Third-line and rescue therapy for refractory Helicobacter pylori infection: A systematic review

Novel DNA gyrase mutations in levofloxacin-resistant Helicobacter pylori isolates from southern Vietnam

BACKGROUND

The escalating antibiotic resistance in Helicobacter pylori (H. pylori) has become a significant concern in the management of infections. This study aimed to investigate the mutations associated with levofloxacin resistance in H. pylori isolated from southern Vietnam.

METHODS

Levofloxacin-resistant H. pylori strains were isolated from peptic ulcer patients and DNA sequencing of DNA gyrase (gyrA and gyrB) genes was performed.

RESULTS

We found that 97 % of resistant isolates bearing at least one mutation in GyrA and 32.3 % had a simultaneous mutation in GyrB. Additionally, we identified three previously known mutations, G85C (1.5 %), N87 (34.3 %), and D91 (14.9 %), within the quinolone-resistance-determining region (QRDR) region of GyrA, which confer resistance through natural transformation and were the most prevalent in our study. Notably, we demonstrated a mutation (A88V MIC 4 μg/mL) in GyrA and four novel mutations (E422R MIC 16 μg/mL, A426G MIC 32 μg/mL, S429E MIC 4 μg/mL, and P443A MIC 4 μg/mL) in GyrB, belonging to the QRDR. Additionally, several mutations outside the QRDR were observed, including R190K (16.4 %), P219A/G (13.4 %), L45F (9 %), P220E (6 %), Y28I (4.5 %), A27L (3 %) in GyrA, and S457A (7.5 %), A382F (5.9 %), L389F (4.5 %), D412R (1.5 %), L460P (1.5 %), I482V (1.5 %), and L518E (1.5 %) that have not been documented in any previous studies and were not functionally validated.

CONCLUSION

These results highlight the high genetic diversity and prevalence of levofloxacin-resistant H. pylori strains in southern Vietnam and provide valuable insights into levofloxacin resistance mechanisms for future diagnostic and treatment advancements.

Efficacy and Safety of Vonoprazan in Dual/Triple/Quadruple Regimens Both in First-Line and Rescue Therapy for Helicobacter pylori Eradication: A Systematic Review With Meta-Analysis

BACKGROUND

The efficacy of Helicobacter pylori (H. pylori) eradication therapies encompassing one or more antibiotics and a proton pump inhibitor (PPI) has lately decreased. Vonoprazan (VPZ), a potassium-competitive acid blocker, provides higher gastric acid suppression than PPIs. We performed a meta-analysis evaluating the efficacy and safety of VPZ in H. pylori eradication therapies.

METHODS

Studies were searched in PubMed, Embase, and the Cochrane Library up to June 2023. Efficacy was evaluated by intention-to-treat analysis. Data were combined by meta-analyzing risk differences (RD). Heterogeneity was evaluated by subgrouping.

RESULTS

Seventy-seven studies (24 randomized clinical trials) evaluated 44,162 patients (22,297 receiving VPZ and 21,865 PPIs). Overall VPZ efficacy was 88% (95% CI = 87%-90%): 86%, 88%, and 94% for dual/triple/quadruple-VPZ-containing therapies. VPZ efficacy was 87% (86%-89%) in first-line and 90% (87%-93%) in rescue therapy. VPZ performed better than PPIs in treatment-naïve patients (87% vs. 70%; RD = 0.13, 95% CI = 0.11-0.15) and when using triple regimens. No significant differences were observed in rescue and quadruple therapies. In patients with clarithromycin-resistant infection, VPZ-based therapies demonstrated an 81% efficacy (76%-85%), surpassing PPIs (76% vs. 40%; RD = 0.33, 95% CI = 0.24-0.43). For clarithromycin-susceptible strains, VPZ efficacy was 92% (89%-95%), similar to PPIs. VPZ adverse events rate was 19% (16%-21%), comparable to PPI-based regimens (18% vs. 13%, respectively; RD = 0.00, 95% CI = -0.01 to 0.02, p = 0.57).

