scholarly journals Helicobacter pylori.

1997 ◽  
Vol 10 (4) ◽  
pp. 720-741 ◽  
Author(s):  
B E Dunn ◽  
H Cohen ◽  
M J Blaser
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Lymphoma ◽  
Developed Countries ◽  
Pcr Analysis ◽  
Gastric Tissue ◽  
Negative Bacterium ◽  
Breath Tests ◽  
Ulcer Disease ◽  
Gastric Lumen ◽  
H Pylori

Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.

scholarly journals Helicobacter pylori Persistence: an Overview of Interactions between H. pylori and Host Immune Defenses

2006 ◽  
Vol 19 (4) ◽  
pp. 597-613 ◽  
Author(s):  
Holly M. Scott Algood ◽  
Timothy L. Cover
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Gastric Lymphoma ◽  
Host Defenses ◽  
Negative Bacterium ◽  
Ulcer Disease ◽  
Immune Clearance ◽  
Immune Defenses ◽  
H Pylori

SUMMARY Helicobacter pylori is a gram-negative bacterium that persistently colonizes more than half of the global human population. In order to successfully colonize the human stomach, H. pylori must initially overcome multiple innate host defenses. Remarkably, H. pylori can persistently colonize the stomach for decades or an entire lifetime despite development of an acquired immune response. This review focuses on the immune response to H. pylori and the mechanisms by which H. pylori resists immune clearance. Three main sections of the review are devoted to (i) analysis of the immune response to H. pylori in humans, (ii) analysis of interactions of H. pylori with host immune defenses in animal models, and (iii) interactions of H. pylori with immune cells in vitro. The topics addressed in this review are important for understanding how H. pylori resists immune clearance and also are relevant for understanding the pathogenesis of diseases caused by H. pylori (peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma).

Immune responses to Helicobacter pylori colonization: mechanisms and clinical outcomes

2006 ◽  
Vol 110 (3) ◽  
pp. 305-314 ◽  
Author(s):  
Cynthia Portal-Celhay ◽  
Guillermo I. Perez-Perez
Keyword(s):  
Immune Response ◽  
Helicobacter Pylori ◽  
Immune Responses ◽  
Gastric Lymphoma ◽  
Gastric Epithelium ◽  
Immune Effector ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
Increased Risk ◽  
H Pylori

Helicobacter pylori colonizes the stomachs of half of the world's population and usually persists in the gastric mucosa of human hosts for decades or life. Although most H. pylori-positive people are asymptomatic, the presence of H. pylori is associated with increased risk for the development of peptic ulcer disease, gastric adenocarcinoma and gastric lymphoma. The development of a sustained gastric inflammatory and immune response to infection appears to be pivotal for the development of disease. During its long co-existence with humans, H. pylori has evolved complex strategies to maintain a mild inflammation of the gastric epithelium while limiting the extent of immune effector activity. In this review, the nature of the host immune response to H. pylori infection and the mechanism employed by the bacterium to evade them is considered. Understanding the mechanisms of colonization, persistence and virulence factors of the bacterium as well as the innate and adaptive immune responses of the host are critically important for the development of new strategies to prevent the development of H. pylori-induced gastroduodenal disease.

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.

The rod-to-coccoid body transformation in cultures of Helicobacter pylori

1990 ◽  
Vol 48 (3) ◽  
pp. 626-627
Author(s):  
A. R. Crooker ◽  
W. G. Kraft ◽  
T. L. Beard ◽  
M. C. Myers
Keyword(s):  
Helicobacter Pylori ◽  
Growth Cycle ◽  
Negative Bacterium ◽  
Body Formation ◽  
Coccoid Form ◽  
Spiral Form ◽  
Prolonged Culture ◽  
H Pylori ◽  
Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

scholarly journals MALT lymphoma: epidemiology, clinical diagnosis and treatment

2018 ◽  
Vol 11 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Petruta Violeta Filip ◽  
◽  
Denisa Cuciureanu ◽  
Laura Sorina Diaconu ◽  
Ana Maria Vladareanu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
B Cell ◽  
Malt Lymphoma ◽  
Cell Lymphoma ◽  
Gastric Lymphoma ◽  
Eradication Therapy ◽  
B Cell Lymphoma ◽  
Gastric Malt Lymphoma ◽  
H Pylori

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

scholarly journals Evaluation of Helicobacter pylory colonization by serologic test (IgG) and dyspepsia in volunteers from the countryside of Monte Negro, in the Brazilian western Amazon region

2010 ◽  
Vol 52 (4) ◽  
pp. 203-206 ◽  
Author(s):  
Rafael Bernardon Ribeiro ◽  
Herlon Saraiva Martins ◽  
Vera Aparecida dos Santos ◽  
Marcelo el Khouri ◽  
Leandro Savoy Duarte ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Rural Areas ◽  
Age Groups ◽  
Developed Countries ◽  
Progressive Increase ◽  
Amazon Region ◽  
Statistical Association ◽  
Serologic Test ◽  
Positive Serology ◽  
H Pylori

