◽  
Line Therapy

Background and aims: Efficacy with substitution of tetracycline with amoxicillin, an antibiotics having a very low resistance rate and a high tolerability, in bismuth quadruple therapy (BQT) have not been studied in Vietnam. Our study aimed to evaluate the efficacy and tolerability of modified BQT vs. standard BQT for first-line Helicobacter pylori eradication. Patients and methods: This is a randomized, prospective study. 120 patients with H.pylori positive-chronic gastritis were randomly divided into two groups. The RBMA group containing rabeprazole 20 mg, bismuth subsalicylic 524mg, metronidazole 500mg, amoxicillin 1000mg, all 2 times a day, for 14 days. The RBMT group received rabeprazole, bismuth subsalicylic, metronidazole and tetracycline. Evaluation for compliance and drug-related side effects were evaluated at the end of two weeks. 4-6 weeks after the end of treatment, the H.pylori eradication rate was determined by the C13urease breath test. Results: Eradication rate was not statistically significative different between the RBMA and the RBMT: 91.2%; 95% confidence interval, 78.2% - 96.7%) vs. 90%; 95% CI, 81.6% - 96.3%) by per-protocol analysis (p = 0.42) and 86.7% (95%CI, 75.84% - 93.09%) vs. 75% (95%CI, 62.1% - 85.3%) by intention-to-treat analysis (ITT, p = 0.06). Adverse effects were significant higher in the RBMT group than in the RBMA group (48.3% vs. 26.7%; p = 0.071) and rate of good compliance was significantly higher in RBMA group than in RBMT group (p < 0.05). Conclusion: The modified BQT including rabeprazole, bismuth, metronidazole and amoxicillin achieved a fairly high rate of H.pylori infection eradication with a higher compliance and lower rate of adverse effects compared to the BQT in patients with chronic gastritis. Further studies need to conduct to confirm this new regimens as a first-line therapy in our country. Key words: Modified bismuth quadruple therapy, BQT, Helicobacter pylori eradication

Sign in / Sign up

Export Citation Format

Share Document