Helicobacter pylori and Its Antibiotic Heteroresistance: A Neglected Issue in Published Guidelines

Current status of Helicobacter pylori resistance to clarithromycin and levofloxacin in Vietnam: Results from molecular analysis of gastric biopsy specimens

OBJECTIVES

The management of Helicobacter pylori in Vietnam is becoming progressively more difficult due to increasing antibiotic resistance, particularly to clarithromycin (CLR) and levofloxaxin (LVX). In Vietnam, the selection of an H. pylori eradication regimen is predominantly based on empirical evidence. However, molecular analysis aimed at identifying H. pylori antibiotic-resistant genotypes is a promising method in antibiotic susceptibility testing. In this study, we aimed to determine the rates of genotypic H. pylori resistance to CLR and LVX by using DNA strip technology in Vietnam.

METHODS

We performed DNA-strip technology-based testing on 112 patients with H. pylori-positive gastroduodenal diseases to detect 23S rRNA and gyrA mutations.

RESULTS

Helicobacter pylori genotypic resistance to CLR and LVX was evident in 81.3% and 53.6% of the patients, respectively, and dual resistance was observed in 48.2%. The 23S rRNA A2142G and A2143G mutations accounted for 1.8% and 79.5% of cases, respectively. The gyrA N87K, D91N, D91G, and D91Y mutations were present in 37.5%, 11.6%, 5.4%, and 5.4% of patients, respectively. All four gyrA mutations were observed in both the naïve and failure patients. We further found an association between the 23S rRNA A2143G mutation and a history of CLR use as well as between the gyrA N87K mutation and a history of LVX use.

CONCLUSIONS

We found a very high prevalence of H. pylori resistance to CLR and LVX and dual resistance to these antibiotics in Vietnam. The application of molecular assays is feasible and may improve the management of H. pylori infection in Vietnam.

Analysis of Helicobacter pylori resistance in patients with different gastric diseases

Helicobacter pylori (H. pylori) resistance is the most important risk factor for eradication failure. However, in most regions, antibiotic resistance rates of H. pylori in patients with different types of gastric mucosal lesions are still unclear. An 8-year clinical retrospective cohort study involving 2847 patients was performed. In this study, we first summarized and compared the resistance status of H. pylori in different years, ages, sexes, and gastric diseases. The resistance profiles of amoxicillin (AMX), clarithromycin (CLR), levofloxacin (LVX) and furazolidone (FR) and their changing trends in the clinic were described. Then, multiple antibiotic resistance in different gastric diseases and years were described and compared. The relationship between proton pump inhibitor (PPI) medication history and antibiotic resistance in H. pylori was also explored. Finally, an antibiotic resistance risk model was constructed for clinical resistance risk prediction. The overall resistance rates of AMX, CLR, LVX and FR in gastric diseases were 8.18%, 38.11%, 43.98%, and 13.73%, respectively. The mono resistance, double resistance, triple resistance, and quadruple resistance rates were 30.17%, 25.96%, 6.46%, and 0.63%, respectively. Compared with the period from 2014 to 2016, the rates of mono-resistance and multiple resistance all showed relatively downward trends in the past 5 years. Factors including age, sex, type of gastric lesions and recent PPI treatment history are associated with the antibiotic resistance rate of H. pylori. Atrophic gastritis is an important clinical feature of high-risk antibiotic resistance in H. pylori-infected patients. Patients with atrophic gastritis have higher risk of resistant strains infection. In this study, our data provide the association between antibiotic resistance of H. pylori and gastritis pattern, which indicate the higher risk of resistant strain infection if the patients with atrophic gastritis, PPI history and older age.

