The objective of this study was to assess the efficacy, safety and tolerability of vonoprazan, a novel potassium-competitive acid blocker, as a component of Helicobacter pylori eradication therapy.
A ...randomised, double-blind, multicentre, parallel-group study was conducted to verify the non-inferiority of vonoprazan 20 mg to lansoprazole 30 mg as part of first-line triple therapy (with amoxicillin 750 mg and clarithromycin 200 or 400 mg) in H pylori-positive patients with gastric or duodenal ulcer history. The first 50 patients failing first-line therapy with good compliance also received second-line vonoprazan-based triple therapy (with amoxicillin 750 mg and metronidazole 250 mg) as an open-label treatment.
Of the 650 subjects randomly allocated to either first-line triple therapy, 641 subjects completed first-line therapy and 50 subjects completed second-line therapy. The first-line eradication rate (primary end point) was 92.6% (95% CI 89.2% to 95.2%) with vonoprazan versus 75.9% (95% CI 70.9% to 80.5%) with lansoprazole, with the difference being 16.7% (95% CI 11.2% to 22.1%) in favour of vonoprazan, thus confirming the non-inferiority of vonoprazan (p<0.0001). The second-line eradication rate (secondary end point) was also high (98.0%; 95% CI 89.4% to 99.9%) in those who received second-line therapy (n=50). Both first-line triple therapies were well tolerated with no notable differences. Second-line triple therapy was also well tolerated.
Vonoprazan is effective as part of first-line triple therapy and as part of second-line triple therapy in H pylori-positive patients with a history of gastric or duodenal ulcer.
NCT01505127.
Epidemiology of Helicobacter pylori infection Burucoa, Christophe; Axon, Anthony
Helicobacter (Cambridge, Mass.),
September 2017, 2017-Sep, 2017-09-00, 20170901, Letnik:
22, Številka:
S1
Journal Article
Recenzirano
The study of Helicobacter pylori genetic variability brought us interesting data on the history of mankind. Based on multilocus sequence typing and more recently on whole‐genome sequencing, ...paleomicrobiology still attracts the attention of global researchers in relation to its ancestor roots and coexistence with humans. Three studies determining the prevalence of virulence factors illustrates the controversial results obtained since 30 years by studies trying to associate prevalence of different virulence markers and clinical outcomes of H. pylori infection. Three articles analyzed the prevalence and risk of multiple (genetically distinct isolates) and mixed (susceptible and resistant isolates) infections. A number of studies confirm that H. pylori prevalence is falling worldwide especially in the developed world and in children but that the level of infection is higher in certain ethnic minorities and in Migrants. There is little new in identifying the mode of H. pylori transmission though intrafamilial spread appears to be important. There have, however, been some interesting papers on the presence of the organism in food, water, and the oral cavity.
This review aimed to investigate the role of
Helicobacter pylori
flagella on the pathogenicity of this bacterium in humans.
Helicobacter pylori
is a flagellated pathogen that colonizes the human ...gastroduodenal mucosa and produces inflammation, and is responsible for gastrointestinal disease. Its pathogenesis is attributed to colonization and virulence factors. The primary function of
H. pylori
flagella is to provide motility. We believe that
H. pylori
flagella play an important role in the colonization of the gastrointestinal mucosa. Therefore, we reviewed previous studies on flagellar morphology and motility in order to explore the relationship between
H. pylori
flagella and pathogenicity. Further investigation is required to confirm the association between flagella and pathogenicity in