CONCLUSIONS

The efficacy of VPZ-based regimens was over 85% in all treatment combinations. In treatment-naïve and clarithromycin-resistant patients, VPZ performed better than PPIs. In rescue therapy, in clarithromycin-susceptible patients or when quadruple regimens were prescribed, this advantage was not confirmed. Tolerability was similar in both regimens.

ACG Clinical Guideline: Treatment of Helicobacter pylori Infection

ABSTRACT

Helicobacter pylori is a prevalent, global infectious disease that causes dyspepsia, peptic ulcer disease, and gastric cancer. The American College of Gastroenterology commissioned this clinical practice guideline (CPG) to inform the evidence-based management of patients with H. pylori infection in North America. This CPG used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to systematically analyze 11 Population, Intervention, Comparison, and Outcome questions and generate recommendations. Where evidence was insufficient or the topic did not lend itself to GRADE, expert consensus was used to create 6 key concepts. For treatment-naive patients with H. pylori infection, bismuth quadruple therapy (BQT) for 14 days is the preferred regimen when antibiotic susceptibility is unknown. Rifabutin triple therapy or potassium-competitive acid blocker dual therapy for 14 days is a suitable empiric alternative in patients without penicillin allergy. In treatment-experienced patients with persistent H. pylori infection, "optimized" BQT for 14 days is preferred for those who have not been treated with optimized BQT previously and for whom antibiotic susceptibility is unknown. In patients previously treated with optimized BQT, rifabutin triple therapy for 14 days is a suitable empiric alternative. Salvage regimens containing clarithromycin or levofloxacin should only be used if antibiotic susceptibility is confirmed. The CPG also addresses who to test, the need for universal post-treatment test-of-cure, and the current evidence regarding antibiotic susceptibility testing and its role in guiding the choice of initial and salvage treatment. The CPG concludes with a discussion of proposed research priorities to address knowledge gaps and inform future management recommendations in patients with H. pylori infection from North America.

Novel carbonic anhydrase inhibitors for the treatment of Helicobacter pylori infection

INTRODUCTION

Helicobacter pylori, the causative agent of peptic ulcer, gastritis, and gastric cancer encodes two carbonic anhydrases (CA, EC 4.2.1.1) belonging to the α- and β-class (HpCAα/β), which have been validated as antibacterial drug targets. Acetazolamide and ethoxzolamide were also clinically used for the management of peptic ulcer.

AREAS COVERED

Sulfonamides were the most investigated HpCAα/β compounds, with several low nanomolar inhibitors identified, some of which also crystallized as adducts with HpCAα, allowing for the rationalization of the structure-activity relationship. Few data are available for other classes of inhibitors, such as phenols, sulfamides, sulfamates, dithiocarbamates, arylboronic acids, some of which showed effective in vitro inhibition and for phenols, also inhibition of planktonic growth, biofilm formation, and outer membrane vesicles spawning.

EXPERT OPINION

Several recent drug design studies reported selenazoles incorporating seleno/telluro-ethers attached to benzenesulfonamides, hybrids incorporating the EGFR inhibitor erlotinib and benzenesulfonamides, showing KIs < 100 nM against HpCAα and MICs in the range of 8-16 µg/mL for the most active derivatives. Few drug design studies for non-sulfonamide inhibitors were performed to date, although inhibition of these enzymes may help the fight of multidrug resistance to classical antibiotics which emerged in the last decades also for this bacterium.

Treatment of Helicobacter pylori with potassium competitive acid blockers: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infects over half the global population, causing gastrointestinal diseases like dyspepsia, gastritis, duodenitis, peptic ulcers, G-MALT lymphoma, and gastric adenocarcinoma. Eradicating H. pylori is crucial for treating and preventing these conditions. While conventional proton pump inhibitor (PPI)-based triple therapy is effective, there's growing interest in longer acid suppression therapies. Potassium competitive acid blocker (P-CAB) triple and dual therapy are new regimens for H. pylori eradication. Initially used in Asian populations, vonoprazan (VPZ) has been recently Food and Drug Administration-approved for H. pylori eradication.

AIM

To assess the efficacy of regimens containing P-CABs in eradicating H. pylori infection.