Revolution of Helicobacter pylori treatment

Helicobacter pylori infection is a major global health concern, and its management has witnessed a revolutionary shift with the emergence of antibiotic resistance. In this review, I explore the mechanisms of H. pylori antibiotic resistance and highlight the critical need for susceptibility-based eradication treatments. The increasing prevalence of antibiotic-resistant strains requires innovative approaches to combat this resilient pathogen. I also delve into the importance of mass screening as a preventive strategy for early detection and intervention, describing my experience in Bhutan. Additionally, I explore promising alternatives, such as vaccination. The aim of this review is to provide insight into the evolving landscape of H. pylori treatment and highlight the need for a paradigm shift in the approach to combating this persistent bacterial infection.

Antibiotic resistance of Helicobacter pylori in Chinese children: A multicenter study from 2016 to 2023

BACKGROUND

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children.

MATERIALS AND METHODS

This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method.

RESULTS

Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole.

CONCLUSIONS

The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.

A Mini-review on Helicobacter pylori with Gastric Cancer and Available Treatments

Helicobacter pylori (H. pylori) is the most thoroughly researched etiological component for stomach inflammation and malignancies. Even though there are conventional recommendations and treatment regimens for eradicating H. pylori, failure rates continue to climb. Antibiotic resistance contributes significantly to misdiagnoses, false positive results, and clinical failures, all of which raise the chance of infection recurrence. This review aims to explore the molecular mechanisms underlying drug resistance in H. pylori and discuss novel approaches for detecting genotypic resistance. Modulation of drug uptake/ efflux, biofilm, and coccoid development. Newer genome sequencing approaches capable of detecting H. pylori genotypic resistance are presented. Prolonged infection in the stomach causes major problems such as gastric cancer. The review discusses how H. pylori causes stomach cancer, recent biomarkers such as miRNAs, molecular pathways in the development of gastric cancer, and diagnostic methods and clinical trials for the disease. Efforts have been made to summarize the recent advancements made toward early diagnosis and novel therapeutic approaches for H. pylori-induced gastric cancer.

Mixed (multiple-genotype) Helicobacter pylori infections in Bulgarian patients

The aim of the study was to evaluate the frequency and characteristics of mixed (multiple-genotype) Helicobacter pylori infections (MGIs) in 155 Bulgarian symptomatic patients (21 children and 134 adults). MGIs were common (36.1%), including double-strain (34.8%) and triple-strain infections (1.3%). None of the 8 ulcer patients harbored multiple subtypes. We detected 18 multiple allelic combinations, of which the most frequent subtypes (17.4%) were vacA s1as2 and vacA s1cs2. The 2 patients with triple-strain infections had vacA s1bs1cs2i1i2/iceA1A2 and vacA s1as1cs2 subtypes. They were both adult men with chronic gastritis and both were examined in 2022. The prevalence of MGIs (51.7%) was 2-fold higher in 2020 to 2022 than in 2015 to 2019 (26.3%). Putative factors for the increase may be the patient's characteristics and COVID-19 pandemic-associated factors. MGI rates corresponded to the high infection seroprevalence (72.4% in 2011) in Bulgaria. The evolution and clinical importance of mixed H. pylori infections merit extensive evaluation.

Dysbiosis by Eradication of Helicobacter pylori Infection Associated with Follicular Gastropathy and Pangastropathy

Dysbiosis plays an important role in the development of bacterial infections in the gastric mucosa, particularly Helicobacter pylori. The international guidelines for the treatment of H. pylori infections suggest standard triple therapy (STT). Nevertheless, because of the increasing resistance rates to clarithromycin, metronidazole has been widely considered in several countries. Unfortunately, the non-justified administration of antibiotics induces dysbiosis in the target organ. We characterized the gastric microbiota of patients diagnosed with follicular gastropathy and pangastropathy attributed to H. pylori infection, before and after the administration of STT with metronidazole. Dominant relative abundances of Cutibacterium were observed in pre-treatment patients, whereas H. pylori was observed at <11%, suggesting the multifactor property of the disease. The correlation of Cutibacterium acnes and H. pylori with gastric infectious diseases was also evaluated using quantitative real-time polymerase chain reaction. The dominance of C. acnes over H. pylori was observed in gastritis, gastropathies, and non-significant histological alterations. None of the microorganisms were detected in the intestinal metaplasia. Post-treatment alterations revealed an increase in the relative abundances of Staphylococcus, Pseudomonas, and Klebsiella. Non-H. pylori gastrointestinal bacteria can be associated with the initiation and development of gastric diseases, such as pathobiont C. acnes.

