Antibiotic resistance and gyrA mutation affect the efficacy of 10-day sitafloxacin-metronidazole-esomeprazole therapy for Helicobacter pylori in penicillin allergic patients

Should Metronidazole Be Included in Second-Line Treatment After Standard Triple Therapy for Helicobacter pylori?: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIM

Although standard triple therapy remains the first-line eradication treatment for H. pylori worldwide, it is unclear whether metronidazole should be included empirically in second-line eradication treatments. The aim of this study was to compare the efficacy of metronidazole-containing regimens with that of metronidazole-free regimens after failure of first-line eradication using standard triple therapy.

METHODS

PubMed, the Cochrane Library, and the Igaku-Chuo-Zasshi database were searched to identify RCTs eligible for inclusion in this systematic review and meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Thirteen eligible RCTs were included, with a total of 2039 patients assigned to metronidazole-containing (975 patients) or metronidazole-free (1064 patients) regimens. Metronidazole-containing regimens had significantly lower eradication failure rates than regimens without metronidazole (OR 0.55; 95% CI, 0.39-0.78). Subgroup analysis based on the regional risk of metronidazole resistance demonstrated that metronidazole-containing regimens had lower eradication failure rates not only in low-risk regions but also in high-risk regions (OR, 0.29; 95% CI, 0.11-0.74 and OR, 0.66; 95% CI, 0.49-0.91, respectively).

CONCLUSION

After failure of standard triple therapy, secondary eradication treatment regimens containing metronidazole demonstrate higher eradication rates than those without metronidazole.

Cutting-edge insights into Helicobacter research

Non-Helicobacter pylori Helicobacter (NHPH) species are emerging as significant gastric pathogens. Despite their clinical importance, NHPH infections are less studied compared to Helicobacter pylori (H. pylori) due to their lower prevalence and diagnostic challenges. Zoonotic transmission, particularly from pigs, dogs, and cats, underscores the need for improved diagnostic methods and heightened clinical awareness. Gastric cancer (GC) remains a major global health issue, with H. pylori being a primary risk factor. The eradication of H. pylori reduces GC risk, but post-eradication surveillance is essential. Endoscopic findings, especially those from the Kyoto classification, and noninvasive biomarkers play crucial roles in early GC detection and risk assessment. The increasing antibiotic resistance in H. pylori necessitates new treatment strategies. Novel therapies, such as vonoprazan-based regimens, and alternatives like sitafloxacin and rifabutin, are being developed to improve eradication success rates. Understanding the fundamental mechanisms of gastric carcinogenesis, including the roles of oxidative stress and cancer stem cells, is key to advancing treatment. Targeting specific molecular pathways offers potential for more effective therapies.

Safety profile of Helicobacter pylori eradication treatments: literature review and updated data of the European Registry on Helicobacter pylori management (Hp-EuReg)

INTRODUCTION

Helicobacter pylori (H. pylori), the most prevalent chronic infection globally, is the major cause of relevant diseases such as gastric cancer, leading to high morbidity and mortality worldwide. Several studies have focused on optimize H. pylori eradication treatment through combination therapies and antibiotic resistance. However, the adverse events profile and its impact, as a primary outcome, remains underexplored.The aim of this review was to summarize the available data on the safety of the most common regimens for H. pylori eradication and its impact on the compliance.

AREAS COVERED

This review encompassed the published evidence from the years 2008 to 2023 regarding both the safety and compliance for most common H. pylori eradication regimens. The main sources for this review comprised MEDLINE, PubMed, and Cochrane electronic databases. Furthermore, it included a safety analysis of unpublished data from the European Registry on H. pylori management (Hp-EuReg).

EXPERT OPINION

Poor compliance is correlated with significantly lower cure rates, and this is a unique modifiable source of H. pylori treatment failure. Eradication treatments have become complex, involving multiple drugs and dosing intervals. Thus, patient education is crucial; doctors must explain to the patient about potential temporary and most often harmless side effects.

