Where to Biopsy to Detect Helicobacter pylori and How Many Biopsies Are Needed to Detect Antibiotic Resistance in a Human Stomach

Evaluation of guidelines for diagnosis and treatment of Helicobacter pylori infection

BACKGROUND

To systematically evaluate the quality of the guidelines for the diagnosis and treatment of Helicobacter pylori infection and to analyze the differences and reasons for the key recommendations in the guidelines.

METHODS

Databases and websites were systematically searched to obtain guidelines for the diagnosis and treatment of Helicobacter pylori infection. Four independent reviewers used the Guideline Evaluation Tool (AGREE II) to evaluate the included guidelines. The intraclass correlation coefficient (ICC) and Fleiss' kappa coefficient were used to measure the consistency of evaluation guidelines between guide reviewers. Differences between guidelines and the reasons for the differences were analyzed by comparing the recommendations of different guidelines and the evidence supporting the recommendations.

RESULTS

A total of 17 guidelines for Helicobacter pylori infection were included in this study. The AGREE II scores of these guidelines were low overall, with 4 of them had a score of over 60%, which indicates that the guidelines are recommended, and 13 of them having a score ranging from 30 to 60%, which indicates that the guidelines are recommended but need to be revised, while no guideline had a score of 30% or less, which indicates that they were not recommended. The analysis of these guidelines found that there were some differences in the main recommendations. Not all guidelines recommend sequential therapy as the recommended therapy. Whether bismuth quadruple therapy should be used as the recommended first-line therapy is unclear. The antibiotic resistance rate is different in different regions. Combined with the local antibiotic sensitivity test, the eradication rate of Helicobacter pylori can be improved.

CONCLUSION

There are significant differences in the quality of Helicobacter pylori infection guidelines and the key recommendations. Improving the deficiencies of existing guidelines is an effective way to develop high-quality guidelines and make reasonable recommendations for the treatment of Helicobacter pylori infection in the future.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

Background

Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics.

Method

A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance.

Results

The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I² = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05).

Conclusion

Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Prevalence of antibiotic heteroresistance associated with Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

Heteroresistance is a general term to describe diverse responses to specific antibiotics that can occur due to infection with either multiple bacterial strains or microevolution of a single strain during chronic infection. Due to limited information regarding heteroresistance Helicobacter pylori (H. pylori) infection, the current study was carried out to evaluate the prevalence of this phenomenon.

METHODS

For this study, all potential relevant studies were collected by searching international databases such as ISI Web of Science, PubMed, Scopus, ScienceDirect, ProQuest, Embase, DOAJ, China National Knowledge Infrastructure (CNKI), and Google Scholar. Finally, the frequency of heteroresistance H. pylori infection was measured using the event rate corresponding to 95% confidence intervals.

RESULTS

A total of 26 studies met our criteria; the eligible studies were related to the years 2001-2022. Our results showed that the prevalence of heteroresistance H. pylori strains was 60.1% to clarithromycin, 61.1% to metronidazole, 46.1% to levofloxacin, 3.8% to amoxicillin, and 21.1% to tetracycline. Our literature review also showed discrepancy of antimicrobial susceptibility test in strains isolated from different anatomical sites of the stomach. Heteroresistance H. pylori infection in developing countries is mostly due to infection with multiple H. pylori strains, while in developed countries it is due to microevolution of a single H. pylori strain in response to antibiotic pressure.

CONCLUSIONS

Heteroresistance H. pylori infection interferes with successful therapy and eventually can lead to the treatment failure. If a biopsy is taken from only one gastric site, resistant strains of H. pylori may be underestimated. Considering the role of heteroresistance H. pylori infection in treatment failure, it is very important for gastroenterologists to improve their knowledge about this fact. Regardingly, new guidelines should be developed and designed for the management and treatment of heteroresistance H. pylori infection.

New Strategy for the Detection and Treatment of Helicobacter pylori Infections in Primary Care Guided by a Non-Invasive PCR in Stool: Protocol of the French HepyPrim Study

Helicobacter pylori (Hp) infects half of the world population and is responsible for gastric, duodenal ulcers and gastric cancer. The eradication of Hp cures ulcers and prevents ulcer recurrences and gastric cancer. Antibiotic resistance of Hp, and particularly clarithromycin resistance, is the primary cause of treatment failure and is a major concern identified by the WHO as a high priority requiring research into new strategies. Treatments guided by the detection of antibiotic resistance have proven their medical and economical superiority. However, this strategy is severely hampered by the invasive nature of the fibroscopy, since antibiotic resistance detection requires gastric biopsies. The eradication of Hp involves primary care physicians. The objective of this study will be to evaluate the feasibility of a strategy for the management of Hp infection in primary care by a recently developed non-invasive procedure and its non-inferiority in eradication rates compared with the strategy recommended by the French National Authority of Health. The non-invasive procedure is a PCR on stool to detect Hp infection and mutations conferring resistance to clarithromycin allowing a treatment guided by the results of the PCR. We present the protocol of a prospective, multicenter, randomized, controlled interventional study in two arms.

