Macrolide use in the previous years is associated with failure to eradicate Helicobacter pylori with clarithromycin-containing regimens

The second Irish Helicobacter pylori Working Group consensus for the diagnosis and treatment of Helicobacter pylori infection in adult patients in Ireland

BACKGROUND

There has been an increase in resistance to many of the antimicrobials used to treat Helicobacter pylori ( H. pylori ) nationally and internationally. Primary clarithromycin resistance and dual clarithromycin and metronidazole resistance are high in Ireland. These trends call for an evaluation of best-practice management strategies.

OBJECTIVE

The objective of this study was to revise the recommendations for the management of H. pylori infection in adult patients in the Irish healthcare setting.

METHODS

The Irish H. pylori working group (IHPWG) was established in 2016 and reconvened in 2023 to evaluate the most up-to-date literature on H. pylori diagnosis, eradication rates and antimicrobial resistance. The 'GRADE' approach was then used to rate the quality of available evidence and grade the resulting recommendations.

RESULTS

The Irish H. pylori working group agreed on 14 consensus statements. Key recommendations include (1) routine antimicrobial susceptibility testing to guide therapy is no longer recommended other than for clarithromycin susceptibility testing for first-line treatment (statements 6 and 9), (2) clarithromycin triple therapy should only be prescribed as first-line therapy in cases where clarithromycin susceptibility has been confirmed (statement 9), (3) bismuth quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) is the recommended first-line therapy if clarithromycin resistance is unknown or confirmed (statement 10), (4) bismuth quadruple therapy with a proton pump inhibitor, levofloxacin and amoxicillin is the recommended second-line treatment (statement 11) and (5) rifabutin amoxicillin triple therapy is the recommend rescue therapy (statement 12).

CONCLUSION

These recommendations are intended to provide the most relevant current best-practice guidelines for the management of H. pylori infection in adults in Ireland.

Abundance and prevalence of ESBL coding genes in patients undergoing first line eradication therapy for Helicobacter pylori

The spread of extended-spectrum beta-lactamases (ESBLs) in nosocomial and community-acquired enterobacteria is an important challenge for clinicians due to the limited therapeutic options for infections that are caused by these organisms. Here, we developed a panel of ESBL coding genes, evaluated the abundance and prevalence of ESBL encoding genes in patients undergoing H. pylori eradication therapy, and summarized the effects of eradication therapy on functional profiles of the gut microbiome. To assess the repertoire of known beta lactamase (BL) genes, they were divided into clusters according to their evolutionary relation. Primers were designed for amplification of cluster marker regions, and the efficiency of this amplification panel was assessed in 120 fecal samples acquired from 60 patients undergoing H. pylori eradication therapy. In addition, fecal samples from an additional 30 patients were used to validate the detection efficiency of the developed ESBL panel. The presence for majority of targeted clusters was confirmed by NGS of amplification products. Metagenomic sequencing revealed that the abundance of ESBL genes within the pool of microorganisms was very low. The global relative abundances of the ESBL-coding gene clusters did not differ significantly among treatment states. However, at the level of each cluster, classical ESBL producers such as Klebsiella sp. for blaOXY (p = 0.0076), Acinetobacter sp. for blaADC (p = 0.02297) and others, differed significantly with a tendency to decrease compared to the pre- and post-eradication states. Only 13 clusters were common across all three datasets, suggesting a patient-specific distribution profile of ESBL-coding genes. The number of AMR genes detected in the post-eradication state was higher than that in the pre-eradication state, which could be attributed, at least in part, to the therapy. This study demonstrated that the ESBL screening panel was effective in targeting ESBL-coding gene clusters from bacterial DNA and that minor differences exist in the abundance and prevalence of ESBL-coding gene levels before and after eradication therapy.

Antibiotic Resistance, Susceptibility Testing and Stewardship in Helicobacter pylori Infection

Despite the declining trend of Helicobacter pylori (H. pylori) prevalence around the globe, ongoing efforts are still needed to optimize current and future regimens in view of the increasing antibiotic resistance. The resistance of H. pylori to different antibiotics is caused by different molecular mechanisms, and advancements in sequencing technology have come a far way in broadening our understanding and in facilitating the testing of antibiotic susceptibility to H. pylori. In this literature review, we give an overview of the molecular mechanisms behind resistance, as well as discuss and compare different antibiotic susceptibility tests based on the latest research. We also discuss the principles of antibiotic stewardship and compare the performance of empirical therapies based on up-to-date resistance patterns and susceptibility-guided therapies in providing effective H. pylori treatment. Studies and clinical guidelines should ensure that the treatment being tested or recommended can reliably achieve a pre-agreed acceptable level of eradication rate and take into account the variations in antibiotic resistance across populations. Local, regional and international organizations must work together to establish routine antibiotic susceptibility surveillance programs and enforce antibiotic stewardship in the treatment of H. pylori, so that it can be managed in a sustainable and efficient manner.