Antibiotic resistance, heteroresistance, and eradication success of Helicobacter pylori infection in children

BACKGROUND

Antibiotic resistance is a well-known factor of Helicobacter pylori eradication failure. Heteroresistance indicates the coexistence of resistant and susceptible strains and might lead to underestimating antimicrobial resistance. This study aims to evaluate the susceptibility profile, the frequency of heteroresistance of H. pylori strains, and their effect on eradication success in a pediatric population.

MATERIALS AND METHODS

Children aged 2-17 years who underwent an upper gastrointestinal endoscopy from 2011 to 2019 with positive H. pylori status were included. Susceptibility was measured by disk diffusion and E-test. The difference in susceptibility profiles between isolates from the antrum and the corpus was used to detect heteroresistance. For those who received eradication treatment, we evaluated eradication rate and factors affecting treatment success.

RESULTS

Inclusion criteria were met by 565 children. Strains susceptible to all antibiotics were detected in 64.2%. Primary resistance rates for clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), tetracyclin (TET), and amoxicillin (AMO) were 11%, 22.9%, 6.9%, 0.4%, and 0% and secondary resistance rates were 20.4%, 29.4%, 9.3%, 0%, and 0%. Heteroresistance was present in untreated children in 2%, 7.1%, 0.7%, 0.7%, and 0% for CLA, MET, LEV, TET, and AMO. First-line eradication rates were 78.5% in intention-to-treat (ITT), 88.3% in full-analysis-set (FAS), and 94.1% in per-protocol (PP). Factors affecting eradication success were the duration of treatment when the triple-tailored treatment was used, the number of daily doses of amoxicillin administered, and the patient's adherence to treatment.

CONCLUSIONS

This study shows the presence of relatively low primary resistance rates for H. pylori isolates but demonstrates the presence of heteroresistance in our population. Routine biopsies from the antrum and corpus must be considered for susceptibility testing to allow tailored treatments and increase eradication rates. Treatment success is affected by treatment choice, correct dosing of medications, and adherence. All these factors should be considered when evaluating the efficacy of an eradication regimen.

Optimizing Helicobacter pylori Treatment: An Updated Review of Empirical and Susceptibility Test-Based Treatments

As the rate of discovery of drug-resistant Helicobacter pylori cases increases worldwide, the relevant societies have updated their guidelines for primary eradication regimens. A promising strategy against drug-resistant H. pylori is tailored therapy based on the results of an antibiotic susceptibility test; however, it is difficult to apply this strategy to all cases. Although culture-based antibiotic susceptibility tests can assess resistance to any antimicrobial agent, their greatest disadvantage is the time required to draw a conclusion. In contrast, molecular-based methods, such as polymerase chain reaction, can rapidly determine the presence of resistance, although a single test can only test for one type of antimicrobial agent. Additionally, the limited availability of facilities for molecular-based methods has hindered their widespread use. Therefore, low-cost, minimally invasive, simple, and effective primary regimens are needed. Several studies have compared the efficacy of the latest primary eradication regimens against that of tailored therapies, and their results have shaped guidelines. This article reviews the latest research on empirical and tailored treatments for H. pylori infections. Evidence for the superiority of tailored therapy over empirical therapy is still limited and varies by region and treatment regimen. A network meta-analysis comparing different empirical treatment regimens showed that vonoprazan triple therapy provides a superior eradication effect. Recently, favorable results towards vonoprazan dual therapy have been reported, as it reached eradication levels similar to those of vonoprazan triple therapy. Both vonoprazan dual therapy and tailored therapy based on antibiotic susceptibility tests could contribute to future treatment strategies.

