Rifabutin based triple therapy for eradication of H. pylori primary and secondary resistant to tinidazole and clarithromycin

Rifabutin-Containing Triple Therapy Versus Bismuth Quadruple Therapy for Helicobacter pylori Rescue Treatment: A Multicenter, Randomized Controlled Trial

BACKGROUND

We compared the efficacy and safety of rifabutin-containing triple therapy with bismuth quadruple therapy for rescue treatment of Helicobacter pylori.

METHODS

This was a noninferiority study trial of H. pylori treatment for subjects who had failed at least 2 prior treatments. Subjects were randomly assigned to receive rifabutin triple therapy with 14-day esomeprazole (20 mg), amoxicillin (1.0 g), and rifabutin (150 mg) twice a day; or bismuth quadruple therapy with esomeprazole (20 mg) and bismuth (220 mg) twice a day, plus metronidazole (400 mg) and tetracycline (500 mg) 4 times a day. Antimicrobial susceptibility was assessed by agar dilution and E-test.

RESULTS

From May 2021 to October 2022, a total of 364 subjects were randomized. The eradication rates by intention-to-treat, per-protocol, and modified intention-to-treat were 89.0% (162/182; 95% confidence interval [CI], 83.6%-92.8%), 94.0% (157/167; 95% CI, 89.3%-96.7%), and 93.6% (162/173; 95% CI, 89.0%-96.4%) for rifabutin triple group. For bismuth quadruple group, they were 89.6% (163/182; 95% CI, 84.3%-93.2%), 95.3% (143/150; 95% CI, 90.7%-97.7%), and 93.7% (163/174; 95% CI, 89.0%-96.4%).

CONCLUSIONS

The rifabutin triple therapy is an alternative to classical bismuth quadruple therapy for the rescue treatment of H. pylori with fewer side effects and higher compliance.

CLINICAL TRIALS REGISTRATION

NCT04879992.

Experience with Rifabutin-Containing Therapy in 500 Patients from the European Registry on Helicobacter pylori Management (Hp-EuReg)

BACKGROUND

First-line Helicobacter pylori (H. pylori) treatments have been relatively well evaluated; however, it remains necessary to identify the most effective rescue treatments. Our aim was to assess the effectiveness and safety of H. pylori regimens containing rifabutin.

METHODS

International multicentre prospective non-interventional European Registry on H. pylori Management (Hp-EuReg). Patients treated with rifabutin were registered in AEG-REDCap e-CRF from 2013 to 2021. Modified intention-to-treat and per-protocol analyses were performed. Data were subject to quality control.

RESULTS

Overall, 500 patients included in the Hp-EuReg were treated with rifabutin (mean age 52 years, 72% female, 63% with dyspepsia, 4% with peptic ulcer). Culture was performed in 63% of cases: dual resistance (to both clarithromycin and metronidazole) was reported in 46% of the cases, and triple resistance (to clarithromycin, metronidazole, and levofloxacin) in 39%. In 87% of cases rifabutin was utilised as part of a triple therapy together with amoxicillin and a proton-pump-inhibitor, and in an additional 6% of the patients, bismuth was added to this triple regimen. Rifabutin was mainly used in second-line (32%), third-line (25%), and fourth-line (27%) regimens, achieving overall 78%, 80% and 66% effectiveness by modified intention-to-treat, respectively. Compliance with treatment was 89%. At least one adverse event was registered in 26% of the patients (most frequently nausea), and one serious adverse event (0.2%) was reported in one patient with leukopenia and thrombocytopenia with fever requiring hospitalisation.

CONCLUSION

Rifabutin-containing therapy represents an effective and safe strategy after one or even several failures of H. pylori eradication treatment.

Potential utility of nano-based treatment approaches to address the risk of Helicobacter pylori

INTRODUCTION

Helicobacter pylori (H. pylori) has occupied a significant place among infectious pathogens and it has been documented as a leading challenge due to its higher resistance to the commonly used drugs, higher adaptability, and lower targeting specificity of the available drugs.

AREAS COVERED

New treatment strategies are urgently needed in order to improve the current advancement in modern medicine. Nanocarriers have gained an advantage of drug encapsulation and high retention time in the stomach with a prolonged drug release rate at the targeted site. This article aims to highlight the recent advances in nanotechnology with special emphasis on metallic, polymeric, lipid, membrane coated, and target-specific nanoparticles (NPs), as well as, natural products for treating H. pylori infection. We discussed a comprehensive approach to understand H. pylori infection and elicits to rethink about the increasing threat posed by H. pylori and its treatment strategies.

EXPERT OPINION

To address these issues, nanotechnology has got huge potential to combat H. pylori infection and has made great progress in the field of biomedicine. Moreover, combinatory studies of natural products and probiotics in conjugation with NPs have proven efficiency against H. pylori infection, with an advantage of lower cytotoxicity, minimal side effects, and stronger antibacterial potential.[Figure: see text].

Evaluating treatments with rifabutin and amoxicillin for eradication of Helicobacter pylori infection in adults: a systematic review

INTRODUCTION

Helicobacter pylori causes dyspepsia, peptic ulcer, and gastric malignancies. Treatments for Helicobacter pylori are mostly empirical depending on regional antibiotic resistances and the patient's history and less frequently susceptibility guided. Helicobacter pylori has a low resistance to rifabutin and has been proposed as an alternative for third-line treatment and beyond but recently has also gained attention for use as first- and second-line treatment.

AREAS COVERED

In this review, the authors systematically searched medical databases in order to present the current eradication rates for any treatment based on the two antibiotics, rifabutin and amoxicillin with a potent acid inhibitor. They also assessed the safety and tolerance of all the relative regimens.

EXPERT OPINION

Treatment with a rifabutin- and amoxicillin-containing regimen is a valuable option when treating difficult to eradicate Helicobacter pylori infections. Its efficacy is overall 71.4%, and it is not influenced by previous antibiotics, gender, smoking habits, and age. Its results were better when used as a first- or second-line treatment. In third-line therapy and beyond, eradication rates are lower. Adverse effects of all rifabutin regimens occurred in 23% of patients and were mostly mild with bone marrow suppression being very low and reversible.

Rifabutin triple therapy for first-line and rescue treatment of Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND AND AIM

Due to the increasing resistance of Helicobacter pylori, there is a need for novel antibiotic treatment protocols. We aimed to perform a systematic review and meta-analysis in order to determine the effectiveness and safety of rifabutin triple therapy for H. pylori infection.

METHODS

We performed a systematic review of prospective clinical trials with a treatment arm consisting of proton pump inhibitor, amoxicillin, and rifabutin and a meta-analysis of randomized controlled trials (RCTs).

RESULTS

Thirty-three prospective studies including 44 datasets were identified. Meta-analysis of four RCTs for rescue treatment found no difference between treatment groups (odds ratio [OR] 0.88, 95% confidence interval [CI] 0.437-1.791, I²  = 68.1%, P = 0.733). Only one RCT compared rifabutin therapy with control for first-line treatment of H. pylori infection (OR 3.78, 95% CI 2.44-5.87, P < 0.0001). Treatment was more likely to be successful in Asian versus non-Asian populations (81.0% vs 72.4%, P = 0.001) and when daily amoxicillin dose was ≥ 3000 mg or proton pump inhibitor dose was ≥ 80 mg or treatment duration was 14 days (80.6% vs 66.0%, P = 0.0001). The overall event rate for adverse effects was 24.8% (729/2937) (95% CI 0.23-0.26), and the pooled OR for adverse effects in the treatment versus control group was 0.93 (95% CI 0.50-1.75) (I²  = 79.76, P = 0.82).