METHODS

This study, following PRISMA 2020 guidelines, conducted a systematic review and meta-analysis by searching MEDLINE and Scopus libraries for randomized clinical trials (RCTs) or observational studies with the following command: [("Helicobacter pylori" OR "H pylori") AND ("Treatment" OR "Therapy" OR "Eradication") AND ("Vonaprazan" OR "Potassium-Competitive Acid Blocker" OR "P-CAB" OR "PCAB" OR "Revaprazan" OR "Linaprazan" OR "Soraprazan" OR "Tegoprazan")]. Studies comparing the efficacy of P-CABs-based treatment to classical PPIs in eradicating H. pylori were included. Exclusion criteria included case reports, case series, unpublished trials, or conference abstracts. Data variables encompassed age, diagnosis method, sample sizes, study duration, intervention and control, and H. pylori eradication method were gathered by two independent reviewers. Meta-analysis was performed in R software, and forest plots were generated.

RESULTS

A total of 256 references were initially retrieved through the search command. Ultimately, fifteen studies (7 RCTs, 7 retrospective observational studies, and 1 comparative unique study) were included, comparing P-CAB triple therapy to PPI triple therapy. The intention-to-treat analysis involved 8049 patients, with 4471 in the P-CAB intervention group and 3578 in the PPI control group across these studies. The analysis revealed a significant difference in H. pylori eradication between VPZ triple therapy and PPI triple therapy in both RCTs and observational studies [risk ratio (RR) = 1.17, 95% confidence interval (CI): 1.11-1.22, P < 0.0001] and (RR = 1.13, 95%CI: 1.09-1.17, P < 0.0001], respectively. However, no significant difference was found between tegoprazan (TPZ) triple therapy and PPI triple therapy in both RCTs and observational studies (RR = 1.04, 95%CI: 0.93-1.16, P = 0.5) and (RR = 1.03, 95%CI: 0.97-1.10, P = 0.3), respectively.

CONCLUSION

VPZ-based triple therapy outperformed conventional PPI-based triple therapy in eradicating H. pylori, positioning it as a highly effective first-line regimen. Additionally, TPZ-based triple therapy was non-inferior to classical PPI triple therapy.

Molecular characterization of rifabutin-resistance in refractory Helicobacter pylori infection in Taiwan

OBJECTIVES

To explore the molecular characteristics of rpoB, encoding β-subunit of DNA-directed RNA polymerase, and unravel the link to rifabutin-resistance in patients with refractory Helicobacter pylori infection.

METHODS

From January 2018-March 2021, a total of 1590 patients were screened for eligibility to participate in the study. Patients with refractory H. pylori infection were confirmed by using the (13C)-urea breath assay. All enrolled patients underwent esophagogastroduodenoscopy, and biopsies were taken for H. pylori culture and antibacterial susceptibility testing. Sequence analysis of rpoB was conducted for all rifabutin-resistant isolates.

RESULTS

In total, 70 patients were diagnosed with refractory H. pylori infection, and 39 isolates were successfully cultured. Amongst, 10 isolates were identified as rifabutin-resistance and nine isolates exhibited at least one amino acid substitution in RpoB. Isolates with a minimal inhibitory concentration >32 mg/l displayed a higher number of mutational changes in RpoB than the others. Additionally, more amino acid substitutions in RpoB correlated with developing a higher minimal inhibitory concentration for H. pylori rifabutin-resistance.

CONCLUSION

Our findings highlight the relationship between rifabutin-resistance in refractory H. pylori infection and specific mutations in RpoB, which will aid the clinical selection of appropriate antibacterial agents with better therapeutic effects.

The Role of Helicobacter pylori and Small Intestinal Bacterial Overgrowth in Parkinson's Disease

Parkinson's disease (PD) is a common neurodegenerative disorder whose etiology remains largely unexplained. Several studies have aimed to describe a causative effect in the interactions between the gastrointestinal tract and the brain, for both PD pathogenesis and disease course. However, the results have been controversial. Helicobacter pylori and small intestinal bacterial overgrowth (SIBO) are theorized to be agents capable of triggering chronic proinflammatory changes with a possible neurotoxic effect, as well as a cause of erratic L-dopa response in PD patients. This review evaluates the individual and possibly synergistic influence of H. pylori and SIBO on PD, to provide an opportunity to consider prospective therapeutic approaches.