The relationship between consumption of antimicrobial agents and the prevalence of primary Helicobacter pylori resistance

Rapid diagnosis and precision treatment of Helicobacter pylori infection in clinical settings

Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of approximately half of the worldwide population, with higher prevalence in densely populated areas like Asia, the Caribbean, Latin America, and Africa. H. pylori infections range from asymptomatic cases to potentially fatal diseases, including peptic ulcers, chronic gastritis, and stomach adenocarcinoma. The management of these conditions has become more difficult due to the rising prevalence of drug-resistant H. pylori infections, which ultimately lead to gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. In 1994, the International Agency for Research on Cancer (IARC) categorized H. pylori as a Group I carcinogen, contributing to approximately 780,000 cancer cases annually. Antibiotic resistance against drugs used to treat H. pylori infections ranges between 15% and 50% worldwide, with Asian countries having exceptionally high rates. This review systematically examines the impacts of H. pylori infection, the increasing prevalence of antibiotic resistance, and the urgent need for accurate diagnosis and precision treatment. The present status of precision treatment strategies and prospective approaches for eradicating infections caused by antibiotic-resistant H. pylori will also be evaluated.

Tailored triple plus bismuth therapy based on previous antibiotic medication history for first-line Helicobacter pylori eradication: A randomized trial

INTRODUCTION

There are no randomized controlled trials that demonstrate the role of tailored therapy based on past medication history in improving efficacy of H. pylori eradication compared to empiric therapies. The objective of this study was to determine whether tailored triple plus bismuth therapy (TBT) can achieve higher eradication rates based on previous antibiotic history than empiric TBTs.

METHODS

800 treatment-naïve patients were randomly assigned to four groups receiving clarithromycin-, levofloxacin- or metronidazole-containing empiric TBT and tailored TBT (clarithromycin and levofloxacin chosen based on previous macrolides and quinolones medication history). Correlation analyses were performed between past medication history and resistance or eradication rate.

RESULTS

The eradication rates of tailored TBT were significantly higher than clarithromycin-, levofloxacin- and metronidazole-containing empiric TBT in both intention-to-treat (89.5%, 80.8%, 81.5% and 81.5%) and per-protocol (95.1%, 86.7%, 86.5% and 87.8%) analyses (P<0.05). In patients with previous macrolides, quinolones or nitroimidazoles medication history, the resistance rates of corresponding clarithromycin, levofloxacin or metronidazole were significantly higher than patients without past medication history, and the eradication rates of corresponding clarithromycin- or levofloxacin-containing empiric TBT were significantly lower.

CONCLUSION

Tailored TBT based on previous antibiotic history can achieve higher eradication rates than empiric TBT for first-line H. pylori eradication.

Geospatial analysis of Helicobacter pylori infection in South Australia: Should location influence eradication therapy?

BACKGROUND AND AIM

Rates of antimicrobial-resistant Helicobacter pylori infection are rising globally; however, geospatial location and its interaction with risk factors for infection have not been closely examined.

METHODS

Gastric biopsy specimens were collected to detect H. pylori infection at multiple centers in Adelaide, South Australia, between 1998 and 2017. The geospatial distribution of antibiotic-resistant H. pylori in the Greater Adelaide region was plotted using choropleth maps. Moran's I was used to assess geospatial correlation, and multivariate linear regression (MLR) was used to examine associations between migration status, socioeconomic status, age, gender, and rates of H. pylori positivity and antibiotic resistance. Geographically weighted regression (GWR) was used to determine the extent to which the associations varied according to geospatial location.

RESULTS

Of 20 108 biopsies across 136 postcodes within the Greater Adelaide region, 1901 (9.45%) were H. pylori positive. Of these, 797 (41.9%) displayed clarithromycin, tetracycline, metronidazole, or amoxicillin resistance. In MLR, migration status was associated with the rate of H. pylori positivity (β = 3.85% per 10% increase in a postcode's migrant population; P < 0.001). H. pylori positivity and resistance to any antibiotic were geospatially clustered (Moran's I = 0.571 and 0.280, respectively; P < 0.001 for both). In GWR, there was significant geospatial variation in the strength of the migrant association for both H. pylori positivity and antibiotic resistance.

CONCLUSION

Our study demonstrates the heterogeneous geospatial distribution of H. pylori positivity and antibiotic resistance, as well as its interaction with migrant status. Geographic location and migrant status are important factors to consider for H. pylori eradication therapy.

Helicobacter pylori diagnosis and therapy in the era of antimicrobial stewardship

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

Antibiotic resistances and eradication rates in Helicobacter pylori infection

INTRODUCTION

The resistance to antibiotics of Helicobacter pylori (H. pylori) is the main factor that affects current therapeutic treatments. The main objective of this study is to describe the pattern of antibiotic resistances in children with an infection due to H. pylori.

PATIENTS AND METHODS

An observational, retrospective study was conducted from 2014 to 2019, which included patients between 5 and 17 years old, on whom a gastroscopy, with a gastric biopsy culture positive for H. pylori, and an antibiotic sensitivity study was performed. The antibiotic sensitivity studies were performed using an epsilometer (E-test). The cut-off points to define the resistances were those proposed by the European Committee on Antimicrobial Susceptibility Testing - EUCAST. The eradication study was performed using the 13C-urea breath test or the H. pylori monoclonal test in faeces 6-8 weeks after finalising the treatment.