Exploration of the molecular mechanisms underlying the antibiotic resistance of Helicobacter pylori: A whole-genome sequencing-based study in Southern China

BACKGROUND

Although antimicrobial resistance (AMR) in Helicobacter pylori is a global threat to human health and the underlying molecular mechanisms have been explored previously, only a few of them are fully elucidated.

MATERIALS AND METHODS

In the present study, we isolated 54 Helicobacter pylori strains from Southern China and assessed their susceptibility to five antibiotics using the agar dilution assay. Whole-genome sequencing was performed to screen the AMR genotypes of the Helicobacter pylori isolates.

RESULTS

Our study revealed a high prevalence of resistance to clarithromycin (CLR), levofloxacin (LVX), and metronidazole (MTZ) in the Chinese isolates, 55.56% of which showed multidrug-resistant phenotypes. We screened for the 94 types of previously reported AMR mutations in 12 genes, but only a few of them were related to the AMR phenotype. Furthermore, we discovered four new mutations in the 23S rRNA gene and one mutation in infB related to CLR resistance. Another three mutations in gyrA and one in gyrB were closely correlated with the AMR pattern against LVX. We also demonstrated that the mutations R16C/H in rdxA, V56I in rpsU, and D54A in sodB might contribute to resistance to MTZ, which were previously reported in laboratory experiments but not found in clinical strains. We examined the concordance between the genotype and phenotype of AMR and identified several potential molecular biomarkers for predicting CLR and LVX resistance.

CONCLUSIONS

Our study explored the molecular mechanisms underlying the antibiotic resistance of Helicobacter pylori isolates from Southern China. We propose further epidemiologic investigations in China.

Clinical Factors Implicated in Antibiotic Resistance in Helicobacter pylori Patients

Helicobacter pylori is a common gastric pathogen associated with multiple clinical syndromes, including cancer. Eradication rates of H. pylori remain suboptimal despite the progress made in the past few decades in improving treatment strategies. The low eradication rates are mainly driven by antibiotic resistance of H. pylori. Non-invasive molecular testing to identify patients with antibiotic-resistant H. pylori represents a promising therapeutic avenue, however this technology currently remains limited by availability, costs, and lack of robust validation. Moreover, there is insufficient evidence to demonstrate that resistance-testing-based treatment approaches are superior to appropriately designed empiric strategies. Consensus guidelines recommend use of proven locally effective regimens; however, eradication data are inconsistently generated in several regions of the world. In this review, we describe several clinical factors associated with increased rates of antibiotic resistant H. pylori, including history of previous antibiotic exposure, increasing age, female gender, ethnicity/race, extent of alcohol use, and non-ulcer dyspepsia. Assessment of these factors may aid the clinician in choosing the most appropriate empiric treatment strategy for each patient. Future study should aim to identify locally effective therapies and further explore the clinical factors associated with antibiotic resistance.

Helicobacter pylori diagnosis and therapy in the era of antimicrobial stewardship

The diagnosis and therapy of Helicobacter pylori infection have undergone major changes based on the use the principles of antimicrobial stewardship and increased availability of susceptibility profiling. H. pylori gastritis now recognized as an infectious disease, as such there is no placebo response allowing outcome to be assessed in relation to the theoretically obtainable cure rate of 100%. The recent recognition of H. pylori as an infectious disease has changed the focus to therapies optimized to reliably achieve high cure rates. Increasing antimicrobial resistance has also led to restriction of clarithromycin, levofloxacin, or metronidazole to susceptibility-based therapies. Covid-19 resulted in the almost universal availability of polymerase chain reaction testing in hospitals which can be repurposed to utilize readily available kits to provide rapid and inexpensive detection of clarithromycin resistance. In the United States, major diagnostic laboratories now offer H. pylori culture and susceptibility testing and American Molecular Laboratories offers next-generation sequencing susceptibility profiling of gastric biopsies or stools for the six commonly used antibiotics without need for endoscopy. Current treatment recommendations include (a) only use therapies that are reliably highly effective locally, (b) always perform a test-of-cure, and (c) use that data to confirm local effectiveness and share the results to inform the community regarding which therapies are effective and which are not. Empiric therapy should be restricted to those proven highly effective locally. The most common choices are 14-day bismuth quadruple therapy and rifabutin triple therapy. Prior guidelines and treatment recommendations should only be used if proven locally highly effective.