CONCLUSION

Evidence for the effectiveness of rifabutin for the first-line treatment of H. pylori infection in adults is limited, and studies comparing rifabutin with conventional first-line treatments are lacking.

Rescue Therapies for H. pylori Infection in Italy

Background/Aims: Curing Helicobacter pylori infection remains challenging for clinicians, as no proposed first-line therapy achieves bacterial eradication in all treated patients so that several patients need two or more consecutive treatments. Bacterial culture with antibiotics susceptibility testing is largely unachievable in Italy, and empiric second-line and rescue therapies are generally used. This study aimed to identify what eradication regimens perform better in Italy, following first-line therapy failure. Methods: We performed a literature search on PubMed for studies on standard therapy regimens used as second-line or rescue treatments performed in adult patients. Studies including modified drug combinations were not considered. Both intention-to-treat and per- protocol analyses were computed for each therapy subgroup. Results: Data from 35 studies with a total of 4830 patients were eventually considered. As a second-line therapy, Pylera® (90.6%) and a sequential regimen (89.8%) achieved eradication rates significantly higher than other therapies. For third-line therapy, a levofloxacin-based regimen and Pylera® achieved comparable eradication rates (88.2% vs. 84.7%; p = 0.2). Among therapies used as fourth (or more) attempts, Pylera® and a rifabutin-based therapy achieved 77.4% and 66.4% cure rates, respectively (p = 0.013). A therapy sequence based on the type of first-line therapy used was proposed. Conclusions: Data obtained through our review indicate that standard therapies for H. pylori eradication can be used when following an appropriate sequence, allowing clinicians to improve the cure rate without resorting to bacterial culture.

Rifabutin for the Treatment of Helicobacter Pylori Infection: A Review

Nowadays, apart from having to know first-line Helicobacter pylori eradication regimens well, we must also be prepared to face treatment failures. The aim of this review is to summarize the role of rifabutin in the management of H. pylori infection. Bibliographical searches were performed in PubMed. Data on resistance and efficacy of rifabutin-containing regimens on H. pylori eradication were meta-analyzed. Mean H. pylori rifabutin resistance rate (39 studies, including 9721 patients) was 0.13%; when studies only including patients naïve to H. pylori eradication treatment were considered, this figure was even lower (0.07%). Mean H. pylori eradication rate (by intention-to-treat) with rifabutin-containing regimens (3052 patients) was 73%. Respective cure rates for second-, third-, fourth- and fifth-line therapies, were 79%, 69%, 69% and 72%. Most studies administered rifabutin 300 mg/day, which seemed to be more effective than 150 mg/day. The ideal length of treatment remains unclear, but 10–12-day regimens are generally recommended. Adverse events to rifabutin treatment in H. pylori studies were relatively infrequent (15%), and severe adverse events were exceptional (myelotoxicity was the most significant, although always reversible). In summary, rifabutin-containing therapy represents an encouraging strategy generally restricted, at present, to patients where previous (usually multiple) eradication regimens have failed.

Resistance patterns of refractory H. pylori infection in a referral center in the Delaware Valley

Introduction

H. pylori (HP) resistance is increasing in the US. Guidelines suggest treatment based on local resistance patterns, yet are poorly studied. We describe resistance patterns of the Delaware Valley.

Methods

A retrospective study of patients referred to the Hospital of the University of Pennsylvania, between 2009-2019 who underwent endoscopy for culture. Chart review identified demographics, history, endoscopic and culture results, treatment, and follow up.

Results

Of 109 patients referred for refractory HP, 90 had identified HP. Median age was 53.2 years and the majority was female (74%), with median 2 previous antibiotic courses for HP. Gastric erythema was the most common endoscopic abnormality. 65 (72.2%) were culture positive, and 45 (69.2%) were resistant to levofloxacin, 27 (41.5%) to metronidazole, and 39 (43.3%) to clarithromycin.Being resistant to any one of the 3 antibiotics was associated with resistance to either of the other two. There was an association with number of previous antibiotics with resistance (OR 1.74, p<0.05).We prescribed therapy to 77 patients based on susceptibility profiles, and 34 (37.8%) were cured, 14 (15.6%) underwent endoscopic surveillance, 3 (3.3%) were followed by infectious disease, and 39 (43.3%) were lost to follow up.

Conclusions

Antibiotic resistance is associated with refractory HP, and continues to rise. Culturing is associated with cure, and its use in clinical practice regarding efficacy, cost-effectiveness, and ability to minimize antibiotic resistance should be further studied. Overall follow-up is limited by loss to follow up, emphasizing the need for appropriate treatment.

Treatment of Helicobacter pylori in Special Patient Populations

Helicobacter pylori infection can lead to gastritis, gastric and duodenal ulcers, and gastric cancer. Consequently, complete eradication is the goal of therapy. First-line therapy for H. pylori infection includes clarithromycin triple therapy (clarithromycin, proton pump inhibitor [PPI], and amoxicillin or metronidazole), bismuth quadruple therapy (bismuth salt, PPI, tetracycline, and metronidazole or amoxicillin), or concomitant therapy (clarithromycin, PPI, amoxicillin, and metronidazole). However, many patients have relative contraindications to the antibiotics included in these regimens, making therapy selection difficult. Furthermore, failure of initial therapy makes selection of second-line therapy challenging due to concerns for potential resistance to agents included in the initial regimen. This review discusses H. pylori microbiology, including antibiotic resistance, and summarizes the existing evidence for first- and second-line treatment regimens that may be considered for special populations such as patients with penicillin allergies, patients with or at risk for QTc-interval prolongation, and patients who are pregnant, breastfeeding, or elderly.

Review of current diagnostic methods and advances in Helicobacter pylori diagnostics in the era of next generation sequencing

Helicobacter pylori (H. pylori) infection is highly prevalent in the human population and may lead to severe gastrointestinal pathology including gastric and duodenal ulcers, mucosa associated tissue lymphoma and gastric adenocarcinoma. In recent years, an alarming increase in antimicrobial resistance and subsequently failing empiric H. pylori eradication therapies have been noted worldwide, also in many European countries. Therefore, rapid and accurate determination of H. pylori’s antibiotic susceptibility prior to the administration of eradication regimens becomes ever more important. Traditionally, detection of H. pylori and its antimicrobial resistance is done by culture and phenotypic drug susceptibility testing that are cumbersome with a long turn-around-time. Recent advances in diagnostics provide new tools, like real-time polymerase chain reaction (PCR) and line probe assays, to diagnose H. pylori infection and antimicrobial resistance to certain antibiotics, directly from clinical specimens. Moreover, high-throughput whole genome sequencing technologies allow the rapid analysis of the pathogen’s genome, thereby allowing identification of resistance mutations and associated antibiotic resistance. In the first part of this review, we will give an overview on currently available diagnostic methods for detection of H. pylori and its drug resistance and their implementation in H. pylori management. The second part of the review focusses on the use of next generation sequencing technology in H. pylori research. To this end, we conducted a literature search for original research articles in English using the terms “Helicobacter”, “transcriptomic”, “transcriptome”, “next generation sequencing” and “whole genome sequencing”. This review is aimed to bridge the gap between current diagnostic practice (histology, rapid urease test, H. pylori culture, PCR and line probe assays) and new sequencing technologies and their potential implementation in diagnostic laboratory settings in order to complement the currently recommended H. pylori management guidelines and subsequently improve public health.