H. pylori.
Several conditions associated with reduced gastric acid secretion confer an altered risk of developing a gastric malignancy. Helicobacter pylori-induced atrophic gastritis predisposes to gastric ...adenocarcinoma, autoimmune atrophic gastritis is a precursor of type I gastric neuroendocrine tumours, whereas proton pump inhibitor (PPI) use does not affect stomach cancer risk. We hypothesised that each of these conditions was associated with specific alterations in the gastric microbiota and that this influenced subsequent tumour risk. 95 patients (in groups representing normal stomach, PPI treated, H. pylori gastritis, H. pylori-induced atrophic gastritis and autoimmune atrophic gastritis) were selected from a cohort of 1400. RNA extracted from gastric corpus biopsies was analysed using 16S rRNA sequencing (MiSeq). Samples from normal stomachs and patients treated with PPIs demonstrated similarly high microbial diversity. Patients with autoimmune atrophic gastritis also exhibited relatively high microbial diversity, but with samples dominated by Streptococcus. H. pylori colonisation was associated with decreased microbial diversity and reduced complexity of co-occurrence networks. H. pylori-induced atrophic gastritis resulted in lower bacterial abundances and diversity, whereas autoimmune atrophic gastritis resulted in greater bacterial abundance and equally high diversity compared to normal stomachs. Pathway analysis suggested that glucose-6-phospahte1-dehydrogenase and D-lactate dehydrogenase were over represented in H. pylori-induced atrophic gastritis versus autoimmune atrophic gastritis, and that both these groups showed increases in fumarate reductase. Autoimmune and H. pylori-induced atrophic gastritis were associated with different gastric microbial profiles. PPI treated patients showed relatively few alterations in the gastric microbiota compared to healthy subjects.
Helicobacter pylori infection is a major etiological factor in gastric diseases. However, clinical antibiotic therapy for H. pylori is limited by continuously decreased therapeutic efficacy and side ...effects to symbiotic bacteria. Herein, we develop an in vivo activatable pH-responsive graphitic nanozyme, PtCo@Graphene (PtCo@G), for selective treatment of H. pylori. Such nanozymes can resist gastric acid corrosion, exhibit oxidase-like activity to stably generate reactive oxygen species only in acidic gastric milieu and demonstrate superior selective bactericidal property. C
-PEG
-Benzeneboronic acid molecules are modified on PtCo@G, improving its targeting capability. Under acidic gastric pH, graphitic nanozymes show notable bactericidal activity toward H. pylori, while no bacterial killing is observed under intestinal conditions. In mouse model, high antibacterial capability toward H. pylori and negligible side effects toward normal tissues and symbiotic bacteria are achieved. Graphitic nanozyme displays the desired enzyme-like activities at corresponding physiological sites and may address critical issues in clinical treatment of H. pylori infections.
Since the discovery of Helicobacter pylori(H. pylori) in 1983, numerous detection methods for the presence of the bacterium have been developed. Each one of them has been associated with advantages ...and disadvantages. Noninvasive tests such as serology, 13 C urea breath test(UBT) and stool antigen tests are usually preferred by the clinicians. Serology has its own limitation especially in endemic areas while 13 C UBT is technically very demanding. The stool antigen detection method, although specific, is usually associated with poor sensitivity. The 13 C UBT is believed to be specific, but with present revelation of the fact that stomach is colonized by many other urease producing bacteria makes it questionable. Histology, culture, rapid urease test and polymerase chain reaction(PCR) are the tests which are carried out on antral biopsies collected by invasive means. Histology has been proposed to be very sensitive and specific but the question is how by simply looking the morphology of the bacteria in the microscope, one can claim that the curved bacterium is exclusively H. pylori. Rapid urease test(RUT), the doctor’s test, is also challenged because the presence of other urease producing bacteria in the stomach cannot be denied. Moreover, RUT has been reported with poor sensitivity specially, when density of the bacterium is low. Isolation of H. pylori is essential to investigate its growth requirements, antibiotic susceptibility testing, studying virulence factor to develop vaccine and many more explorations. It has also got several disadvantages i.e., special condition for transporting, media, incubation and few days waiting for the colonies to appear, apart from the speed essentially needed to process the specimens. Till date, majority of the microbiological laboratories in the world are not equipped and trained to isolate such fastidious bacterium. The option left is PCR methods to detect H. pylori ’s DNA in gastric mucosa, gastric juice, saliva, dental plaques and environmental specimens. There are speculations for false positivity due to detection of non-pylori Helicobacters due to genetic sharing; and false negativity due to low bacterial counts and presence of PCR inhibitors. However, specimen collection, transportation and processing do not require speed and special conditions. PCR based diagnosis may be considered as gold standard by designing primers extremely specific to H. pylori and targeting at least more than one conserved genes. Similarly specificity of PCR may be improved by use of internal Primers. Further, nested PCR will take care of false negatives by countering the effect of PCR inhibitors and low bacterial counts. Therefore, nested PCR based methods if performed properly, may be proposed as gold standard test.