Primary antibiotic resistance in Helicobacter pylori in China: a systematic review and meta-analysis

OBJECTIVES

The incidence of Helicobacter pylori (HP) is 25-50% in developed countries and 80% in developing countries, including 56.2% in China. However, antibiotic resistance of HP is a threat to HP control. The purpose of this study was to comprehensively evaluate primary drug resistance of HP in China.

METHODS

The full text of reports of the primary antibiotic resistance prevalence of HP was obtained from multiple databases (PubMed, Web of Science, Evimed, Cochrane Library, and China National Knowledge Internet). Review Manager 5.2 was adopted for meta-analysis, sensitivity analysis, and bias analysis. The Newcastle-Ottawa Scale was used to assess the article quality.

RESULTS

In total, 38804 HP samples from 22 trials were extracted. The results suggested that the overall prevalence of amoxicillin, clarithromycin, metronidazole, and levofloxacin resistance among HP in adults was as follows: mean difference (MD) = 1.35%, 95% confidence interval (CI) [1.03%, 1.68%]; MD = 23.76%, 95% CI [20.23%, 27.3%]; MD = 69.32%, 95% CI [64.85%, 73.8%]; and MD = 29.45%, 95% CI [4.90, 176.96], respectively. From the results of sensitivity and publication bias, we find that these results are robust and had little publication bias.

CONCLUSION

Our research showed that in China, the prevalence of HP resistance to primary antibiotics warrants attention, especially with regard to metronidazole, levofloxacin, and clarithromycin.

Factors associated with treatment failure, and possible applications of probiotic bacteria in the arsenal against Helicobacter pylori

INTRODUCTION

Helicobacter pylori is a widespread helical Gram-negative bacterium, which causes a variety of stomach disorders, such as peptic ulcer, chronic atrophic gastritis, and gastric cancer. This microbe frequently colonizes the mucosal layer of the human stomach and survives in the inhospitable microenvironment, by adapting to this hostile milieu.

AREAS COVERED

In this extensive review, we describe conventional antibiotic treatment regimens used against H. pylori including, empirical, tailored, and salvage therapies. Then, we present state-of-the-art information about reasons for treatment failure against H. pylori. Afterward, the latest advances in the use of probiotic bacteria against H. pylori infection are discussed. Finally, we propose a polymeric bio-platform to provide efficient delivery of probiotics for H. pylori infection.

EXPERT OPINION

For effective probiotic delivery systems, it is necessary to avoid the early release of probiotics at the acidic stomach pH, to protect them against enzymes and antimicrobials, and precisely target H. pylori bacteria which have colonized the antrum area of the stomach (basic pH).

Evolution of Helicobacter pylori Resistance to Antibiotics: A Topic of Increasing Concern

Antibiotic resistance among Helicobacter pylori strains is the major cause of eradication failure. Resistance prevalence is dynamic and can greatly vary among countries over the years. We revealed H. pylori resistance trends for five antibiotics in 14 countries through articles predominantly published in 2018-2022, since the latest data can best show the most recent trends in resistance evolution. Amoxicillin resistance generally exhibited no evolution, yet it increased in Bulgaria, Iran, China, and Vietnam. Metronidazole resistance exhibited different trends, including an increase, a decrease and no evolution in six, three, and five studies, respectively. Clarithromycin resistance increased in Australia, Belgium, Bulgaria, Italy, Iran, and Taiwan, but remained stable in France, Spain, Russia, China, Chile, and Colombia. Tetracycline resistance was low and stable except in Iran. Levofloxacin resistance increased in four European and six other countries/regions, without significant increases in France, Spain, and Chile. In Chile, triple resistance also increased. In countries such as France and Spain, resistance to most antibiotics was stabilized, while in Bulgaria, Belgium, Iran and Taiwan, resistance to three or more agents was reported. Use of non-recommended regimens, national antibiotic consumption, patient's compliance, host factors, strain virulence, migrations, and azithromycin overuse during the COVID-19 pandemic can influence resistance evolution. New drugs, eradication regimens and diagnostic methods, such as next-generation sequencing can improve H. pylori infection control.