Who Could Be Blamed in the Case of Discrepant Histology and Serology Results for Helicobacter pylori Detection?

BACKGROUND

Discrepancies between histology and serology results for Helicobacter pylori detection could be caused by a variety of factors, including a biopsy sampling error, expertise of the pathologist, natural loss of infection due to advanced atrophy, or a false-positive serology in the case of a previous infection, since antibodies may be present in blood following recovery from the infection.

AIMS

To identify true H. pylori-positive individuals in discrepant cases by serology and histology using real time polymerase chain reaction (RT-PCR) as a gold standard.

METHODS

Study subjects with discrepant histology and serology results were selected from the GISTAR pilot study data base in Latvia. Subjects having received previous H. pylori eradication therapy or reporting use of proton pump inhibitors, antibacterial medications, or bismuth containing drugs one month prior to upper endoscopy were excluded. We compared the discrepant cases to the corresponding results of RT-PCR performed on gastric biopsies.

RESULTS

In total, 97 individuals with discrepant results were identified: 81 subjects were serology-positive/histology-negative, while 16 were serology-negative/histology-positive. Among the serology-positive/histology-negative cases, 64/81 (79.0%) were false-positives by serology and, for the majority, inflammation was absent in all biopsies, while, in the serology-negative/histology-positive group, only 6.2% were proven false-positives by histology.

CONCLUSIONS

Among this high H. pylori prevalent, middle-aged population, the majority of discrepant cases between serology and histology were due to false positive-serology, rather than false-negative histology. This confirms the available evidence that the choice of treatment should not be based solely on the serological results, but also after excluding previous, self-reported eradication therapy.

Development and Validation of Multiplex Quantitative PCR Assay for Detection of Helicobacter pylori and Mutations Conferring Resistance to Clarithromycin and Levofloxacin in Gastric Biopsy

Aims and Objectives

More than half of the world's population is infected with Helicobacter pylori, which can cause chronic gastritis. WHO has regarded clarithromycin-resistant H. pylori as a high priority pathogen. Hence, accurate diagnosis and detection of clarithromycin- and levofloxacin-resistant H. pylori strains is essential for proper management of infection. The objective of this study was to develop and optimize multiplex quantitative PCR assay for detection of mutations associated with clarithromycin and levofloxacin resistance in H. pylori directly from the gastric biopsies.

Materials and Methods

Specific primers and probes were designed to amplify ureA and mutations in 23S rRNA and gyrA genes. Singleplex and triplex qPCR assays were optimized and the assay's sensitivities and specificities were determined. The optimized multiplex qPCR assay was performed on 571 gastric biopsies.

Results

In this study, 14.7% (84/571) of the gastric biopsies were positive for H. pylori by conventional methods and 23.8% (136/571) were positive by the ureA-qPCR with 96.4% sensitivity and 88.5% specificity, while the +LR and -LR were 8.72 and 0.04, respectively. The ureA-positive samples (n=136) were subjected to multiplex qPCR which detected A2142G and A2143G mutations in the 23S rRNA gene (20.6%, 28/136) conferring clarithromycin resistance and gyrA mutations N87K, N87I, D91N, and D91Y (11.8%, 16/136) leading to levofloxacin resistance. The sensitivity and specificity of qPCR of 23S rRNA gene were 100% and 98.7%, respectively, while 100% and 99.8% for qPCR of gyrA, respectively.

Conclusion

The effectiveness of this qPCR is that it is sensitive in detecting low bacterial load and will help in timely detection of clarithromycin- and levofloxacin-resistant strains, especially in case of mixed infections. Since it is culture independent, it can inform clinicians about antibiotics to be included in the first-line therapy, thereby improving the management of H. pylori infection at a much greater pace.

Effect of Statins on <b><i>Helicobacter pylori</i></b> Eradication Rate: A Systematic Review and Meta-Analysis

Statins have been used as adjuvants to standard treatment in order to increase the eradication rates of Helicobacter pylori infection. This study aimed to summarize the results of the efficacy of adding statins to standard treatments used for the eradication of H. pylori infection. We conducted a systematic search using a comprehensive combination of keywords in PubMed/MEDLINE, Web of Science, and Scopus to retrieve relevant studies from 1990 to 2020. The estimate of pooled relative risk (RR), as the effect measure, was calculated using random effects meta-analyses in Stata 14. We finally included 5 studies (all of them were randomized controlled trials). The meta-analysis of all studies showed that the pooled RR (95% confidence interval) was 1.03 (0.64–1.68) in the random effects model, which was not statistically significant. In other words, based on our meta-analysis, the addition of statins as an adjuvant therapy to the standard treatment regimens does not increase the rate of H. pylori eradication. However, further evidence is needed to confirm this result as the number of available studies was small.