Epidemiology of Helicobacter pylori Infection Eusebi, Leonardo H.; Zagari, Rocco M.; Bazzoli, Franco
Helicobacter (Cambridge, Mass.),
September 2014, Letnik:
19, Številka:
s1
Journal Article
Recenzirano
Odprti dostop
Medline and PubMed databases were searched on epidemiology of Helicobacter pylori for the period of April 2013–March 2014. Several studies have shown that the prevalence of H. pylori is still high in ...most countries. In north European and North American populations, about one‐third of adults are still infected, whereas in south and east Europe, South America, and Asia, the prevalence of H. pylori is often higher than 50%. H. pylori remains highly prevalent in immigrants coming from countries with high prevalence of H. pylori. However, the lower prevalence of infection in the younger generations suggests a further decline of H. pylori prevalence in the coming decades. Low socioeconomic conditions in childhood are confirmed to be the most important risk factors for H. pylori infection. Although the way the infection is transmitted is still unclear, interpersonal transmission appears to be the main route. Finally, H. pylori recurrence after successful eradication can still occur, but seems to be an infrequent event.
Abstract Helicobacter pylori ( H. pylori ) infect over half of the world’s population. The prevalence of H. pylori infection and the predominant genotype of H. pylori virulence factors vary ...considerably across different geographical regions. H. pylori could uniquely persist for decades in the harsh stomach environment, where it damages the gastric mucosa and changes the pattern of gastric hormone release, thereby affects gastric physiology. By utilizing various virulence factors, H. pylori targets different cellular proteins to modulate the host inflammatory response and initiate multiple “hits” on the gastric mucosa, resulting in chronic gastritis and peptic ulceration. Among the long-term consequences of H. pylori infection is gastric malignancies, particularly gastric cancer (GC) and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. As such, H. pylori has been recognized as a class I carcinogen by the International Agency for Research on Cancer. Despite a close causal link between H. pylori infection and the development of gastric malignancies, the precise mechanisms involved in this process are still obscure. Studies over the past two decades have revealed that H. pylori exert oncogenic effects on gastric mucosa through a complex interaction between bacterial factors, host factors, and environmental factors. Numerous signaling pathways can be activated by H. pylori. In this review, we aim to elaborate on the recent developments in the pathophysiological mechanisms of H. pylori -induced gastric inflammation and gastric cancer.
(
) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. However, its prevalence varies among different geographic areas, and is influenced by several factors. ...The infection can be acquired by means of oral-oral or fecal-oral transmission, and the pathogen possesses various mechanisms that improve its capacity of mobility, adherence and manipulation of the gastric microenvironment, making possible the colonization of an organ with a highly acidic lumen. In addition,
presents a large variety of virulence factors that improve its pathogenicity, of which we highlight cytotoxin associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and gamma-glutamyl transpeptidase. The host immune system, mainly by means of a Th1-polarized response, also plays a crucial role in the infection course. Although most
-positive individuals remain asymptomatic, the infection predisposes the development of various clinical conditions as peptic ulcers, gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. Invasive and non-invasive diagnostic methods, each of them with their related advantages and limitations, have been applied in
detection. Moreover, bacterial resistance to antimicrobial therapy is a major challenge in the treatment of this infection, and new therapy alternatives are being tested to improve
eradication. Last but not least, the development of effective vaccines against
infection have been the aim of several research studies.
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