Timing of prior exposure to antibiotics and failure of Helicobacter pylori eradication: a population-based study

BACKGROUND

The success rate of conventional Helicobacter pylori eradication therapy is declining, due to rising antibiotic resistance.

OBJECTIVES

To determine the temporal effects of prior antibiotic exposure on eradication outcome.

PATIENTS AND METHODS

This is a retrospective cohort study including all H. pylori-infected patients who received their first course of clarithromycin-containing triple therapy in 2003-18. Prior antibiotic exposures before H. pylori eradication therapy (up to 180 days, 1 year or 3 years) were retrieved. A logistic regression model was used to evaluate the association between different timings of previous antibiotic exposure, recent (within 30/60 days) or distant period, and the need for retreatment for H. pylori.

RESULTS

A total of 120 787 H. pylori-infected patients were included. Prior exposure to any antibiotics within 180 days was associated with a higher risk of retreatment (OR 1.18, 95% CI 1.13-1.24) and the risk progressively increased with longer duration of antibiotic use. The results were consistent for prior exposure up to 1 year (OR 1.26, 95% CI 1.20-1.31) or 3 years (OR 1.30, 95% CI 1.25-1.35). However, when compared with those without prior antibiotic exposure, recent exposure (within 30 days) did not increase the risk of retreatment, which was consistent for analysis with prior antibiotic exposure up to 3 years. Notably, recent use of cephalosporins within 30/60 days and nitroimidazole within 30 days had significantly lower risks of retreatment.

CONCLUSIONS

Any prior antibiotic exposure increased the risk of treatment failure of clarithromycin-containing triple therapy. Recent exposures to some classes of antibiotics may paradoxically increase treatment success.

Tailored eradication strategy vs concomitant therapy for Helicobacter pylori eradication treatment in Korean patients

BACKGROUND

Antibiotic resistance to Helicobacter pylori (H. pylori) infection, which ultimately results in eradication failure, has been an emerging issue in the clinical field. Recently, to overcome this problem, an antibiotic sensitivity-based tailored therapy (TT) for H. pylori infection has received attention.

AIM

To investigate the efficacy and safety profiles of TT for H. pylori infection treatment compared to a non-bismuth quadruple therapy, concomitant therapy (CT) regimen.

METHODS

We included patients (> 18 years) with an H. pylori infection and without a history of Helicobacter eradication who visited the Gil Medical Center between March 2016 and October 2020. After being randomly assigned to either the TT or CT treatment group in 1 to 1 manner, patient compliance, eradication success rate (ESR), and patient-reported side effects profiles were assessed and compared between the two groups. H. pylori infection was diagnosed using a rapid urease test, Giemsa stain, or dual priming oligonucleotide polymerase chain reaction (DPO-PCR). Tailored eradication strategy based through the presence of a 23S ribosomal RNA point mutation. For the TT group, a DPO-PCR test, which detected A2142G and/or A2143G point mutations, and a clarithromycin resistance test were performed. Patients in the clarithromycin-resistant group were treated with a bismuth-containing quadruple combination therapy, while those with sensitive results were treated with the standard triple regimen.

RESULTS

Of the 217 patients with a treatment naive H. pylori infection, 110 patients [mean age: 58.66 ± 13.03, men, n = 55 (50%)] were treated with TT, and 107 patients [mean age: 56.67 ± 10.88, men, n = 52 (48.60%)] were treated with CT. The compliance (TT vs CT, 100% vs 98.13%, P = 0.30), and follow-up loss rates (8.18% vs 9.35%, P = 0.95) were not significantly different between the groups. The ESR after treatment was also not statistically different between the groups (TT vs CT, 82.73% vs 82.24%, P = 0.95). However, the treatment-related and patient-reported side effects were significantly lower in the TT group than in the CT group (22.77% vs 50.52%, P < 0.001).

CONCLUSION

The DPO-based TT regimen shows promising results in efficacy and safety profiles as a first-line Helicobacter eradication regimen in Korea, especially when physicians are confronted with increased antibiotic resistance rates.

Efficacy of bismuth-based quadruple therapy for eradication of Helicobacter pylori infection based on previous antibiotic exposure: A large-scale prospective, single-center clinical trial in China

OBJECTIVE

This study aims to evaluate the efficacy and safety of three bismuth-based quadruple regimens for eradication of Helicobacter pylori (H pylori) infection in a large number of H pylori-positive patients with or without previous eradication therapy.