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.

Heteroresistance to clarithromycin and metronidazole in patients with a Helicobacter pylori infection: a systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection.

MATERIAL AND METHODS

A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent.

RESULTS

A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I² = 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I² = 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype.

CONCLUSION

The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.

Chitosan-curcumin complexation to develop functionalized nanosystems with enhanced antimicrobial activity against hetero-resistant gastric pathogen

With the apparent stagnation in the antibiotic discovery and the propagation of multidrug resistance, Helicobacter pylori associated gastric infections are hard to eradicate. In pursuance of alternative medicines, in this study, covalent modification of chitosan (CS) polymer with curcumin (Cur) was accomplished. Proton Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy elucidated the covalent interaction between Cur and CS with characteristic peak of imine functional group (C=N). Scanning Electron Microscopy provided visual proof for surface topology, while size and zeta potential values further affirmed the development of curcumin functionalized chitosan nanosystems (Cur-FCNS). The complexation efficiency of CS with Cur was found as 70 ± 3% at an optimal ratio of 5:1 for CS and Cur, respectively. Cur-FCNS developed with ionic gelation and ultrasonication method demonstrated synergistic anti-H. pylori activity in growth-kinetics and anti-biofilm assays, which was superior to free Cur and even chitosan nanosystems. Under simulated gastric conditions, Cur-FCNS revealed cumulative-release of only 16 ± 0.8% till 40 h, which indicated its improved stability to interact with H. pylori. In silico findings affirmed high binding affinity of Cur-FCNS with multiple bacterial virulence factors. Thus, our results affirmed the exceptional potential of Cur-FCNS as next-generation alternative-medicine to treat resistant H. pylori.

Innate Lymphoid Cells and Natural Killer Cells in Bacterial Infections: Function, Dysregulation, and Therapeutic Targets

Infectious diseases represent one of the largest medical challenges worldwide. Bacterial infections, in particular, remain a pertinent health challenge and burden. Moreover, such infections increase over time due to the continuous use of various antibiotics without medical need, thus leading to several side effects and bacterial resistance. Our innate immune system represents our first line of defense against any foreign pathogens. This system comprises the innate lymphoid cells (ILCs), including natural killer (NK) cells that are critical players in establishing homeostasis and immunity against infections. ILCs are a group of functionally heterogenous but potent innate immune effector cells that constitute tissue-resident sentinels against intracellular and extracellular bacterial infections. Being a nascent subset of innate lymphocytes, their role in bacterial infections is not clearly understood. Furthermore, these pathogens have developed methods to evade the host immune system, and hence permit infection spread and tissue damage. In this review, we highlight the role of the different ILC populations in various bacterial infections and the possible ways of immune evasion. Additionally, potential immunotherapies to manipulate ILC responses will be briefly discussed.

Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications

Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.

Efficacy of Clarithromycin Depends on the Bacterial Density in Clarithromycin-Heteroresistant Helicobacter pylori Infections: An In Situ Detected Susceptibility and Quantitative Morphometry-Based Retrospective Study

The global rise in clarithromycin (Cla) resistance is considered to be the main contributor of Helicobacter pylori (Hp) eradication failures. In nearly half of the Cla-resistant Hp infections, Cla-susceptible bacteria are simultaneously present with the Cla-resistant ones (Cla-heteroresistance). The proportion of resistant bacteria in the bacterial population (R-fraction) and its predictive role for the use of Cla-based therapies in Cla-heteroresistant infections has not yet been investigated. Our retrospective study analyzed gastric biopsy samples of 62 Hp-positive patients with Cla-heteroresistant infection. Fluorescence In Situ Hybridization technique was used to visualize the coexistence of resistant and susceptible bacteria within one tissue sample. R-fraction was quantified on multichannel microimages by digital morphometry. Resistant bacteria had a patchy distribution within the whole bacterial population causing high diversity among the investigated areas. Patients were subdivided into two major groups according to whether a Cla-based eradication attempt was conducted before or after the biopsy sampling. R-fraction was significantly lower among cases having only one previous Cla-based eradication attempt vs. those that had multiple previous eradications, including at least one Cla-containing therapy (0.41 vs. 0.89, p = 0.0308). Majority of the patients without previous eradication attempt had successful eradication with Cla-containing regimen (59.26%), verified by a negative ¹³C-urea breath test or control biopsy. Multivariable model indicated that the therapeutic outcome using Cla-based regimens depended on the bacterial density rather than the R-fraction. Our study raises the potential use of Cla-containing eradication therapies in certain Cla-heteroresistant Hp infections, taking into account the possible predictive role of bacterial density.