Alternative eradication regimens for Helicobacter pylori infection in Indonesian regions with high metronidazole and levofloxacin resistance

Background

The prevalence of Helicobacter pylori resistance to metronidazole and clarithromycin is high in Indonesia. Moreover, the increasing levofloxacin resistance rates in the absence of bismuth treatment in Indonesia has led to the use of other antibiotics as alternative regimens.

Methods

We determined the minimum inhibitory concentrations (MICs) of five alternative antibiotics for H. pylori (rifaximin, rifabutin, furazolidone, garenoxacin, and sitafloxacin) using the agar dilution method and assessed mutations associated with antibiotic resistance using next-generation sequencing.

Result

Analysis of 106 strains isolated from 1039 adult dyspeptic patients revealed that none of the strains were furazolidone-resistant. All strains were also sensitive to rifabutin and sitafloxacin. In contrast, the rates of resistance to rifaximin and garenoxacin were high (38.9% and 6.7%, respectively). The strains isolated from patients on Java Island had the highest resistance rates to garenoxacin and rifaximin. In addition, the resistance was distributed evenly among the ethnic groups, ranging between 25.0% and 69.2%. Except for rifaximin, for which the resistance rate was 38.9%, the other four antibiotics could be successfully employed to eradicate levofloxacin- and metronidazole-resistant H. pylori infections in vitro. Interestingly, garenoxacin-sensitive strains were found in regions with high clarithromycin resistance rates such as Bali and Papua Islands. In contrast, rifaximin might not be considered as an alternative antibiotic in regions with high clarithromycin resistance. There was an inconsistent association between gyrA and gyrB mutations and garenoxacin resistance. We confirmed that the I837V (replacement of isoleucine at position 837 with valine), A2414T/V, Q2079K and K2068R were the predominant rpoB point mutations. There was an association between vacA genotypes of H. pylori and rifaximin resistance (P = 0.048).

Conclusion

furazolidone-, rifabutin-, and sitafloxacin-based therapies might be considered as alternative regimens to eradicate H. pylori in Indonesia, including regions with high metronidazole and clarithromycin resistance rates. Moreover, sitafloxacin but not garenoxacin should be considered for eradication of levofloxacin-resistant strains.

Molecular characterization of Helicobacter pylori resistance to rifamycins

INTRODUCTION

Antibiotic resistance is a major contributing factor in treatment failure of Helicobacter pylori eradication. Rifabutin (RB) is a rescue treatment and rifampicin (RP) is used to screen RB resistance in vitro. The aim of this study was to evaluate the rate of rifamycins resistance and to determine the mutations in the rpoB gene conferring resistance to discuss the current break point.

METHODS

Antimicrobial susceptibility to RP was first determined by E-test for 1015 H. pylori isolates. RP and RB MICs were then determined by agar dilution method for strains with MIC of RP > 1 mg/L, and the rpoB gene was sequenced.

RESULTS

Overall, 54 of 1015 strains exhibited a RP MIC > 1 mg/L by agar dilution method. Among these 54 strains, 10 had MICs of RP > 4 mg/L and RB ≥ 1 mg/L. They all carried at least one mutation in the rpoB gene at codons 530, 538, 540, 525 in the RP resistance-determining region (RRDR). Implication of the mutation L547F was confirmed by site-directed mutagenesis experiment. In contrast, among the 44 H. pylori isolates with a MIC of RP comprised between 2 and 4 mg/L, only 4 of 44 (9%) strains exhibited a mutation in rpoB, but outside RRDR (codons 470, 499, 636, or 657). For 31 of 44 tested strains, the RB MICs were ≤0.064 mg/L.

CONCLUSION

These results suggest that H. pylori isolates should be classified as resistant to RP for MICs > 4 mg/L. We considered that the optimal cut off for RB was ≥0.125 mg/L. We report a new mutation responsible for rifamycins, resistance, L547F.

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

BACKGROUND

Irish eradication rates for Helicobacter pylori are decreasing and there is an increase in the prevalence of antibiotic-resistant bacteria. These trends call into question current management strategies.

OBJECTIVE

To establish an Irish Helicobacter pylori Working Group (IHPWG) to assess, revise and tailor current available recommendations.

METHODS

Experts in the areas of gastroenterology and microbiology were invited to join the IHPWG. Questions of relevance to diagnosis, first-line and rescue therapy were developed using the PICO system. A literature search was performed. The 'Grading of Recommendations Assessment, Development and Evaluation' approach was then used to rate the quality of available evidence and grade the resulting recommendations.

RESULTS

Key resultant IHPWG statements (S), the strength of recommendation and quality of evidence include S8: standard triple therapy for 7 days' duration can no longer be recommended (strong and moderate). S9: 14 days of clarithromycin-based triple therapy with a high-dose proton pump inhibitor (PPI) is recommended as first-line therapy. Bismuth quadruple therapy for 14 days is an alternative if available (strong and moderate). S12: second-line therapy depends on the first-line treatment and should not be the same treatment. The options are (a) 14 days of levofloxacin-based therapy with high-dose PPI, (b) 14 days of clarithromycin-based triple therapy with high-dose PPI or (c) bismuth quadruple therapy for 14 days (strong and moderate). S13: culture and antimicrobial susceptibility testing should be performed following two treatment failures (weak and low/very low).

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.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to 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 the various clinical scenarios.

Rifabutin Containing Triple Therapy and Rifabutin with Bismuth Containing Quadruple Therapy for Third-Line Treatment of Helicobacter pylori Infection: Two Pilot Studies

AIM

To evaluate the therapeutic gain of the addition of bismuth to a rifabutin containing triple therapy with amoxicillin and pantoprazole at standard dosages for the treatment of third-line Helicobacter pylori infection after a preliminary susceptibility test.

METHODS

Two separate groups of patients in two pilot studies which were carried out simultaneously. One group was treated with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., and amoxicillin 1 g b.i.d. for 10 days and the other group with rifabutin 150 mg b.i.d., pantoprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and bismuth subcitrate 240 mg b.i.d. for 10 days. All patients underwent to culture and susceptibility testing prior to their inclusion in the study. A successful outcome was confirmed with an Urea Breath test performed 8 weeks after the end of treatment. A blood cell count was performed for all patients at the start and after 5 days of treatment since rifabutin has been shown to inhibit the growth of leucocytes.

RESULTS

Twenty-nine patients were recruited in the pantoprazole, amoxicillin, rifabutin group and 30 in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. All patients had a positive H. pylori culture and the susceptibility test used showed H. pylori sensitivity to rifabutin and amoxicillin. H. pylori eradication during follow-up was 18/27 (66.7%, 95% CI: 47.7-85.7%) in the pantoprazole, amoxicillin, rifabutin group and 28/29 (96.6%, 95% CI: 89.5-100.0%) in the pantoprazole, amoxicillin, rifabutin, and bismuth subcitrate group. Both treatments were well-tolerated with no reported side effects. Blood cell count remained normal in all patients.

