scholarly journals Protection against Experimental Helicobacter pylori Infection after Immunization with Inactivated H. pylori Whole-Cell Vaccines

2002 ◽  
Vol 70 (11) ◽  
pp. 6383-6388 ◽  
Author(s):  
S. Raghavan ◽  
M. Hjulström ◽  
J. Holmgren ◽  
A.-M. Svennerholm

ABSTRACT The protective effect of therapeutic oral immunization with homologous and heterologous formalin-inactivated Helicobacter pylori cells given together with cholera toxin as an adjuvant was evaluated with C57BL/6 mice infected with H. pylori Sydney strain 1 (SS1). The bacteria used for immunization were strains that were either homologous or heterologous with regard to the O antigen (i.e., the Lewis antigen [Le antigen]) expressed by the lipopolysaccharide of the infecting H. pylori SS1 strain. We found that repeated oral immunization with inactivated H. pylori SS1 cells can significantly inhibit an existing infection (P < 0.001) and that the protection induced by such therapeutic immunization extends to protection against reinfection (P < 0.001). A similar level of protection was also achieved by immunization with another inactivated H. pylori strain having the same O antigen (Le antigen) as the infecting H. pylori SS1 strain. In contrast, immunization with inactivated strains expressing a heterologous O antigen, Lex, provided less protection or no protection. Immunization with H. pylori lysate preparations, on the other hand, resulted in significant comparable protection whether the lysates were prepared from an Lex strain or an Ley strain. Postimmunization gastritis was seen in mice that were protected after vaccination but not in unimmunized or unprotected mice. In conclusion, therapeutic immunization with inactivated H. pylori whole-cell vaccines may provide strong protection both against experimental H. pylori infection and against later reinfection.

2002 ◽  
Vol 70 (8) ◽  
pp. 4621-4627 ◽  
Author(s):  
S. Raghavan ◽  
A.-M. Svennerholm ◽  
J. Holmgren

ABSTRACT Therapeutic vaccination is an attractive strategy to control infection and disease caused by Helicobacter pylori. In mice infected with H. pylori we have studied the protective effect of oral immunization with an H. pylori lysate preparation given together with the mucosal adjuvant cholera toxin (CT), both against the initial infection and against a later reinfection challenge. We have also examined the effects of treatment with the CT adjuvant alone on H. pylori infection and reinfection. Specific immunization with lysate was found to result in a sixfold reduction of the extent (bacterial load) of the primary infection and also to provide similar levels of protection against reinfection. However, these effects were associated with severe postimmunization gastritis. In contrast, oral treatment with CT alone at the time of initial infection, while unable to suppress the initial infection, gave rise to a 20-fold reduction in bacterial load upon reinfection without causing any associated gastric inflammation. Both the infected animals that were specifically immunized and those that were treated with CT only displayed increased in vitro proliferative responses of mononuclear cells to H. pylori antigens. Antibody levels in response to H. pylori were on the other hand only marginally increased after treatment with CT, whereas they were markedly elevated after immunization with lysate plus CT, with a rise in both (Th2-driven) immunoglobulin G1 (IgG1) and, especially, (Th1-driven) IgG2a antibodies. The results illustrate the complex balance between protection and harmful inflammation after postinfection vaccination against H. pylori as studied in a mouse model.


2001 ◽  
Vol 100 (3) ◽  
pp. 291-298 ◽  
Author(s):  
Byung Oh KIM ◽  
Sung Seup SHIN ◽  
Young Hyo YOO ◽  
Suhkneung PYO

Helicobacter pylori is a major cause of gastric-associated diseases. To evaluate the efficacy of a possible vaccine antigen against H. pylori infection, the chimaeric construct adhesin–CTXA2B, derived from H. pylori adhesin genetically coupled to cholera toxin (CTX) subunits A2 and B (CTXA2B), was expressed in Escherichia coli as an insoluble recombinant chimaeric protein. The protein was then purified by denaturation, renaturation and size-exclusion chromatography. The composition of purified adhesin–CTXA2B was verified by SDS/PAGE and Western blotting with antibodies to antigenic components of adhesin and CTXB, and confirmed as a chimaeric protein with GM1-ganglioside binding activity and adhesin epitopes by a GM1-ELISA developed using antibodies to adhesin. Oral immunization of mice with adhesin–CTXA2B induced higher levels of mucosal IgA and serum IgG antibodies to H. pylori adhesin and to CTXB than in mice immunized with adhesin or CTXA2B alone. Adhesin–CTXA2B was also demonstrated to be a potential protective antigen in a mouse model of H. pylori infection. The immunization of mice with adhesin–CTXA2B protected 62.5% of mice infected with H. pylori SS1 strain, whereas adhesin immunization was not able to confer protection to mice. This protection may be correlated with high levels of mucosal IgA and serum IgG antibodies against H. pylori adhesin. Taken together, the results indicate that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin–CTXA2B chimaeric protein could be a potential component in future H. pylori vaccine development.