Modified bismuth quadruple therapy with low-dose metronidazole as first-line therapy for Helicobacter pylori infection

BACKGROUND

Bismuth-containing quadruple therapy is an effective alternative first-line therapy for Helicobacter pylori infection. We evaluated the efficacy and safety of a modified twice-a-day bismuth quadruple regimen (BQT-2) with low-dose (1000 mg total) metronidazole as first-line therapy for the eradication of H pylori.

MATERIALS AND METHODS

In this prospective pilot study, patients diagnosed with H pylori infection and naïve to eradication therapy were included. The modified BQT-2 therapy consisted of rabeprazole 20 mg, amoxicillin 1 g, metronidazole 500 mg, and tripotassium dicitrato bismuthate 600 mg (elemental bismuth 240 mg) twice daily, given 30 minutes before morning and evening meals for 14 days. H pylori eradication was assessed by ¹³ C-urea breath test conducted at least 4 weeks after therapy completion.

RESULTS

In 66 patients who received the modified BQT-2 regimen, the compliance rate was 100% and the H pylori eradication rate was 77.3%. H pylori was successfully cultured in 50 (75.8%) patients. The resistance rates to metronidazole and clarithromycin were 30.0% and 22.0%, respectively. Eradication rates were not significantly different according to the resistance to metronidazole (metronidazole-susceptible: 74.3% [26/35], metronidazole-resistant: 73.3% [11/15]; P > .99). Most of the adverse events were mild, with 20 (30%) patients developing nausea, epigastric soreness, loose stool, asthenia, skin rash, dizziness, taste perversion, headache, or dyspepsia.

CONCLUSIONS

Twice-a-day modified BQT-2 regimen with low-dose metronidazole was suboptimal as an alternative first-line therapy for eradicating H pylori, despite high patient compliance.

Novel in vitro and in vivo anti-Helicobacter pylori effects of pomegranate peel ethanol extract

BACKGROUND AND AIM

Interest in plants with antimicrobial properties has been revived due to emerging problems associated with using antibiotics to eradicate Helicobacter pylori. Accordingly, this study aims to assess the antibacterial effects of Punica granatum and the possible synergistic effect of its extract along with metronidazole against H. pylori.

MATERIALS AND METHODS

Pomegranate peel ethanol extracts (PPEE) was tested against a control strain of H. pylori (NCTC 11916) in vitro and in vivo in female Wistar rats. Moreover, the synergistic effect of PPEE in combination with metronidazole was tested in vitro.

RESULTS

The PPEE exhibited a remarkable activity against H. pylori with a minimum inhibitory concentration (MIC) of 0.156 mg/mL. Furthermore, the extract exhibited a pronounced urease inhibitory activity (IC50 ~6 mg/mL) against the tested strain. A synergistic effect between PPEE and metronidazole was also observed (fractional inhibitory concentrations <0.5). Oral treatment of rats with PPEE for 8 days produced a significant reduction in H. pylori gastritis and a significant decrease in both lymphocytic and positive chronicity.

CONCLUSION

Pomegranate extract is probably safe and represents a potential alternative and complementary therapy for reducing H. pylori associated with gastric ulcers.

