The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

medizin.uni-magdeburg.de

Current concepts in the management o

Noninvasive antigen-based assay for assessing Helicobacter pylori eradication: A European multicenter study

OBJECTIVE: In a recently published multicenter study involving 501 patients undergoing esophagogastroduodenoscopy (EGD) throughout Europe, we showed the high accuracy of a recently developed simple test (HpSA) to detect Helicobacter pylori (H. pylori) antigens in stools of untreated patients. The aim of this study was to assess the diagnostic usefulness of HpSA compared with 13C UBT shortly after H. pylori eradication treatment. METHODS: Of the 501 patients enrolled in the validation study, 279 were found to be H. pylori-positive. These patients were given H. pylori eradicating regimen and asked to return for follow-up EGD with biopsies, 13C UBT and HpSA testing 4 wk after therapy. Follow-up results were available for 235 patients. Of these, 162 consented to all testing and 73 consented only to 13C UBT and HpSA testing. We assessed sensitivity and specificity of both HpSA and 13C UBT compared with biopsy-based methods in the 162 patients, who accepted follow-up EGD. We also assessed sensitivity and specificity of HpSA compared with 13C UBT, arbitrarily chosen as the gold standard, in the whole population of 235 patients. RESULTS: Sensitivity and specificity in 162 patients who consented to a second EGD were 93.8% (CI: 85.4-100%) and 96.9% (CI: 93.9-99.9%) for HpSA, and 90.6% (CI: 80.5-100%) and 99.2% (CI: 97.7- 100%) for UBT. Using EGD-based methods as the gold standard, 130 of the 162 treated patients' H. pylori infection were eradicated (125 HpSA-negative, one borderline, and four false-positive; 129 13C UBT-negative, one false- positive), and 32 remained H. pylori-infected (30 HpSA-positive, two false- negative, 29 13C UBT-positive, three false negative). The overall eradication rate was 80.2%. The sensitivity and specificity of HpSA relative to UBT as the gold standard in the overall population (n = 235) were 95.6% (CI: 89.6-100%) and 94.7% (CI: 91.5-97.9%), respectively. CONCLUSIONS: HpSA has proven to be a useful method in posttreatment eradication testing for H. pylori. Its ease of use, speed, and noninvasive nature make HpSA testing an ideal method for post-treatment monitoring where a second EGD may not be justified. (C) 2000 by Am. Coll. of Gastroenterology

Current concepts in the management of Helicobacter pylori infection-The Maastricht III Consensus Report

Background: Guidelines on the management of Helicobacter pylori, which cover indications for management and treatment strategies, were produced in 2000. Aims: To update the guidelines at the European Helicobacter Study Group (EHSG) Third Maastricht Consensus Conference, with emphasis on the potential of H pylori eradication for the prevention of gastric cancer. Results: Eradication of H pylori infection is recommended in (a) patients with gastroduodenal diseases such as peptic ulcer disease and low grade gastric, mucosa associated lymphoid tissue (MALT) lymphoma; (b) patients with atrophic gastritis; (c) first degree relatives of patients with gastric cancer; (d) patients with unexplained iron deficiency anaemia; and (e) patients with chronic idiopathic thrombocytopenic purpura. Recurrent abdominal pain in children is not an indication for a ‘‘test and treat’’ strategy if other causes are excluded. Eradication of H pylori infection (a) does not cause gastro-oesophageal reflux disease (GORD) or exacerbate GORD, and (b) may prevent peptic ulcer in patients who are naı¨ve users of non-steroidal antiinflammatory drugs (NSAIDs). H pylori eradication is less effective than proton pump inhibitor (PPI) treatment in preventing ulcer recurrence in long term NSAID users. In primary care a test and treat strategy using a noninvasive test is recommended in adult patients with persistent dyspepsia under the age of 45. The urea breath test, stool antigen tests, and serological kits with a high accuracy are non-invasive tests which should be used for the diagnosis of H pylori infection. Triple therapy using a PPI with clarithromycin and amoxicillin or metronidazole given twice daily remains the recommended first choice treatment. Bismuth-containing quadruple therapy, if available, is also a first choice treatment option. Rescue treatment should be based on antimicrobial susceptibility. Conclusion: The global burden of gastric cancer is considerable but varies geographically. Eradication of H pylori infection has the potential to reduce the risk of gastric cancer developmen

Diagnosis of Helicobacter pylori infection with a new non-invasive antigen-based assay

Background. Helicobacter pylori is a common human pathogen implicated in certain gastrointestinal diseases. In the search for new non-invasive techniques to diagnose H pylori infection, we evaluated an EIA for H pylori antigen in stool (HpSA). Methods. In a prospective multicentre study, stool specimens from 501 patients (276 men, 225 women; age range 17-88 years, mean 52) undergoing gastroscopy in 11 centres throughout Europe were tested with HpSA and the carbon-13-urea breath test. At endoscopy, four biopsy samples were taken for histology (haematoxylin and eosin) and H pylori detection (giemsa in both antrum and corpus, culture and rapid urease test). Patients were defined as positive for H pylori if histology (antrum, corpus, or both) and urease test were positive, or if culture was positive. Patients classified as having H pylori infection received an eradication regimen; 107 were reassessed 4 weeks after therapy. Findings. Of 272 patients with H pylori infection by the predefined criteria, 256 were positive by HpSA (sensitivity 94.1% [95% CI 90.6-96.6]). Of 219 patients without infection, 201 were negative by HpSA (specificity 91.8% [87.3-95.1]). Interpretation. The stool assay was a reliable and easy-to-use tool for diagnosis of H pylori infection. The test was accurate even shortly after treatment

World Gastroenterology Organisation Global Guidelines: Helicobacter pylori in developing countries August 2010

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Helicobacter pylori in developing countries. World gastroenterology organisation global guideline

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