CONCLUSION

The addition of bismuth subcitrate to a triple therapy that includes proton pump inhibitors, amoxicillin, and rifabutin in patients who are treated for the third time for H. pylori infection resulted in a 30% therapeutic gain.

Rescue Therapy with a Proton Pump Inhibitor Plus Amoxicillin and Rifabutin for Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background. To conduct a systematic review and meta-analysis of clinical trials for eradication of Helicobacter pylori (H. pylori) that included a treatment arm with a proton pump inhibitor, rifabutin, and amoxicillin. Materials and Methods. We selected clinical trials that examined the efficacy of H. pylori eradication therapies and included a study arm using the test regimen from major medical literature databases and abstracts from major gastroenterology meetings. We also did subgroup and sensitivity analyses. Results. Twenty-one studies were included in systematic review. The total eradication rates of the test regimen were 70.4% by intent-to-treat (ITT) and 72.0% by per-protocol (PP) analyses. The pooled odds ratio (OR) was 0.55 using fixed effects model (P = 0.283) for the test regimen versus other triple regimens. The total eradication rates were 68.4% for the test regimen and 81.9% in the control group by ITT, while the OR was 1.08 using random effects model (P = 0.019). The pooled eradication rate was 66.4% for the test regimen and 67.4% for the control group by ITT. The total adverse effects incidence were 25.1% for the test regimen. Conclusions. The test regimen for H. pylori rescue therapy may be not superior to control regimens in efficacy.

Rifabutin-based high-dose proton-pump inhibitor and amoxicillin triple regimen as the rescue treatment for Helicobacter pylori

BACKGROUND

Rifabutin has been known to be effective in multidrug-resistant Helicobacter pylori-harboring patients undergoing treatment failure for H. pylori infection.

AIM

To evaluate the efficacy of 7-day treatment regimen consisting rifabutin daily but increasing the dose of amoxicillin and lansoprazole in patients who have failed first and second eradication and to assess the side effect profiles in South Korea.

METHODS

From December 2007 to May 2013, 59 H. pylori-infected patients with two previous eradication failures were enrolled for this study prospectively. The eligible patients were randomly assigned to either group A or B. Group A received lansoprazole 30 mg bid, amoxicillin 1.0 g tid and rifabutin 150 mg bid during 7 days, whereas group B received lansoprazole 60 mg bid, amoxicillin 1.0 g tid and rifabutin 150 mg bid during 7 days.

RESULTS

In group A, H. pylori eradication was achieved in 25 (78.1%) of the 32 patients in the ITT analysis and in 25 (80.6%) of the 31 patients in the PP analysis. In group B, H. pylori eradication was achieved in 26 (96.3%) of the 27 patients in the ITT analysis and in 27 (100%) of the 26 patients in the PP analysis. There was statistically significant difference between the two groups in terms of the eradication rates in PP analysis (p = .047), whereas a marginally statistical significance was found in terms of the eradication rates in ITT analysis (p = .051). Reported side effects were mild, and treatment was well tolerated. No major changes in physical examination or in standard laboratory parameters were observed after treatment.

CONCLUSIONS

Rifabutin-based high-dose proton-pump inhibitor (PPI)-combined therapy as empirical rescue treatment is more effective than standard dose PPI-combined rifabutin-based therapy, safe and best tolerable in third-line therapy in the Korean population. The key to successful rescue therapy with rifabutin-amoxicillin-PPI regimen may be to increase doses of PPI.

The Helicobacter pylori resistance rate to clarithromycin in Iran

BACKGROUND

Clarithromycin is the most commonly suggested antibiotic in Helicobacter pylori eradication regimens. Increasing antibiotic resistance rate to clarithromycin is the main reason for therapeutic failure. The resistance is associated with mutations in the 23S rRNA gene.

AIM

The purpose of this study was to determine the clarithromycin resistance rate of isolated H. pylori strains from referral patients in Kashan, Iran.

METHODS

In total 95 H. pylori strains isolated from gastric mucosa of 246 patients with different clinical signs underwent gastroscopy in Kashan, Iran in 2013. The Epsilometer test was used to determine the minimum inhibitory concentrations (MICs) of clarithromycin (CLR) in isolated H. pylori strains. Occurrence of mutation in 23S rRNA gene of clarithromycin-resistant strains was investigated with polymerase chain reaction-sequencing method.

RESULTS

Antibiotic susceptibility pattern showed that 32 strains (33.7%) were resistant to clarithromycin (MICs ≥1 μg/ml), 33.7% were intermediate resistant, while 31 of H. pylori strains (32.6%) were susceptible. The 23S rRNA gene mutations at positions A2143G and A2142G were detected in H. pylori clarithromycin-resistant strains.

CONCLUSION

The resistance rate to clarithromycin in Iran is high. H. pylori clarithromycin-resistant strains were not associated with sex, age, and disease. The A2143G mutation in clarithromycin-resistant H. pylori strains was the predominant finding.

Antimicrobial susceptibility testing for Helicobacter pylori in times of increasing antibiotic resistance

The gram-negative bacterium Helicobacter pylori (H. pylori) causes chronic gastritis, gastric and duodenal ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Treatment is recommended in all symptomatic patients. The current treatment options for H. pylori infection are outlined in this review in light of the recent challenges in eradication success, largely due to the rapid emergence of antibiotic resistant strains of H. pylori. Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H. pylori antibiotic resistance varies significantly from country to country, and even between regions within the same country. In addition, recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H. pylori. Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. Antimicrobial resistance is assessed by H. pylori culture and antimicrobial susceptibility testing. Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H. pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material. Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H. pylori infection.

Practical treatment of Helicobacter pylori: a balanced view in changing times

Eradication rates of first-line triple therapy for Helicobacter pylori infection have fallen in the recent years. The main reasons for treatment failure are poor compliance due to complicated treatment regimens and the emergence of antibiotic-resistant strains of H. pylori. Treatment failure is a cause for concern with regard to the complications of H. pylori infection, which include gastric and peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. This review describes considerations for optimizing standard first-line triple therapy, as well as alternatives to the standard first-line treatment, such as bismuth quadruple therapy, sequential therapy, concomitant therapy and hybrid therapy. Studies using levofloxacin-based and rifabutin-based regimens for the treatment of multiresistant infections have also been reviewed. The current most up-to-date systematic reviews and meta-analyses comparing the efficacy of these treatments have been discussed, in light of the recent antimicrobial susceptibility testing data, regional antibiotic resistance rates and the Maastricht IV guidelines on the management of H. pylori infection.

Culture-based selection therapy for patients who did not respond to previous treatment for Helicobacter pylori infection

BACKGROUND & AIMS

Eradication of Helicobacter pylori using empiric therapy has become difficult as a result of increasing resistance to antibiotics. We evaluated the efficacy of specific treatments, selected based on response of bacterial samples to culture with clarithromycin, levofloxacin, and metronidazole, for patients infected with resistant strains of H pylori.