Treatment of Helicobacter pylori Infection in Patients with Penicillin Allergy

Helicobacter pylori is among the prevalent causes of infections worldwide, and its resistance rate to antibiotics has been rising over time. Amoxicillin is the cornerstone for the treatment regimen. However, the prevalence of penicillin allergy ranges from 4% to 15%. In patients with true allergy, Vonoprazan-Clarithromycin-Metronidazole and bismuth quadruple therapy have demonstrated excellent eradication and high adherence rates. Vonoprazan-based therapy is administered less frequently and may be better tolerated than bismuth quadruple therapy. Therefore, vonoprazan-based therapy may be considered as a first-line therapy if accessible. Bismuth quadruple therapy can be used as the initial therapy when vonoprazan is unavailable. Levofloxacin or sitafloxacin-based regimens achieve a moderately high eradication rate. However, these are associated with potentially serious adverse effects and should only be used when other effective and safer regimens are unavailable. Cephalosporins such as cefuroxime have been used as an alternative to amoxicillin. Microbial susceptibility studies can guide the selection of appropriate antibiotics. PPI-Clarithromycin-Metronidazole fails to achieve a high eradication rate and should be used as a second-line therapy. PPI-Clarithromycin-Rifabutin should not be used because of low eradication rate and frequent adverse reactions. The choice of the most effective antibiotic regimen can enhance clinical outcomes in patients with H. pylori infection and penicillin allergy.

Development of plasma ghrelin level as a novel marker for gastric mucosal atrophy after Helicobacter pylori eradication

BACKGROUND AND AIM

The severity of atrophic gastritis is significantly associated with the risk of gastric cancer. Although the current gold standard for assessing the gastric cancer risk is esophagogastroduodenoscopy with a pathological examination, the development of less-invasive biomarkers is warranted for efficient risk stratification of gastric cancer. Serum pepsinogens (PGs) are biomarkers used to predict the extent of gastric mucosal atrophy; however, they are not an accurate reflection of gastric mucosal atrophy after Helicobacter pylori eradication. The present study was conducted to investigate the usefulness of plasma ghrelin levels as a marker for gastric mucosal atrophy, and as a risk stratification marker for gastric cancer, even after H. pylori eradication.

METHODS

Patients who received H. pylori eradication treatment were enrolled in the study. The severity of gastric mucosal atrophy was evaluated both endoscopically and histologically. Serum pepsinogen and plasma ghrelin levels were measured before and at 1, 12, 24, and 48 weeks after treatment. The study was approved by the Research Ethics Committee of the Keio University School of Medicine (no. 20140102; 8 July 2014).

RESULTS

Eighteen patients completed the study protocol. Total and acyl plasma ghrelin levels demonstrated no significant change from before treatment to 48 weeks after eradication; however, there was a significant difference between open-type and closed-type atrophic gastritis. The PG I/II ratio increased significantly from 48 weeks after H. pylori eradication. The severity of the histological intestinal metaplasia scores correlated inversely with plasma total ghrelin levels from before to 48 weeks after H. pylori eradication.

CONCLUSION

Plasma levels of ghrelin correlate well with the level of gastric mucosal atrophy, even after H. pylori eradication.KEY MESSAGESGhrelin plasma levels are associated with the progression of endoscopic atrophic gastritis, even at 48 weeks after H. pylori eradication.Ghrelin plasma levels are also associated with increased severity of histological intestinal metaplasia 48 weeks after H. pylori eradication.Pepsinogen I/II ratios increased immediately after H. pylori eradication and are inappropriate for assessing atrophic gastritis after H. pylori eradication.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

V Spanish Consensus Conference on Helicobacter pylori infection treatment

Helicobacter pylori infection is very common in the Spanish population and represents the main cause of chronic gastritis, peptic ulcer, and gastric cancer. The last iteration of Spanish consensus guidelines on H. pylori infection was conducted in 2016. Recent changes in therapeutic schemes along with increasing supporting evidence were key for developing the V Spanish Consensus Conference (May 2021). Fourteen experts performed a systematic review of the scientific evidence and developed a series of recommendations that were subjected to an anonymous Delphi process of iterative voting. Scientific evidence and the strength of the recommendation were classified using GRADE guidelines. An eradication therapy, when prescribed empirically, is considered acceptable when it reliably achieves, or preferably surpass, 90% cure rates. Currently, only quadruple therapies (with or without bismuth) and generally lasting 14 days, accomplish this goal in first- and second-line therapies. A non-bismuth quadruple concomitant regimen (proton pump inhibitor, clarithromycin, amoxicillin, and metronidazole) or a quadruple bismuth-based combination (proton pump inhibitor, bismuth, tetracycline, and metronidazole), are recommended as first-line regimens. Rescue therapies after eradication failure and management of H. pylori infection in peptic ulcer disease were also reviewed.