Controversias en cirugía: Erradicación del Helicobacter pylori ¿Terapia a todos o según indicaciones usuales?

La infección por Helicobacter pylori (H. pylori), es la infección bacteriana crónica más frecuente de la raza humana, afecta al 50 % de la población mundial y, por lo menos, al 80 % de la población colombiana. Esta bacteria es reconocida desde hace más de 15 años como un carcinógeno tipo I. De acuerdo con las indicaciones del Consenso de “Maastricht V” esta infección debe ser buscada y tratada en los pacientes con úlcera péptica activa, Linfoma MALT (por sus siglas en inglés, mucosa associated lymphoid tissue), cáncer gástrico temprano, púrpura que presenten síntomas dispépticos crónicos y usuarios crónicos de AINES. Debido al papel que tiene en la fisiopatología del cáncer gástrico, nace la iniciativa de realizar una búsqueda activa del H. pylori y erradicarlo en todas las personas, incluyendo aquellas asintomáticas en países con alta incidencia de esta neoplasia. Existen diversas publicaciones alrededor del mundo que así lo sugieren, mostrando resultados con impacto positivo en el curso y progresión de la enfermedad, sobre todo en las etapas más tempranas de la infección. Sin embargo, otros autores resaltan la creciente problemática de la resistencia bacteriana, y demuestran que el peso estadístico y los diferentes análisis de los estudios disponibles en la actualidad tienen poca validez para dar una recomendación extendida al paciente asintomático. Se cuestiona que tal vez, estamos utilizando las estrategias inadecuadas para manejar una situación de salud pública, ya que estamos enfocados en impactar a cada individuo con terapias antibióticas complejas, en vez de a la población en general con políticas de salud pública.

Correlation Analysis of Helicobacter pylori Infection and Digestive Tract Symptoms in Children and Related Factors of Infection

BACKGROUND

To analyze the correlation between Helicobacter pylori infection and digestive tract symptoms in children and other related factors, and to explore the risk factors of H. pylori infection in children and the expression of inflammatory factors in H. pylori-positive and H. pylori-negative children.

METHODS

Overall, 234 children with H. pylori test in Xuzhou Children's Hospital, Xuzhou Medical University (Xuzhou, China) were enrolled. Among them, 73 children were H. pylori-positive and 161 were H. pylori-negative. The expression levels of cytokines interleukin-8 (IL-8), interleukin-18 (IL-18) and interferon-γ (IFN-γ) in H. pylori-positive and H. pylori-negative children were determined by ELISA. The correlation between H. pylori-positive and general data, digestive tract symptoms, other clinical symptoms, living habits, eating habits, family history and other related factors was statistically analyzed. Multivariate Logistic regression analysis was used to analyze the independent risk factors of H. pylori infection in children.

RESULTS

Family monthly income, inattentive eating, sharing toothbrushes and cups, gnawing fingers, eating fried food, drinking raw water, eating smoked and pickled food, father suffering from gastropathy and mother suffering from gastropathy were independent risk factors for H. pylori infection in children. The most common digestive tract symptoms of children with H. pylori infection were abdominal pain, accompanied by one or more clinical symptoms. The expression levels of IL-8, IL-18 and IFN-γ in H. pylori-positive children were significantly higher than those in H. pylori-negative children.

CONCLUSION

Prevention of H. pylori infection in children is helpful for healthy growth of children, and cytokines IL-8, IL-18, IFN-γ have the potential to be used as biomarkers for diagnosis of H. pylori-positive children.

Innate Lymphoid Cells: Important Regulators of Host-Bacteria Interaction for Border Defense

Innate lymphoid cells (ILCs) are a recently discovered type of innate immune lymphocyte. They include three different groups classified by the nature of the transcription factors required for their development and by the cytokines they produce. ILCs mainly reside in tissues close to the mucosal barrier such as the respiratory and gastrointestinal tracts. Due to their close proximity to the mucosal surface, ILCs are exposed to a variety of both commensal and pathogenic bacteria. Under non-pathological conditions, ILCs have been shown to be important regulators for the maintenance of tissue homeostasis by mutual interactions with the microbiome. Besides these important functions at homeostasis, several studies have also provided emerging evidence that ILCs contribute to defense against pathogenic bacterial infection by responding rapidly to the pathogens as well as orchestrating other immune cells. In this review, we summarize recent advances in our understanding of the interactions of ILCs and bacteria, with special focus on the function of the different ILC subsets in bacterial infections.