2019 ◽  
Vol 37 (6) ◽  
pp. 434-443
Author(s):  
Bernadett Márkus ◽  
László Herszényi ◽  
Melinda Matyasovszky ◽  
Krisztián Vörös ◽  
Péter Torzsa ◽  
...  

Background Aims: Most patients with Helicobacter pylori infection are consulted for the first time by family physicians. We aimed to survey the adherence to the newest guidelines of the management of H. pylori infection in the primary and secondary care settings in Hungary. Methods: From a total of 793 physicians, 94 trainees in family medicine, 334 family physicians without and 195 with board certification in internal medicine, 87 internists, 78 family paediatricians were invited to take part in the study. Diagnostic and therapeutic attitudes towards H. pylori infection were compared by a voluntary and anonymous questionnaire. Results: Participants test for H. pylori infection in 92.8% of cases with a family history of peptic ulcer or 76.9% of gastric cancer, 68.9% of dyspepsia and 49.9% of non-specific abdominal complaints, before initiation of non-steroidal anti-inflammatory drug (NSAID; 17.3%) and antiplatelet treatment (14.5%), respectively. They confirm the success of eradication therapy in 88.1% mainly by urea breath test. Most of them initiate eradication therapy by themselves and only 22.4% refer their patients to a gastroenterologist. Clarithromycin-based standard triple therapy is the most preferred (62.1%) and only 3.7% choose quadruple combination with bismuth as first-line and 48.1% as second-line therapy. We found significant differences between groups with respect to the physicians’ own infection, localization of practice, and sources of information on H. pylori infection. Internists are more likely to clarify H. pylori status before the initiation of NSAID and antiplatelet therapies, initiate second-line therapies and use bismuth compared to the other groups. Family physicians with board certification in internal medicine are also prone to start eradication therapy and less prone to refer patients to a gastroenterologist. Family paediatricians prefer stool antigen determination, screen family members and prefer gastroenterologist consultation more often, and use bismuth less frequently than the other groups. Family physicians with previous infection check for H. pyloriinfection more frequently before the initiation of NSAID treatment and are more likely to use histology to detect H. pylori. Postgraduate trainings were the most popular source of information. Conclusion: The adherence to the recent recommendations of current guidelines is moderate. There is a need to increase adherence to current recommendations by family physicians and internists.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 845
Author(s):  
Candace Goodman ◽  
Katrina N. Lyon ◽  
Aitana Scotto ◽  
Cyra Smith ◽  
Thomas A. Sebrell ◽  
...  

Helicobacter pylori infection is commonly treated with a combination of antibiotics and proton pump inhibitors. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed the antibacterial effects of black and red raspberries and blackberries on H. pylori. Freeze-dried powders and organic extracts from black and red raspberries and blackberries were prepared, and high-performance liquid chromatography was used to measure the concentrations of anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, a high-throughput metabolic growth assay based on the Biolog system was developed and validated with the antibiotic metronidazole. Biocompatibility was analyzed using human gastric organoids. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. Antimicrobial activity was higher for extracts than powders and appeared to be independent of the anthocyanin concentration. Importantly, human gastric epithelial cell viability was not negatively impacted by black raspberry extract applied at the concentration required for complete bacterial growth inhibition. Our data suggest that black and red raspberry and blackberry extracts may have potential applications in the treatment and prevention of H. pylori infection but differ widely in their MICs. Moreover, we demonstrate that the Biolog metabolic assay is suitable for high-throughput antimicrobial susceptibility screening of H. pylori.


2018 ◽  
Vol 7 (5) ◽  
pp. 217-224
Author(s):  
Zouaouia Chama ◽  
Khedoudj Kanoun ◽  
Fatima Zohra Elkadi ◽  
Kara Turqui Douidi ◽  
Noria Harir ◽  
...  