Treatment of Helicobacter pylori infection in the presence of penicillin allergy

Therapy of Helicobacter pylori (H.pylori) requires a combination of antibiotics together with an acid suppressing agent; most treatment regimens include Amoxicillin as one of the antibiotics, which is an important constituent as resistance to it is low. However, allergies to the penicillin group of antibiotics are not uncommon, and treating H.pylori infection in such individuals can be challenging due to the restricted choice of regimens. The aim of this review is to summarise the evidence for therapeutic options in patients with H.pylori infection and penicillin allergy. A literature search was conducted in PubMed for English language publications using the key words ‘Helicobacter’ and ‘treatment’ or ‘therapy‘ and ‘penicillin’ or ‘beta-lactam’ and ‘allergy’ or ‘anaphylaxis’. Eighteen studies were identified that specifically evaluated H.pylori treatment success in penicillin allergic patients. The number of subjects in most of them was low and many were retrospective, uncontrolled, single cohort studies. The most effective option for first-line treatment appears to be Bismuth-based quadruple therapy for 10-14 d. The evidence supports second-line treatment with Levoflaxacin-based triple therapy for 10 d. Patients with persistent H.pylori infection after 2 treatment courses should be considered for testing to confirm penicillin allergy. Further treatment should be guided by the results of H.pylori culture and sensitivity testing.

Therapeutic Potential of Sitafloxacin as a New Drug Candidate for Helicobacter Eradication in Korea: An In Vitro Culture-Based Study

Background: Increased prevalence of antibiotic resistance to Helicobacter pylori (H. pylori) infection worldwide has driven the search for a new therapeutic candidate. Recently, sitafloxacin, a novel 4-quinolone agent, has emerged as a new therapeutic option for H. pylori eradication, in Japan. However, data on its efficacy for H. pylori eradication in Korea are limited. Therefore, we aimed to investigate the therapeutic potential of sitafloxacin as a first-line treatment for patients with Helicobacter infection through gastric tissue culture-based studies. Materials and Methods: We prospectively enrolled treatment-naïve patients with H. pylori infection who visited the Gil Medical Center between March 2015 and March 2018. After obtaining written informed consent from patients, a total of 121 H. pylori strains were collected. We tested the susceptibility of these strains to sitafloxacin, and other antibiotics for Helicobacter eradication, including clarithromycin (CLR), metronidazole (MTZ), amoxicillin (AMX), tetracycline (TET), levofloxacin (LEV), and ciprofloxacin (CIP) using the agar dilution technique. The minimum inhibitory concentration (MIC) of these antibiotics against H. pylori strains were determined. Results: None of the H. pylori strains obtained were resistant to sitafloxacin (MIC > 1, n = 0), while other conventional eradication drugs including CLR, MTZ, AMX, and TET showed 24.8% (n = 30), 30.6% (n = 37), 5.0% (n = 6), and 0.8% (n = 1) resistance, respectively. Compared to the resistance rates of other quinolones (LEV [36.4%, n = 44] and CIP [37.2%, n = 45]), sitafloxacin showed the best antibiotic performance against Helicobacter strains (0%, n = 0). Furthermore, sitafloxacin also inhibited the growth of 14 H. pylori strains (12.4%), which were resistant to both of clarithromycin, and metronidazole, and 27 strains (22.3%) with multidrug resistance. Conclusions: Sitafloxacin might be a new promising candidate for Helicobacter eradication where antibiotic resistance for Helicobacter is an emerging medical burden, such as in Korea.

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.

Sitafloxacin for Third-Line Helicobacter pylori Eradication: A Systematic Review

BACKGROUND AND AIM

Sitafloxacin-based therapy is a potent candidate for third-line Helicobacter pylori eradication treatment. In this systematic review, we summarise current reports with sitafloxacin-based therapy as a third-line treatment.

METHODS

Clinical studies were systematically searched using PubMed, Cochrane library, Web of Science, and the Igaku-Chuo-Zasshi database. We combined data from clinical studies using a random-effects model and calculated pooled event rates, 95% confidence intervals (CIs), and the pooled odds ratio (OR).