METHODS

We performed a prospective study at a single center of 236 consecutive patients with persistent H pylori infection, despite 1 or more treatment attempts, and documented resistance to at least 1 antimicrobial agent (based on bacterial culture tests). Biopsy samples were collected by endoscopy and cultured in selective media. Patients received either 10 days of levofloxacin (250 mg twice daily for 131 patients with susceptible infections) or 12 days of rifabutin (150 mg once daily for 105 patients resistant to levofloxacin) in combination with amoxicillin (1 g twice daily) and esomeprazole (40 mg twice daily). Efficacy of eradication was determined by the (13)C-urea breath test, 6 to 8 weeks after therapy. Compliance and side effects were determined via personal interviews at the end of therapy. Rifabutin toxicity was monitored by analysis of blood samples.

RESULTS

H pylori infection was cured in 118 of the patients who received levofloxacin triple therapy (90%; 95% confidence interval, 85%-95%) and 93 of the patients who received rifabutin triple therapy (88.6%; 95% confidence interval, 82%-95%). In each group, the cure rate did not differ significantly between patients infected with H pylori strains resistant to single or multiple antibiotics. Mild side effects occurred in 15.5% and 14.9% of patients resistant to single or multiple antibiotics, respectively, and self-limiting neutropenia was observed in 1 (0.7%) case.

CONCLUSIONS

Selection of triple therapy with either levofloxacin or rifabutin, based on results from bacterial culture tests, cures H pylori infection in about 90% who did not previously respond to antibiotics.

Recent Insights into Antibiotic Resistance in Helicobacter pylori Eradication

Antibiotics have been useful in the treatment of H. pylori-related benign and malignant gastroduodenal diseases. However, emergence of antibiotic resistance often decreases the eradication rates of H. pylori infections. Many factors have been implicated as causes of treatment failure, but the main antibiotic resistance mechanisms described to date are due to point mutations on the bacterial chromosome, a consequence of a significantly phenotypic variation in H. pylori. The prevalence of antibiotic (e.g., clarithromycin, metronidazole, tetracycline, amoxicillin, and furazolidone) resistance varies among different countries; it appears to be partly determined by geographical factors. Since the worldwide increase in the rate of antibiotic resistance represents a problem of relevance, some studies have been performed in order to identify highly active and well-tolerated anti-H. pylori therapies including sequential, concomitant quadruple, hybrid, and quadruple therapy. These represent a promising alternatives in the effort to overcome the problem of resistance. The aim of this paper is to review the current status of antibiotic resistance in H. pylori eradication, highlighting the evolutionary processes in detail at alternative approaches to treatment in the past decade. The underlying resistance mechanisms will be also followed.

Is Helicobacter pylori antibiotic resistance surveillance needed and how can it be delivered?

BACKGROUND

Most patients are prescribed Helicobacter pylori treatment without culture and antibiotic susceptibility testing, as current guidance recommends that patients with recurrent dyspepsia should be tested for H. pylori using a non-invasive breath or faecal antigen test.

AIMS

To determine the prevalence of H. pylori antibiotic resistance in patients attending endoscopy in England and Wales, and the feasibility of an antibiotic resistance surveillance programme testing.

METHODS

We tested the antibiotic susceptibility of H. pylori isolates from biopsy specimens from 2063 of 7791 (26%) patients attending for endoscopy in Gloucester and Bangor, and 339 biopsy specimens sent to the Helicobacter Reference Unit (HRU) in London. Culture and susceptibility testing was undertaken in line with National and European methods.

RESULTS

Helicobacter pylori were cultured in 6.4% of 2063 patients attending Gloucester and Bangor hospitals. Resistance to amoxicillin, tetracycline and rifampicin/rifabutin was below 3% at all centres. Clarithromycin, metronidazole and quinolone resistance was significantly higher in HRU (68%, 88%, 17%) and Bangor isolates (18%, 43%, 13%) than Gloucester (3%, 22%, 1%). Each previous course of these antibiotics is associated with an increase in the risk of antibiotic resistance to that agent [clarithromycin: RR = 1.5 (P = 0.12); metronidazole RR = 1.6 (P = 0.002); quinolone RR = 1.8 (P = 0.01)].

CONCLUSIONS

Helicobacter pylori infection is now uncommon in dyspeptic patients at endoscopy. A surveillance system is feasible and necessary to inform dyspepsia management guidance. Clinicians should take a thorough antibiotic history before prescribing metronidazole, clarithromycin or levofloxacin for H. pylori.

Fourth-line rescue therapy with rifabutin in patients with three Helicobacter pylori eradication failures

BACKGROUND

In some cases, Helicobacter pylori infection persists even after three eradication treatments.

AIM

To evaluate the efficacy of an empirical fourth-line rescue regimen with rifabutin in patients with three eradication failures.

DESIGN

Multicentre, prospective study.

PATIENTS

In whom the following three treatments had consecutively failed: first (PPI + clarithromycin + amoxicillin); second (PPI + bismuth + tetracycline + metronidazole); third (PPI + amoxicillin + levofloxacin).

INTERVENTION

A fourth regimen with rifabutin (150 mg b.d.), amoxicillin (1 g b.d.) and a PPI (standard dose b.d.) was prescribed for 10 days.

OUTCOME

Eradication was confirmed by (13) C-urea breath test 4-8 weeks after therapy. Compliance and tolerance: Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated using a questionnaire.

RESULTS

One-hundred patients (mean age 50 years, 39% men, 31% peptic ulcer/69% functional dyspepsia) were included. Eight patients did not take the medication correctly (in six cases due to adverse effects). Per-protocol and intention-to-treat eradication rates were 52% (95% CI = 41-63%) and 50% (40-60%). Adverse effects were reported in 30 (30%) patients: nausea/vomiting (13 patients), asthenia/anorexia (8), abdominal pain (7), diarrhoea (5), fever (4), metallic taste (4), myalgia (4), hypertransaminasemia (2), leucopenia (<1,500 neutrophils) (2), thrombopenia (<150,000 platelets) (2), headache (1) and aphthous stomatitis (1). Myelotoxicity resolved spontaneously in all cases.

CONCLUSIONS

Even after three previous H. pylori eradication failures, an empirical fourth-line rescue treatment with rifabutin may be effective in approximately 50% of the cases. Therefore, rifabutin-based rescue therapy constitutes a valid strategy after multiple previous eradication failures with key antibiotics, such as clarithromycin, metronidazole, tetracycline and levofloxacin.

Review article: rifabutin in the treatment of refractory Helicobacter pylori infection

BACKGROUND

Even with the current most effective treatment regimens, a relevant proportion of patients will fail to eradicate Helicobacter pylori infection.

AIM

To evaluate the role of rifabutin in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE. Data on the efficacy of rifabutin-containing regimens on H. pylori eradication were combined and meta-analysed using the generic inverse variance method.

RESULTS

Rifabutin shows good in vitro activity against H. pylori. Mean H. pylori rifabutin resistance rate (calculated from 11 studies including 2982 patients) was 1.3% (95% confidence interval = 0.9-1.7%). When only studies including patients naïve to H. pylori eradication treatment were considered, this figure was even lower (0.6%). On the other hand, higher values of rifabutin resistance were calculated (1.59%) when only post-treatment patients were considered. Overall, mean H. pylori eradication rate (intention-to-treat analysis) with rifabutin-containing regimens (1008 patients) was 73% (67-79%). Respective cure rates for second-line (223 patients), third-line (342 patients) and fourth/fifth-line (95 patients) rifabutin therapies were 79% (67-92%), 66% (55-77%) and 70% (60-79%) respectively. For treating H. pylori infection, almost all studies have administered rifabutin 300 mg/day; this dose seems to be more effective than 150 mg/day. The ideal length of treatment remains unclear, but 10- to 12-day regimens are generally recommended. The mean rate of adverse effects was 22% (19-25%). Myelotoxicity is the most significant, although this complication was rare. Until now, all patients have recovered of leucopenia uneventfully in a few days, and there have been no reports of infection or other adverse outcomes related to it.