Helicobacter pylori infection concerns half of the world’s population, mainly in developing countries. It causes several gastrodudenal pathologies such as gastritis, ulcer and gastric adenocarcinoma. The aim of our study was to determine the prevalence of H.pylori infection and to assess the impact of different epidemiological factors as well as principal gastric diseases associ-ated to this infection. We underwent a prospective study during 18 months (month 2016-month 2017) which implicated 201 symptomatic patients for gastric fiboptic endoscopy at the level of Sidi Bel Abbes University hospital. We collected patients’ biopsies to perform a histological study and H. pylori culture. H. pylori identification was carried out based on bacteriological and biochemical analysis. The middle age of our population was (47.29 ±15.97ans) and the sex-ratio =0,8. The global prevalence of Helicobacter pylori infection is of 61.2% (123/201). This rate, after a statistic analysis, seems to be significantly related to age. It is particularly high especially for patients belonging to age range (20-30)-(51-60) years. The gender did not affect the infection prevalence that is more frequent in the gastritis case. We noticed also that HP infection prevalence was important in SBA the hospital. The range age (20-30)-(51-60) years had the highest prevalence of H. pylori and of gastritis which might be a risky ground of gastric cancer appearance. The ulcer pathology maximal rate concerned the group of 51 to 60 years. Above this age, this rate dropped whereas the number of patients suffering from gastric cancer, which presents an important rate in our study, increase for the group of 61-70 years.


2017 ◽  
Vol 9 (1) ◽  
pp. 87-93
Author(s):  
Sakolwan Suchartlikitwong ◽  
Kamolyut Lapumnuaypol ◽  
Rungsun Rerknimitr ◽  
Duangporn Werawatganon

Abstract Background The current epidemiology of upper gastrointestinal bleeding (UGIB) in Thailand is poorly understood and the reported prevalence of Helicobacter pylori infection is outdated. Objectives To investigate the etiologies of UGIB and prevalence of H. pylori infection in Thailand, including its association with UGIB. Methods We retrieved information regarding patients attending the endoscopic unit of King Chulalongkorn Memorial Hospital from June 2007 to January 2013. A database search using keywords “upper gastrointestinal bleeding” and “iron deficiency” was used. From 4,454 diagnoses, after exclusion criteria, 3,488 patients (2,042 male (58.5%) and 1,446 female (41.5%); mean age 63.3 ± 15.94 years, range 13–103 years) were included. Results The three most common causes of UGIB were peptic ulcer (38.2%), nonulcer-mucosal lesions (23.4%), and esophageal-related causes (20.4%). The 5 year-incidence of H. pylori was 25%–30%. The overall prevalence was 27%. The prevalence of H. pylori infection was found to decrease with age from 43.8% at <40 years to 21.7% at >79 years old. H. pylori infection was significantly associated with duodenal and gastroduodenal ulcers. Cirrhosis and nonulcer-mucosal lesions were significantly unrelated to H. pylori infection. Patients with concurrent cirrhosis with peptic ulcer were found to be negative for H. pylori infection. Conclusion Peptic ulcer is the leading cause of UGIB in Thailand. However, its incidence is declining. Patients who presented to hospital with UGIB were older, compared with those a decade ago. H. pylori infection plays an important role in UGIB and its incidence was stable during the past 5 years.


2005 ◽  
Vol 19 (7) ◽  
pp. 399-408 ◽  
Author(s):  
Nicola L Jones ◽  
Philip Sherman ◽  
Carlo A Fallone ◽  
Nigel Flook ◽  
Fiona Smaill ◽  
...  

As an update to previously published recommendations for the management of Helicobacter pylori infection, an evidence-based appraisal of 14 topics was undertaken in a consensus conference sponsored by the Canadian Helicobacter Study Group. The goal was to update guidelines based on the best available evidence using an established and uniform methodology to address and formulate recommendations for each topic. The degree of consensus for each recommendation is also presented. The clinical issues addressed and recommendations made were: population-based screening for H pylori in asymptomatic children to prevent gastric cancer is not warranted; testing for H pylori in children should be considered if there is a family history of gastric cancer; the goal of diagnostic interventions should be to determine the cause of presenting gastrointestinal symptoms and not the presence of H pylori infection; recurrent abdominal pain of childhood is not an indication to test for H pylori infection; H pylori testing is not required in patients with newly diagnosed gastroesophageal reflux disease; H pylori testing may be considered before the use of long-term proton pump inhibitor therapy; testing for H pylori infection should be considered in children with refractory iron deficiency anemia when no other cause has been found; when investigation of pediatric patients with persistent or severe upper abdominal symptoms is indicated, upper endoscopy with biopsy is the investigation of choice; the 13C-urea breath test is currently the best noninvasive diagnostic test for H pylori infection in children; there is currently insufficient evidence to recommend stool antigen tests as acceptable diagnostic tools for H pylori infection; serological antibody tests are not recommended as diagnostic tools for H pylori infection in children; first-line therapy for H pylori infection in children is a twice-daily, triple-drug regimen comprised of a proton pump inhibitor plus two antibiotics (clarithromycin plus amoxicillin or metronidazole); the optimal treatment period for H pylori infection in children is 14 days; and H pylori culture and antibiotic sensitivity testing should be made available to monitor population antibiotic resistance and manage treatment failures.


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