RESULTS

We included twelve clinical studies in the present systematic review. The mean eradication rate for 7-day regimens of either PPI (proton pump inhibitor) or vonoprazan-sitafloxacin-amoxicillin was 80.6% (95% CI, 75.2-85.0). The vonoprazan-sitafloxacin-amoxicillin regimen was significantly superior to the PPI-sitafloxacin-amoxicillin regimen (pooled OR of successful eradication: 6.00; 95% CI: 2.25-15.98, p < 0.001). The PPI-sitafloxacin-amoxicillin regimen was comparable with PPI-sitafloxacin-metronidazole regimens (pooled OR: 1.06; 95% CI: 0.55-2.07, p = 0.86).

CONCLUSIONS

Although the 7-day regimen composed of vonoprazan, sitafloxacin, and amoxicillin is a good option as the third-line Helicobacter pylori eradication treatment in Japan, the extension of treatment duration should be considered to further improve the eradication rate. Considering the safety concern of fluoroquinolones, sitafloxcin should be used after confirming drug susceptibility.

Optimization Strategies Aimed to Increase the Efficacy of Helicobacter pylori Eradication Therapies with Quinolones

H. pylori infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. Fluoroquinolones such as levofloxacin, or more recently moxifloxacin or sitafloxacin, are efficacious alternatives to standard antibiotics for H. pylori eradication. The aim of the present review is to summarize the role of quinolone-based eradication therapies, mainly focusing on the optimization strategies aimed to increase their efficacy. Several meta-analyses have shown that, after failure of a first-line eradication treatment, a levofloxacin-containing rescue regimen is at least equally effective, and better tolerated, than the generally recommended bismuth quadruple regimen. Compliance with the levofloxacin regimens is excellent, and the safety profile is favourable. Higher cure rates have been reported with longer treatments (>10-14 days), and 500 mg levofloxacin daily is the recommended dose. Adding bismuth to the standard triple regimen (PPI-amoxicillin-levofloxacin) has been associated with encouraging results. Unfortunately, resistance to quinolones is easily acquired and is increasing in most countries, being associated with a decrease in the eradication rate of H. pylori. In summary, a quinolone (mainly levofloxacin)-containing regimen is an encouraging second-line (or even third-line) strategy, and a safe and simple alternative to bismuth quadruple therapy in patients whose previous H. pylori eradication therapy has failed.

Helicobacter pylori first-line and rescue treatments in patients allergic to penicillin: Experience from the European Registry on H pylori management (Hp-EuReg)

BACKGROUND

Experience in Helicobacter pylori eradication treatment of patients allergic to penicillin is very scarce. A triple combination with a PPI, clarithromycin (C), and metronidazole (M) is often prescribed as the first option, although more recently the use of a quadruple therapy with PPI, bismuth (B), tetracycline (T), and M has been recommended.

AIM

To evaluate the efficacy and safety of first-line and rescue treatments in patients allergic to penicillin in the "European Registry of H pylori management" (Hp-EuReg).

METHODS

A systematic prospective registry of the clinical practice of European gastroenterologists (27 countries, 300 investigators) on the management of H pylori infection. An e-CRF was created on AEG-REDCap. Patients with penicillin allergy were analyzed until June 2019.

RESULTS

One-thousand eighty-four patients allergic to penicillin were analyzed. The most frequently prescribed first-line treatments were as follows: PPI + C + M (n = 285) and PPI + B + T + M (classic or Pylera® ; n = 250). In first line, the efficacy of PPI + C + M was 69%, while PPI + B + T + M reached 91% (P < .001). In second line, after the failure of PPI + C + M, two rescue options showed similar efficacy: PPI + B + T + M (78%) and PPI + C + levofloxacin (L) (71%) (P > .05). In third line, after the failure of PPI + C + M and PPI + C + L, PPI + B + T + M was successful in 75% of cases.

CONCLUSION

In patients allergic to penicillin, a triple combination with PPI + C + M should not be generally recommended as a first-line treatment, while a quadruple regimen with PPI + B + T + M seems to be a better option. As a rescue treatment, this quadruple regimen (if not previously prescribed) or a triple regimen with PPI + C + L could be used but achieved suboptimal (<80%) results.