METHODS

Consecutive adult patients with H pylori infection, regardless of previous eradication therapy, were eligible for the present study. Three bismuth-based quadruple regimens were selected according to the past history of antibiotics use: (A) esomeprazole, amoxicillin, clarithromycin, and colloidal bismuth tartrate; (B) esomeprazole, amoxicillin, furazolidone, and colloidal bismuth tartrate; and (C) esomeprazole, doxycycline, furazolidone, and colloidal bismuth tartrate. All patients received a 14-day course of treatment, and ¹³ C/¹⁴ C urea breath test was utilized at four weeks after the completion of treatment to determine the H pylori eradication. Then, the eradication rates were calculated in terms of intention-to-treat (ITT) and per-protocol (PP) analyses. Adverse events (AEs) were recorded during the treatment.

RESULTS

Overall, 1,226 patients were recruited, and 331, 57, and 838 patients were allocated to receive regimens A, B, and C, respectively. The H pylori eradication rates were 84.0%, 82.5%, and 82.9% (ITT) and 94.6%, 92.2%, and 93.7% (PP), respectively, in regimens A, B, and C. However, there was no significant difference among these three regimens. The incidence of AEs was 4.6% for all patients during the study, that is, 3.3%, 10.5%, and 4.7% for regimens A, B, and C, respectively. All AEs were mild and recovered at the follow-up visit.

CONCLUSION

All three bismuth-based quadruple regimens based on the previous antibiotic use can achieve satisfactory eradication rates for H pylori infection and are safe.

Seven-day vonoprazan and low-dose amoxicillin dual therapy as first-line Helicobacter pylori treatment: a multicentre randomised trial in Japan

OBJECTIVE

To date, no randomised trials have compared the efficacy of vonoprazan and amoxicillin dual therapy with other standard regimens for Helicobacter pylori treatment. This study aimed to investigate the efficacy of the 7-day vonoprazan and low-dose amoxicillin dual therapy as a first-line H. pylori treatment, and compared this with vonoprazan-based triple therapy.

DESIGN

This prospective, randomised clinical trial was performed at seven Japanese institutions. Patients with H. pylori-positive culture test and naive to treatment were randomly assigned in a 1:1 ratio to either VA-dual therapy (vonoprazan 20 mg+amoxicillin 750 mg twice/day) or VAC-triple therapy (vonoprazan 20 mg+amoxicillin 750 mg+clarithromycin 200 mg twice/day) for 7 days, with stratification by age, sex, H. pylori antimicrobial resistance and institution. Eradication success was evaluated by ¹³C-urea breath test at least 4 weeks after treatment.

RESULTS

Between October 2018 and June 2019, 629 subjects were screened and 335 were randomised. The eradication rates of VA-dual and VAC-triple therapies were 84.5% and 89.2% (p=0.203) by intention-to-treat analysis, respectively, and 87.1% and 90.2% (p=0.372) by per-protocol analysis, respectively. VA-dual was non-inferior to VAC-triple in the per-protocol analysis. The eradication rates in strains resistant to clarithromycin for VA-dual were significantly higher than those for VAC-triple (92.3% vs 76.2%; p=0.048). The incidence of adverse events was equal between groups.

CONCLUSION

The 7-day vonoprazan and low-dose amoxicillin dual therapy provided acceptable H. pylori eradication rates and a similar effect to vonoprazan-based triple therapy in regions with high clarithromycin resistance.

TRIAL REGISTRATION NUMBER

UMIN000034140.

Treatment of Helicobacter pylori

PURPOSE OF REVIEW

Helicobacter pylori eradication has become more challenging over the past decade due to increasing antimicrobial resistance, especially to clarithromycin and levofloxacin. We identified 508 recent publications on H. pylori treatment (published between January 2018 and June 2019), focusing on the most highly clinically relevant for this review.

RECENT FINDINGS

Declining H. pylori eradication rates with clarithromycin triple therapy have led to most guidelines recommending 14 days bismuth-based quadruple therapy or concomitant therapy as the best initial empiric regimen. Substituting amoxicillin for tetracycline or metronidazole in quadruple therapy, and a three-in-one pill version of the regimen, also appear effective. Vonoprazan, a potent acid inhibitor, can overcome much clarithromycin resistance in triple therapy. High-dose dual therapy (proton pump inhibitor with amoxicillin) is a promising alternative approach. Reviewing resistance patterns to select suitable first-line empiric therapies is important in high resistance regions. Molecular methods to evaluate H. pylori antimicrobial susceptibility promise to be simpler than standard microbiological culture. The cost-effectiveness of antimicrobial susceptibility testing in refractory cases remains unproven.