CONCLUSION

Rifabutin-containing rescue therapy constitutes an encouraging strategy after multiple (usually three) previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline and levofloxacin.

A clinician's guide to salvage therapy for persistent Helicobacter pylori infection

Since its discovery in 1982, Helicobacter pylori has been established as a common cause of gastritis and peptic ulcer disease. H pylori infection is also closely associated with several gastric malignancies and has consequently been designated a human carcinogen. As these associations have become increasingly recognized and pursued, a growing challenge facing today's clinicians is the management of patients with persistent H pylori despite previous attempts to treat the infection. In developed countries, the most popular treatment regimen remains traditional triple therapy consisting of a proton pump inhibitor, clarithromycin, and amoxicillin for 7 to 14 days. Unfortunately, eradication rates with traditional triple therapy are disappointing, with infection persisting in as many as 25% of those treated. This article addresses the management of patients with persistent H pylori infection, including indications for confirmatory testing, reasons for treatment failure, and established and emerging salvage regimens for patients with persistent infection.

Efficacy of four different moxifloxacin-based triple therapies for first-line H. pylori treatment

Moxifloxacin has been used in the first-line treatment of Helicobacter pylori infection. The optimal dosage and duration have not been assessed.

AIM

To evaluate the effectiveness of moxifloxacin, amoxicillin and esomeprazole in four regimens, in previously untreated patients infected by H. pylori.

METHODS AND PATIENTS

Patients were randomly assigned to: esomeprazole 20 mg b.i.d., amoxicillin 1g b.i.d., and one of each of the four following dosages of moxifloxacin: moxifloxacin 400 mg b.i.d. for 10 days (EAM800x10), moxifloxacin 400 mg b.i.d. for 7 days (EAM800x7), moxifloxacin 400 mg b.i.d. for 5 days (EAM800x5), moxifloxacin 400 mg o.i.d. for 10 days (EAM400x10). Eradication was assessed by the Urea Breath Test (UBT) 2 months following the end of therapy.

RESULTS

Ninety-four, 102, 92 and 105 patients were recruited in EAM800x10, EAM800x7, EAM800x5, and EAM400x10 respectively. The eradication rate was for Intention-To-Treat (ITT) and Per Protocol (PP) analyses: EAM800x10 group ITT: 90.4%, PP: 94.4%; EAM800x7 group ITT: 80.3%, PP: 86.3%; EAM800x5 group ITT: 71.4%, PP: 75.2%; EAM400x10 group ITT: 80.0%, PP 84.8%. A statistically significant difference was reached between EAM800x10 vs. EAM800x7 (ITT and PP: P<0.05), and between EAM800x10 vs. EAM800x5 (ITT and PP: P<0.01) and vs. EAM400x10 (ITT: P<0.05; PP: P<0.04). Thirty patients treated unsuccessfully with EAM800x5 and EAM400x10 were re-treated with EAM800x10 with an eradication rate of 86.7% (ITT) and 92.2% (PP). Nineteen patients with positive UBT after EAM800x10 and EAM800x7 underwent a second-line rifabutin-based therapy with an eradication rate of 84.2% (ITT and PP).

CONCLUSION

A triple therapy with 800 mg of moxifloxacin a day for 10 days is more effective than the same treatment for 5 or 7 days and a treatment with 400mg of moxifloxacin a day for 10 days for the first-line eradication of H. pylori infection. The high cost of moxifloxacin-based treatment however, may limit its wide use as first-line treatment of H. pylori infection.

Second-line rescue therapy of helicobacter pylori infection

Helicobacter pylori infection is the main known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. After more than 20 years of experience in H. pylori treatment, however, the ideal regimen to treat this infection has still to be found. Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a 'rescue' treatment depends on which treatment is used initially. If a first-line clarithromycin-based regimen was used, a second-line metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third-line 'rescue' option. Alternatively, it has recently been suggested that levofloxacin-based 'rescue' therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, quadruple regimen may be reserved as a third-line 'rescue' option. Finally, rifabutin-based 'rescue' therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several 'rescue' therapies are consecutively given. Therefore, the attitude in H. pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Frequency and molecular characteristics of ciprofloxacin- and rifampicin-resistant Helicobacter pylori from gastric infections in the UK

Treatment failure with standard Helicobacter pylori eradication regimes may require the use of 'rescue' therapies containing fluoroquinolones or rifamycins. The susceptibilities of H. pylori in the UK to such antimicrobials are unknown; therefore, this study aimed to determine the frequencies and molecular markers of resistance. Ciprofloxacin and rifampicin susceptibilities were determined by Etest and/or disc diffusion for 255 isolates of H. pylori, including 171 isolates from adult dyspeptic patients with refractive infections. Mutations in known resistance-determining regions of gyrA and rpoB were determined. The ciprofloxacin resistance rate was 7.5 %, and gyrA mutations, predominantly at codon position 91, were identified in most resistant isolates. One isolate (<1 %) had an unequivocal rifampicin-resistant phenotype by Etest yet had no associated mutations in the rpoB gene. As resistance rates were low in H. pylori isolates, including those from patients with refractive infections, it was concluded that fluoroquinolones or rifamycins might be considered in the UK for inclusion in 'rescue' therapies.

Identification and molecular characterization of triple- and quadruple-resistant Helicobacter pylori clinical isolates in Germany

OBJECTIVES

The aim of this study was to estimate the frequency of triple- and quadruple-resistant Helicobacter pylori isolated in Germany, to characterize those isolates molecular genetically and to identify risk factors for the development of multiresistance.

METHODS

Antimicrobial susceptibility to metronidazole, clarithromycin, amoxicillin, tetracycline, ciprofloxacin/levofloxacin and rifampicin in 1118 clinical isolates obtained between July 2006 and December 2007 was tested by the Etest method. For patients harbouring triple- or quadruple-resistant strains (n = 169), data on prior eradication therapies and underlying diseases were collected and evaluated. A select number of quadruple- and triple-resistant strains were examined for resistance-mediating mutations in their 23S rRNA, 16S rRNA, gyrA and rpoB genes, respectively.

RESULTS

From 1118 clinical isolates, 13.4% (n = 150) showed phenotypic resistance to metronidazole, clarithromycin and quinolones and 0.9% (n = 10) to metronidazole, clarithromycin and rifampicin; one isolate exhibited resistance to clarithromycin, quinolones and rifampicin. In eight isolates (0.7%), we detected phenotypic quadruple resistance to metronidazole, clarithromycin, quinolones and rifampicin or tetracycline. Triple- and quadruple-resistant strains harboured resistance-associated mutations in their 23S rRNA, 16S rRNA, gyrA or rpoB genes and were nearly exclusively isolated from patients who had already been unsuccessfully treated on multiple occasions.