The present study intended to analyze the seroprevalence of Helicobacter pylori, IgG, and its relation to dyspepsia in a population from the western Amazon region. During the "Projeto Bandeira Científica", a University of São Paulo Medical School program, in Monte Negro's rural areas, state of Rondônia, 266 blood samples were collected from volunteers. The material was tested for IgG antibodies anti-Helicobacter pylori by ELISA method and the participants were also interviewed on dyspepsia, hygiene and social aspects. Participants aged between five and 81 years old (34 years on average), 149 (56%) were female and 117 (44%) male. We found 210 (78.9%) positive, 50 (18.8%) negative and six (2.3%) undetermined samples. Dyspeptic complaints were found in 226 cases (85.2%). There was no statistical association between dyspepsia and positive serology for H. pylori. We concluded that the seroprevalence in all age categories is similar to results found in other studies conducted in developing countries, including those from Brazil. On the other hand, the seroprevalence found in Monte Negro was higher than that reported in developed countries. As expected, there was a progressive increase in the positivity for H. pylori in older age groups.

scholarly journals Identification of Markers for Helicobacter pylori Strains Isolated from Children with Peptic Ulcer Disease by Suppressive Subtractive Hybridization

2006 ◽  
Vol 74 (7) ◽  
pp. 4064-4074 ◽  
Author(s):  
Mónica Oleastro ◽  
Lurdes Monteiro ◽  
Philippe Lehours ◽  
Francis Mégraud ◽  
Armelle Ménard
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Subtractive Hybridization ◽  
Suppressive Subtractive Hybridization ◽  
Ulcer Disease ◽  
Lipopolysaccharide Biosynthesis ◽  
The Difference ◽  
H Pylori

ABSTRACT Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent. We used suppressive subtractive hybridization for comparative genomics between H. pylori strains isolated from a 5-year-old child with duodenal ulcer and from a sex- and age-matched child with gastritis only. The prevalence of the 30 tester-specific subtracted sequences was determined on a collection of H. pylori strains from children (15 ulcers and 30 gastritis) and from adults (46 ulcers and 44 gastritis). Two of these sequences, jhp0562 (80.0% versus 33.3%, P = 0.008) and jhp0870 (80.0% versus 36.7%, P = 0.015), were highly associated with PUD in children and a third sequence, jhp0828, was less associated (40.0% versus 10.0%, P = 0.048). Among adult strains, none of the 30 sequences was associated with PUD. However, both jhp0562 and jhp0870 were less prevalent in adenocarcinoma strains than in PUD strains from children and adults, the difference being statistically significant for jhp0870. In conclusion, two H. pylori genes were identified as being strongly associated with PUD in children, and their putative roles as an outer membrane protein for jhp0870 and in lipopolysaccharide biosynthesis for jhp0562, suggest that they may be novel virulence factors of H. pylori.

scholarly journals Helicobacter pylori colonization and oral health in children

2017 ◽  
Vol 12 (2) ◽  
pp. 41-44
Author(s):  
Vasile Valeriu LUPU ◽  
◽  
Gabriela PĂDURARU ◽  
Anca ADAM ◽  
Ana-Maria DĂBULEANU ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Oral Health ◽  
Gastric Mucosa ◽  
Oral Cavity ◽  
Gold Standard ◽  
Dental Plaque ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Standard Triple Therapy ◽  
H Pylori

Helicobacter pylori (H. pylori) is a microaerophilic gram-negative bacterium infecting approximately one half of the world’s population. The oral cavity and dental plaque may be a reservoir for H. pylori infection. Diagnosis of H. pylori infection in children differs from that of adults. Although H. pylori has long been known to be detected in the oral cavity, the significance of such findings are controversial. Oral H. pylori may play an important role in re-infection of the gastric mucosa. The gold standard for eradicating H. pylori infection is standard triple therapy. The studies have shown promising results in the management of both oral and gastric H. pylori.

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 Prevalence of Helicobacter pylori infection among patients undergoing upper gastrointestinal endoscopy

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Vudumula Vijaya Lakshmi
Keyword(s):  
Duodenal Ulcer ◽  
Helicobacter Pylori ◽  
Normal Population ◽  
Gastric Ulcers ◽  
Upper Gastrointestinal Endoscopy ◽  
Contributing Factors ◽  
Duodenal Ulcers ◽  
Female Ratio ◽  
Ulcer Disease ◽  
H Pylori

Helicobacter pylori (H. pylori) has a role in the multifactorial etiology of peptic ulcer disease. A link between H. pylori infection and duodenal ulcer disease is now established. Other contributing factors and their interaction with the organism may initiate the ulcerative process. The fact that eradication of H. pylori infection leads to a long-term cure in the majority of duodenal ulcer patients and the fact that the prevalence of infection is higher in ulcer patients than in the normal population are cogent arguments in favor of it being the primary cause of the ulceration. This study was under taken at the Department of surgery, Narayana medical college, Nellore from January 2007 to July 2008. A total of 150 patients with duodenal ulcers, gastric ulcers, antral gastritis, gastric carcinoma and dyspepsia of any kind were studied. Maximum number of cases were in the age group of 31 years to 50 years among both sexes and number of cases gradually decreased after 50 years of age in males and females. Males were more in number and male to female ratio is (2.75:1) approximately 3:1.

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