Re-assessment of the disk diffusion technique for routine antimicrobial susceptibility testing for Helicobacter pylori

BACKGROUND

The aim of this study was to assess the disk diffusion technique against E-test as a routine antibiotic susceptibility testing method for Helicobacter pylori.

MATERIALS AND METHODS

Susceptibilities of 301 H pylori clinical isolates were simultaneously profiled by E-test and disk diffusion method for levofloxacin (5-μg disk), clarithromycin (15-μg disk), metronidazole (5-μg disk), amoxicillin (10-μg disk), and tetracycline (30-μg disk). Furazolidone susceptibility was evaluated using a 100-μg disk only. The correlation between MICs by E-test and inhibition zone diameters by disk diffusion was assessed by linear regression analysis.

RESULTS

Correlation between inhibition zone diameters and MICs was found for levofloxacin (r = -.932), clarithromycin (r = -.894), and to a minor extent metronidazole (r = -.820). Using the linear regression analysis, the inhibition zone diameter breakpoints were calculated to be 29 mm for levofloxacin, 41 mm for clarithromycin, and 15 mm for metronidazole corresponding to the EUCAST-recommended MIC breakpoints. The susceptibility agreement between E-test and disk diffusion for levofloxacin, clarithromycin, and metronidazole was 98.6%, 96.0%, and 96.7%, respectively. The inhibition zone diameters recorded for the amoxicillin, tetracycline, and furazolidone were large (approximately 60 mm in mean), and a poor correlation was found between inhibition zone diameters and MICs for amoxicillin (r = -.594) and tetracycline (r = -.490).

CONCLUSIONS

The disk diffusion can be used as a routine H pylori susceptibility testing method for levofloxacin, clarithromycin, and metronidazole in clinical practice under the described technical conditions. The use of disk diffusion for amoxicillin, tetracycline, and furazolidone susceptibility testing needs to be further studied.

Next-Generation Sequencing of the Whole Bacterial Genome for Tracking Molecular Insight into the Broad-Spectrum Antimicrobial Resistance of Helicobacter pylori Clinical Isolates from the Democratic Republic of Congo

Antimicrobial susceptibility testing (AST) is increasingly needed to guide the Helicobacter pylori (H. pylori) treatment but remains laborious and unavailable in most African countries. To assess the clinical relevance of bacterial whole genome sequencing (WGS)-based methods for predicting drug susceptibility in African H. pylori, 102 strains isolated from the Democratic Republic of Congo were subjected to the phenotypic AST and next-generation sequencing (NGS). WGS was used to screen for the occurrence of genotypes encoding antimicrobial resistance (AMR). We noted the broad-spectrum AMR of H. pylori (rates from 23.5 to 90.0%). A WGS-based method validated for variant discovery in AMR-related genes (discovery rates of 100%) helped in identifying mutations of key genes statistically related to the phenotypic AMR. These included mutations often reported in Western and Asian populations and, interestingly, several putative AMR-related new genotypes in the pbp1A (e.g., T558S, F366L), gyrA (e.g., A92T, A129T), gyrB (e.g., R579C), and rdxA (e.g., R131_K166del) genes. WGS showed high performance for predicting AST phenotypes, especially for amoxicillin, clarithromycin, and levofloxacin (Youden's index and Cohen's Kappa > 0.80). Therefore, WGS is an accurate alternative to the phenotypic AST that provides substantial decision-making information for public health policy makers and clinicians in Africa, while providing insight into AMR mechanisms for researchers.