CONCLUSIONS

We show that more than 15% of H. pylori strains isolated from routine samples in the German National Reference Centre are resistant to three or more antimicrobials and identified prior unsuccessful eradication therapies as a key factor for the development of multiresistance. Our data emphasize the need for further comprehensive surveillance studies monitoring the role of treatment regimens in antimicrobial resistance in H. pylori.

Emerging therapies for the treatment of Helicobacter pylori infections

OBJECTIVE

To describe emerging therapies, such as levofloxacin, moxifloxacin, rifabutin, rifaximin, tinidazole, doxycycline, minocycline, lactoferrin, and plaunotol for the eradication of Helicobacter pylori infection.

DATA SOURCES

Relevant information was identified through a search of MEDLINE (1966-July 2008), PubMed (1955-July 2008), American Search Premier (1975-July 2008), International Pharmaceutical Abstracts (1960-2008), Science Citation Index Expanded (1996-2008), Cochrane Databases (publications archived until July 2008), and various tertiary sources using the terms Helicobacter pylori, fluoroquinolones, levofloxacin, moxifloxacin, rifabutin, rifaximin, lactoferrin, plaunotol, tinidazole, doxycycline, minocycline, faropenem, new treatments, refractory, and salvage alone or in combination.

STUDY SELECTION AND DATA EXTRACTION

Relevant information was identified and selected based on clinical relevance and value of information. In vitro and in vivo data were included if available.

DATA SYNTHESIS

Data exist supporting the use of levofloxacin or rifabutin as salvage therapies for H. pylori infection. Levofloxacin triple therapy has been recommended in the current treatment guideline, but more data are needed, especially from studies conducted in the US. A rifabutin-based regimen is better tolerated than conventional quadruple therapy, but its use is limited due to cost, hematologic adverse effects, drug interactions, and predicted development of resistance. Tinidazole appears to be an option, particularly as sequential therapy when combined with other agents; however, its use is limited by the high prevalence of nitroimidazole-resistant H. pylori strains in the US. Moxifloxacin data are limited. Data supporting the use of rifaximin, doxycycline, and minocycline are lacking or do not show benefit of these drugs over standard treatments.

CONCLUSIONS

H. pylori infection remains one of the most significant infections worldwide, and treatment failure rate with the current standard therapy continues to rise. Other treatment options should be explored to meet the emerging challenge.

“Rescue” regimens after Helicobacter pylori treatment failure

Helicobacter pylori (H pylori) infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. After more than 20 years of experience in H pylori treatment, in my opinion, the ideal regimen to treat this infection is still to be found. Currently, apart from having to know first-line eradication regimens well, we must also be prepared to face treatment failures. Therefore, in designing a treatment strategy we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of a “rescue” treatment depends on which treatment is used initially. If a clarithromycin-based regimen was used initially, a subsequent metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third “rescue” option. Alternatively, it has recently been suggested that levofloxacin-based rescue therapy constitutes an encouraging second-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, a quadruple regimen may be reserved as a third-line rescue option. Finally, rifabutin-based rescue therapy constitutes an encouraging empirical fourth-line strategy after multiple previous eradication failures with key antibiotics such as amoxicillin, clarithromycin, metronidazole, tetracycline, and levofloxacin. Even after two consecutive failures, several studies have demonstrated that H pylori eradication can finally be achieved in almost all patients if several rescue therapies are consecutively given. Therefore, the attitude in H pylori eradication therapy failure, even after two or more unsuccessful attempts, should be to fight and not to surrender.

Efficacy of rifabutin-based triple therapy as second-line treatment to eradicate helicobacter pylori infection

Background

Rifabutin has been found to be effective in multi-resistant patients after various treatment cycles for Helicobacter pylori (HP) infection, but it has not been analysed as a second-line treatment. Therefore, we seek to compare the effectiveness of a treatment regimen including rifabutin versus conventional quadruple therapy (QT).

Methods

Open clinical trial, randomised and multi-centre, of two treatment protocols: A) Conventional regime -QT- (omeprazole 20 mg bid, bismuth citrate 120 mg qid, tetracycline 500 mg qid and metronidazole 500 mg tid); B) Experimental one -OAR- (omeprazole 20 mg bid, amoxicillin 1 gr bid, and rifabutin 150 mg bid), both taken orally for 7 days, in patients with HP infection for whom first-line treatment had failed. Eradication was determined by Urea Breath Test (UBT). Safety was determined by the adverse events.

Results

99 patients were randomised, QT, n = 54; OAR, n = 45. The two groups were homogeneous. In 8 cases, treatment was suspended (6 in QT and 2 in OAR). The eradication achieved, analysed by ITT, was for QT, 38 cases (70.4%), and for OAR, 20 cases (44.4%); p = 0.009, OR = 1.58. Of the cases analysed PP, QT were 77.1%; OAR, 46.5%; p = 0.002. Adverse effects were described in 64% of the QT patients and in 44% of the OAR patients (p = 0.04).

Conclusion

A 7-day rifabutin-based triple therapy associated to amoxicillin and omeprazole at standard dose was not found to be effective as a second-line rescue therapy. The problem with quadruple therapy lies in the adverse side effects it provokes. We believe the search should continue for alternatives that are more comfortably administered and that are at least as effective, but with fewer adverse side effects.

Trial Registration

Current Controlled Trials ISRCTN81058036

Characterization of rifampicin-resistant clinical Helicobacter pylori isolates from Germany

OBJECTIVES

The aim of this study was to assess the rate of rifampicin resistance in Helicobacter pylori isolated from patients in Germany, to detect rifampicin resistance-associated mutations and to identify non-resistance-associated genetic variants in the rpoB gene.

METHODS

Susceptibility to rifampicin in a total of 1585 clinical isolates obtained between January 2003 and July 2006 was tested by disc diffusion and/or by the Etest method. The rpoB genes of a selection of both resistant (n=17) and susceptible (n=100) clinical isolates were sequenced in order to distinguish between resistance- and non-resistance-associated genetic alterations. In vitro mutagenesis experiments such as site-directed mutagenesis were carried out to demonstrate the pivotal role of rpoB mutations in rifampicin resistance.

RESULTS

From 1585 clinical isolates examined, 22 (1.4%) showed phenotypic resistance to rifampicin (MIC>4 mg/L). The majority of the resistant strains harboured point mutations in their rpoB genes at codons 530, 540 and 545 and showed cross-resistance to rifabutin. Four clinical isolates with moderate rifampicin resistance (8 mg/L) showed a rifabutin-susceptible phenotype and did not harbour any mutation in the sequenced rpoB fragments. Sequence analysis of 100 rifampicin-susceptible isolates revealed numerous novel silent mutations in the rpoB genes resulting in amino acid exchanges, but not in resistance.

CONCLUSIONS

Resistance to rifampicin/rifabutin in H. pylori strains isolated in Germany is still low and is associated with mutations in the rpoB gene. Further surveillance studies analysing the use of rifabutin in H. pylori eradication and its association with the occurrence of rifabutin-resistant strains are required.