SUMMARY

Updating clinicians treating H. pylori is important to combat the emerging problems of multidrug antimicrobial resistance in H. pylori strains. Truly novel approaches to H. pylori eradication are needed.

Impact of Previous Exposure to Macrolide Antibiotics on Helicobacter pylori Infection Treatment Outcomes

OBJECTIVES

Helicobacter pylori (H. pylori) guidelines, including the recent ACG clinical guideline, recommend avoiding clarithromycin-based triple therapy (TT-C) among patients with past macrolide exposure. Data to support this recommendation are scarce, and the impact of macrolide exposure on quadruple therapies is unclear. We aimed to determine the impact of macrolide exposure on the efficacy of H. pylori treatment in our region.

METHODS

We searched the Clalit Health Services database to identify subjects aged 25-60 years who underwent the first-ever C-urea breath test between 2010 and 2015. Patients who underwent a previous H. pylori stool antigen test or gastroscopy were excluded. Pharmacy dispensation data were retrieved.

RESULTS

We identified 7,842 subjects (36.1% male individuals, age: 40.3 ± 10.5 years), including 3,062 (39.0%) with previous macrolide exposure. The efficacy of TT-C was 74.3% and 82.4% among subjects with and without macrolide exposure, respectively (odds ratio (OR), 0.62; 95% confidence interval (CI), 0.55-0.70; P < 0.0001). TT success was adversely affected by exposure to clarithromycin (55.5%; OR, 0.31; 95% CI, 0.24-0.39; P < 0.0001), roxythromycin (74.4%; OR, 0.65; 95% CI, 0.58-0.74; P < 0.0001), and erythromycin (73.9%; OR, 0.72; 95% CI, 0.57-0.89; P < 0.01) but not by exposure to azithromycin. A greater time elapsed because exposure to clarithromycin and roxythromycin was associated with higher eradication (OR, 1.007; 95% CI, 1.002-1.012; P < 0.01 and OR, 1.004; 95% CI, 1.002-1.006; P < 0.0001). A higher dose of clarithromycin and roxythromycin was associated with a lower likelihood of successful eradication (OR, 0.99988; 95% CI, 0.99982-0.99996; P < 0.01 and OR, 0.99981; 95% CI, 0.99971-0.99992; P < 0.001). The efficacies of sequential and concomitant therapies were 82.7% and 81.3%, respectively, and were not significantly affected by macrolide exposure.

CONCLUSIONS

TT-C is adversely affected by previous exposure to macrolide antibiotics. Sequential, concomitant, and bismuth-based treatment may be preferred in this setting.

Treatment of Helicobacter pylori infection in 2018

Treatment options for the eradication of Helicobacter pylori continue to evolve. There have been many guidelines for H. pylori treatment published, which may lead to some confusion. However, most are in agreement with the most recent iteration of the Maastricht treatment guidelines. Triple therapy is still the most frequently used treatment, especially in areas of low clarithromycin resistance. Its best results are achieved when taken for a minimum of 10 days and with high-dose acid suppression. Quadruple therapy is gaining in popularity particularly in areas with increasing resistance to standard triple therapy. Whether three antibiotics, or bismuth and two antibiotics are used, excellent eradication rates are achieved, albeit with increased side effects. Levofloxacin second-line therapy is widely used; however bismuth, when available, is an increasingly successful option. Sequential therapy is challenging in terms of compliance and is no longer recommended. This past year witnessed a notable increase in the number of studies based on antimicrobial susceptibility testing and tailored eradication therapy, reflecting the role of culture-guided treatment, which may well represent the future of H. pylori treatment and prevent the inappropriate use of antibiotics.

Helicobacter pylori drug resistance: therapy changes and challenges

Helicobacter pylori is a Gram-negative bacterium that causes chronic gastritis, dyspepsia, peptic ulcers, and gastric cancer. Over half the world's population is infected with H. pylori, with higher prevalence in developing countries. Areas covered: In this review, current guidelines on H. pylori therapy, such as the Toronto consensus statement, the Maastricht V/Florence consensus report, and the American College of Gastroenterology guidelines, are compared. Also, we analyzed reports of antimicrobial resistance of H. pylori published in PubMed in the last years to determine current antimicrobial resistance worldwide. Expert commentary: Although H. pylori antimicrobial resistance varies by geographic area, its prevalence has been increasing over time, causing therapy failures and low eradication rates. To best optimize the management of H. pylori infection, H. pylori therapy should be based on patterns of local and individual antimicrobial resistance, if possible.