A Retrospective Experience of Helicobacter pylori Histology in a Large Sample of Subjects in Northern Italy

Updated data about the prevalence of Helicobacter pylori (H. pylori) and its correlation with histological results are scarce. The aim of our study was to provide current data on the impact of H. pylori in a third-level endoscopy service. We performed a large, retrospective study analyzing the results of all histological samples of gastroscopy from the year 2019. In total, 1512 subjects were included. The prevalence of H. pylori was 16.8%. A significant difference between the prevalence in subjects born in Italy and those from eastern Europe, south America, or Africa was found (p < 0.0001, p = 0.006, and p = 0.0006, respectively). An association was found between H. pylori and active superficial gastritis (p < 0.0001). Current H. pylori and/or a previous finding of H. pylori was related to antral atrophy (p < 0.0001). Fifteen patients had low-grade dysplasia. There were no statistically significant associations with current or past H. pylori infection. One patient presented gastric cardia adenocarcinoma with regular gastric mucosa. One patient, H. pylori positive, was diagnosed with gastric signet ring cell adenocarcinoma in a setting of diffuse atrophy, without metaplasia.. Our study provides updated, solid (biopsy diagnosis and large population) data on the prevalence of H. pylori infection in a representative region of southern Europe.

Direct detection of Helicobacter pylori from biopsies of patients in Lagos, Nigeria using real-time PCR-a pilot study

Objective

Prompt diagnosis of Helicobacter pylori infection is essential for proper treatment and eradication of the pathogen because prolonged infection could lead to gastric cancer. Sensitive and cost effective diagnostic methods are key to guiding treatment options that will reduce mortality. This study was aimed at detecting H. pylori from biopsies of peptic ulcer patients. Real-time PCR using TaqMan and EvaGreen assays targeting 16S rRNA and ureA genes were used to detect H. pylori DNA extracted from 40 biopsy samples comprising 20 biopsies obtained from the antrum and 20 from the corpus of 20 patients undergoing endoscopy for duodenal ulcer investigation in Lagos, Nigeria.

Results

H. pylori was detected in 80% of the biopsy samples by combined cycle threshold (C_t) and melting temperature (T_m) values. Mean C_t value for ureA gene ranged from 21.40 to 37.53 and 22.71 to 35.44 for 16SrRNA gene. Average melting temperatures (T_m) of 81.57 and 82.90 °C among amplicons of ureA and 16S rRNA were observed respectively. H. pylori DNA was generally detected in biopsies collected from antrum and corpus. Real-time PCR in the diagnosis of H. pylori can be considered a simple, low cost and efficient alternative or addition to the gold standard.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05505-y.

Trend of changes in antibiotic resistance in Helicobacter pylori from 2013 to 2019: a multicentre report from Taiwan

BACKGROUND

Antibiotic resistance plays a crucial role in the treatment failure of Helicobacter pylori (H. pylori) infection. This study aimed to determine the trend of changes in the primary, secondary and tertiary antibiotic resistance of H. pylori in Taiwan over the last 7 years.

METHODS

We retrospectively analysed H. pylori-infected isolates from patients with primary resistance (n = 1369), secondary resistance (n = 196) and tertiary resistance (n = 184) from January 2013 to December 2019. The H. pylori strains were tested for susceptibility to amoxicillin, clarithromycin, levofloxacin, metronidazole and tetracycline using the Epsilometer test method.

RESULTS

A progressively higher primary resistance rate was observed for clarithromycin (11.8-20.4%, p = 0.039 in χ2 test for linear trend), levofloxacin (17.3-38.8%, p < 0.001) and metronidazole (25.6-42.3%, p < 0.001) among naïve patients who received first-line eradication therapy. The dual primary resistance to clarithromycin and metronidazole also progressively increased in a linear trend (2.4-10.4%, p = 0.009). For secondary resistance, an increase was observed for levofloxacin (30.5-64.7%, p = 0.006) and metronidazole (40.5-77.4%, p < 0.001). For tertiary resistance, the observed increase was even more significant for levofloxacin (65.9-100.0%, p = 0.106) and metronidazole (44.4-88.2%, p < 0.001). The resistance to amoxicillin and tetracycline remained very low in Taiwan regardless of primary, secondary and tertiary resistance.

CONCLUSION

Primary, secondary and tertiary antibiotic resistance to clarithromycin, levofloxacin and metronidazole for H. pylori has been increasing in Taiwan since 2013. Treatment should be targeted for eradication success rates of more than 90%. Third-line treatment should be based on antibiotic susceptibility.