Effective regimens for the treatment of Helicobacter pylori infection

Successful Helicobacter pylori eradication therapy remains a challenge in medical practice. Currently, a proton pump inhibitor-based triple therapy containing clarithromycin, amoxicillin or nitroimidazole for 7 days is the recommended first-line treatment approach with an expected eradication success rate of approximately 80%. As a second-line treatment option in the case of failure, a ranitidine bismuth citrate-based quadruple therapy is currently recommended curing another 80% of patients, leaving a subset of patients with persistent H. pylori infection. For these patients, promising rescue options have been evaluated including regimens that contain rifabutin, quinolones, furazolidone or high-dose amoxicillin. The role of susceptibility testing is still under discussion. It is not generally recommended prior to first-line treatment but guidelines propose a role for culture and antibiotic sensitivity testing after failure of the second attempt. Meanwhile, data on the geographic distribution of resistance pattern are available and may guide therapeutic decisions with regard to the combination of antibiotics chosen for the individual patients aiming at 100% cure rate in each individual patient.

Role of the preliminary susceptibility testing for initial and after failed therapy of Helicobacter pylori infection with levofloxacin, amoxicillin, and esomeprazole

BACKGROUND

Levofloxacin has been proposed as an alternative to classic therapy in secondary resistance to Helicobacter pylori.

AIM

To evaluate primary and secondary resistance of H. pylori to levofloxacin, and to test the role of susceptibility test on the efficacy of levofloxacin-based triple therapy.

METHODS

Eighty consecutive dyspeptic patients with positive (13)C-urea breath test never treated were randomly allocated into group A(1) (40 patients) and group B(1) (39 patients). Eighty-three patients already treated unsuccessfully with positive (13)C-urea breath test were divided into group A(2) (51 patients) and group B(2) (32 patients). Patients in group A(1) and group A(2) underwent upper gastrointestinal endoscopy for H. pylori susceptibility test to amoxicillin, clarithromycin, tinidazole, rifabutin, and levofloxacin. These patients were treated with levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and esomeprazole (20 mg b.i.d.) for 10 days if sensitive to these two antibiotics. If H. pylori was found resistant to amoxicillin and/or levofloxacin the treatment was based on the indications of the susceptibility test. Patients in group B(1) and group B(2) were treated empirically with levofloxacin, amoxicillin, and esomeprazole at the same dose and duration as group A. All patients underwent (13)C-urea breath test 2 months after the end of therapy.

RESULTS

The antibiotic resistance of H. pylori strains in group A(1) and group A(2) was (%): amoxicillin: 2.4, 10; clarithromycin: 21.9, 43.1; tinidazole: 31.7, 70; rifabutin: 2.4, 4; and levofloxacin: 9.7, 12.2, respectively. In group A(1) with susceptibility test-driven therapy, eradication was 97.2%, and in group B(1) with empirical treatment, 94.1% (n.s.). In group A(2) with susceptibility test, eradication was 97.5%, whereas in group B(2) with empirical treatment 81.2% (p < .01).

CONCLUSION

Primary and secondary resistance of H. pylori to levofloxacin is approximately 10% of the tested strains. The susceptibility test does not influence therapeutic outcome of triple therapy with amoxicillin and levofloxacin in patients never treated, while it is determinant for patients who were previously treated without success.

Randomized trial of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

BACKGROUND

The clinical management of Helicobacter pylori infected patients who failed standard eradication therapies remains a challenge.

AIM

To investigate the efficacy of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of H. pylori, and the correlation between cytochrome P450 2C19 (CYP2C19) polymorphisms and treatment outcome.

METHODS

Patients infected with H. pylori resistant to both metronidazole and clarithromycin (n = 145) were randomized to either esomeprazole 20 mg, rifabutin 150 mg and amoxicillin 1 g, each given b.d. for 7 days (ERA), or to omeprazole 40 mg and amoxicillin 1000 mg, each given t.d.s. for 14 days (OA). Crossover therapy was offered in cases of persistent infection. CYP2C19 polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism.

RESULTS

Intention-to-treat and per-protocol eradication rates were: ERA 74% (62.4-83.6) and 78% (66.7-87.3); high-dose OA 70% (57.5-79.7) and 75% (62.5-84.5). Crossover therapy was successful in seven of 10 patients with ERA and in eight of 10 patients with OA. Premature discontinuation of treatment occurred in 2% and 5% of patients, respectively. There was only a non-significant trend to lower eradication rates in homozygous extensive metabolizers.

CONCLUSIONS

Triple therapy with esomeprazole, rifabutin and amoxicillin and high-dose omeprazole/amoxicillin are comparable and effective and safe for rescue therapy of H. pylori regardless of the patient's CYP2C19 genotype.

Effects of combining extracts (from propolis or Zingiber officinale) with clarithromycin on Helicobacter pylori

Propolis and Zingiber officinale have been shown to be specifically targeted against Helicobacter pylori strains, to possess antiinflammatory, antioxidant and antitumoral activity and to be used in traditional medicine for the treatment of gastrointestinal ailments. Considering that these natural products could potentially serve as novel therapeutic tools also in combination with an antibiotic, the aim of this work was to evaluate their effect when combined with clarithromycin on clinical H. pylori isolates (n = 25), characterized in respect to both clarithromycin susceptibility and the presence of the cagA gene. The results showed that the combinations of propolis extract + clarithromycin and Z. officinale extract + clarithromycin exhibited improved inhibition of H. pylori with synergistic or additive activity. Interestingly, the susceptibility to combinations was significantly independent of the microbial clarithromycin susceptibility status. Only one H. pylori strain showed antagonism towards the Z. officinale extract + clarithromycin combination. The data demonstrate that combinations of propolis extract + clarithromycin and Z. officinale extract + clarithromycin have the potential to help control H. pylori-associated gastroduodenal disease.

Analysis of genetic variability, antimicrobial susceptibility and virulence markers in Helicobacter pylori identified in Central Italy

OBJECTIVE

To assess the relationship between the presence of mixed infection of Helicobacter pylori and both antimicrobial susceptibility and virulence markers.

MATERIAL AND METHODS

Thirty-six patients with H. pylori infection were included in the study. Three colonies were selected from each positive biopsy sample collected from each host for a total of 108 H. pylori strains. The genetic variability was evaluated through the amplified fragment length polymorphism (AFLP) analysis; the antibiotic susceptibility to amoxicillin, clarithromycin, moxifloxacin, rifabutin and tinidazole was determined using the minimum inhibitory concentrations (MICs) with the agar dilution method. Moreover, the vacA, cagA, iceA and babA2 statuse were detected by polymerase chain reaction (PCR).

RESULTS

There was a strong connection between mixed H. pylori infection and antimicrobial resistance. In particular, H. pylori strains with genetic variability, in the same host, expressed more resistance to clarithromycin, moxifloxacin and tinidazole than that expressed in strains with a unique genetic host pattern. VacA s1m1/s1m2 genotypes were found in 70% of strains isolated in mixed infection, whereas the same allelic combinations were found in 42% of strains, isolated in single infection. The cagA(+) status prevailed both in patients with mixed (97%) and in those with single infection (85%) without significant differences. The iceA1 status was more commonly found in patients with mixed infection, whereas the babA2 status was significantly prevalent in single H. pylori infection.

CONCLUSIONS

Mixed H. pylori infection harbouring in one patient is significantly related to strains that are more resistant to antibiotics and with a more virulent genotype (vacA s1m1/s1m2, cagA, iceA1) than strains responsible for single infection.