Primary and secondary antibiotic resistance of Helicobacter pylori in Korea from 2003 to 2018

BACKGROUND

Antimicrobial resistance of Helicobacter pylori (H pylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of H pylori isolates to antibiotics in Korea.

METHODS

The present study was performed from 2003 to 2018. Primary resistance was evaluated in 591 patients without any history of eradication and secondary resistance in 149 patients from whom Helicobacter pylori was cultured after failure of eradication. A minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and rifabutin using the agar dilution method.

RESULTS

An increase in the primary resistance rate was found in clarithromycin (P < .001), metronidazole (P < .001), and both levofloxacin (P < .001) during the study period. The primary resistance rates of amoxicillin and tetracycline were low and stable during the study period. The secondary resistance rate significantly increased in metronidazole and levofloxacin (P = .022 and .039, respectively).

CONCLUSIONS

The primary and secondary resistance rates of clarithromycin, metronidazole, and levofloxacin for Helicobacter pylori in Korea were high and increased over time. However, the primary and secondary resistance rates of amoxicillin and tetracycline were low and stable over time. These results will help in selecting effective eradication regimens of H pylori in Korea in the future.

Effective therapeutic regimens in two South Asian countries with high resistance to major Helicobacter pylori antibiotics

Background

Nepal and Bangladesh have a high prevalence of Helicobacter pylori with high resistance rates to clarithromycin, metronidazole, and levofloxacin. Here, we evaluated the susceptibility and genetic mutations of 5 alternative antibiotics against isolates from both countries to obtain an effective treatment regimen for H. pylori eradication.

Methods

We used the agar dilution method to determine the minimal inhibitory concentration of 5 alternative antibiotics against 42 strains from Nepal and 56 from Bangladesh and performed whole genome mutation analysis.

Results

No resistance to furazolidone or rifabutin and a high susceptibility of sitafloxacin (95.2% in Nepal and 98.2% in Bangladesh) were observed. In contrast, resistance to rifaximin (52.4% in Nepal and 64.3% in Bangladesh) was high. Moreover, resistance to garenoxacin was higher in Bangladesh (51.6%) than in Nepal (28.6%, P = 0.041), most likely due to its correlation with levofloxacin resistance (P = 0.03). Garenoxacin and rifaximin were significantly correlated in Bangladesh (P = 0.014) and occurred together with all sitafloxacin-resistant strains. Mutations of gyrA could play a significant role in garenoxacin resistance, and double mutations of A87 and D91 were associated with sitafloxacin resistance. Analysis of the rpoB gene demonstrated well-known mutations, such as V657I, and several novel mutations, including I2619V, V2592 L, T2537A, and F2538 L.

Conclusions

Rifabutin can be cautiously implemented as therapy for H. pylori infection due to its interaction with the tuberculosis endemic in Bangladesh. The high susceptibility of furazolidone and sitafloxacin suggests their possible future application in Nepal and Bangladesh.

Acquisition of double mutation in gyrA caused high resistance to sitafloxacin in Helicobacter pylori after unsuccessful eradication with sitafloxacin-containing regimens

BACKGROUND AND AIM

Although sitafloxacin (STFX)-containing regimens are effective rescue treatments for Helicobacter pylori infection, prevalence of fluoroquinolone resistance in H. pylori has increased rapidly worldwide. The change in resistance levels and gyrA mutations, a major cause of fluoroquinolone resistance, after unsuccessful STFX-containing treatment has not been investigated.

METHODS

We conducted a retrospective, non-randomized study to compare the minimum inhibitory concentrations (MICs) of STFX and the location of gyrA mutations in H. pylori before and after unsuccessful eradication with STFX-containing regimens at Keio University Hospital between December 2011 and March 2015.

RESULTS

A total of 266 patients treated with STFX-containing regimens for third-line H. pylori eradication were evaluated. Double mutations in gyrA were acquired by 20.8% of strains that exhibited seven-fold increased STFX MICs, compared to pre-treatment MICs. The STFX MICs did not increase, however, when the location of the gyrA mutations did not change after treatment. Double mutations in gyrA developed in 60.0% of the strains in which eradication failed, which exhibited a baseline mutation at position D91, and in 11.1% of strains with baseline mutations at position N87.

CONCLUSION

Acquisition of double mutations in gyrA evoked high-level resistance to STFX in H. pylori after unsuccessful eradication with STFX-containing regimens.