RESULTS

The study included 80 patients (63.8% females), with a mean age of 11.9 years (SD ± 2.7 DS). Over one-third (38.8%) of the patients had received previous treatment for H. pylori. In the endoscopy, peptic ulcer lesions were observed in 10% of patients. More than two-thirds (67.5%) had resistance to at least one drug. 16.3% presented double resistance. The primary resistances were: clarithromycin, 44.9%, metronidazole 16.3%, levofloxacine 7.9%, and amoxicillin 2%. Patients that received treatment according to the new ESPGHAN 2017 guidelines had significantly higher eradication rates compared to those that received treatment according to previous guidelines (80% vs. 55.8%, P = 0.04).

CONCLUSIONS

The high rate of H. pylori resistances, and as a result, the low eradication rates, are still a very important cause for concern. The first line treatment, when this is indicated must be given following the antibiotic sensitivity studies, and in the cases where these cannot be done or are not available, at least in accordance with the regional resistance rates. The correct application of the new guidelines significantly improves the eradication rate.

Comparing the Effect of Two Low-dose and High-dose Four-drug Regimens of Furazolidone in Eradicating Helicobacter Pylori

BACKGROUND Antibiotic resistance is a major cause of Helicobacter pylori (H. pylori ) treatment failures. The increased resistance to clarithromycin and metronidazole has reduced the ability of this therapeutic regimen and prompted researchers to look for other drugs. One of the antibiotics of interest in this regard is furazolidone because of its low drug resistance. The aim of this study is compare two-drug regimens including low-dose and high-dose furazolidone in the treatment of H. pylori. METHODS This study is a clinical trial in which the studied subjects were categorized into two groups. The first group underwent treatment with amoxicillin 1000 mg-BD, furazolidone 100 mg-BD, omeprazole 20 mg-BD, and bismuth subcitrate 240 mg-BD for two weeks (low-dose OFAB). The second group received furazolidone 200 mg-BD (high-dose OFAB). Then eight weeks after completion of the treatment, they were examined in terms of eradication via the UBT test. RESULTS 85 participants completed the study in each group. The response to treatment was 76% and 83% in the low and high-dose groups, respectively, based on intention to treat analysis. Based on per protocol analysis the response to treatment was 78% and 84%, respectively, if excluded patients had completed their protocol and had response to treatment, and 72% and 79%, respectively, if excluded patients had completed their protocol and did not have response to treatment (p = 0.298). In the low-dose and high-dose groups, 16.5% and 24.7% of the participants suffered the complications of treatment with furazolidone (p = 0.18), respectively. Three patients in the high-dose group and one in the low-dose group did not complete the treatment because of the medication's bad taste (p = 0.03). CONCLUSION Low doses of furazolidone had a comparable therapeutic effect compared with high doses, but patients experienced significantly lower levels of bad taste, which was a major cause of reluctance to continue treatment. Therefore, we think four-drug low-dose furazolidone treatment is a good choice in eradicating H. pylori.

Primary and secondary clarithromycin resistance in Helicobacter pylori and mathematical modeling of the role of macrolides

Clarithromycin is a macrolide antibiotic widely used for eradication of Helicobacter pylori infection, and thus resistance to this antibiotic is a major cause of treatment failure. Here, we present the results of a retrospective observational study of clarithromycin resistance (Cla-res) in 4744 H. pylori-infected patients from Central Hungary. We use immunohistochemistry and fluorescence in situ hybridization on fixed gastric tissue samples to determine H. pylori infection and to infer Cla-res status, respectively. We correlate this information with macrolide dispensing data for the same patients (available through a prescription database) and develop a mathematical model of the population dynamics of Cla-res H. pylori infections. Cla-res is found in 5.5% of macrolide-naive patients (primary Cla-res), with no significant sex difference. The model predicts that this primary Cla-res originates from transmission of resistant bacteria in 98.7% of cases, and derives from spontaneous mutations in the other 1.3%. We find an age-dependent preponderance of female patients among secondary (macrolide-exposed) clarithromycin-resistant infections, predominantly associated with prior use of macrolides for non-eradication purposes. Our results shed light into the sources of primary resistant cases, and indicate that the growth rate of Cla-res prevalence would likely decrease if macrolides were no longer used for purposes other than H. pylori eradication.

Antimicrobial resistance of Helicobacter pylori in an eastern German region

BACKGROUND

Antimicrobial therapy is recommended to eradicate Helicobacter (H.) pylori in infected individuals. As first-line treatments are empiric, knowledge of antimicrobial resistance is key to successful eradication.

AIMS

We investigated primary resistance in an eastern German region to derive recommendations for eradication treatment.

METHODS

We used molecular genetic methods to examine Helicobacter rapid urease test (RUT) positive gastric specimens of 533 patients from Berlin and the federal state of Brandenburg with allegedly no prior eradication treatment. Tissue samples were removed from RUT and screened by real-time PCR for mutations conferring resistance to clarithromycin. In addition, 182 samples out of 533 were tested for resistance to levofloxacin and tetracycline.

RESULTS

Primary resistances were 10.9% (58 out of 533) to clarithromycin; 13.7% (25/182) to levofloxacin; and 2.2% to tetracycline (4/182). Combined resistance to clarithromycin/levofloxacin was low (2.2%, 4/182). Female sex was significantly associated with clarithromycin resistance.

CONCLUSION

Clarithromycin may be a suitable first-line antibiotic for about 90% of outpatients. A simple molecular test may help physicians avoid prescription of an ineffective first-line regimen.

[Antibiotic resistances and eradication rates in Helicobacter pylori infection]

INTRODUCTION

The resistance to antibiotics of Helicobacter pylori (H. pylori) is the main factor that affects current therapeutic treatments. The main objective of this study is to describe the pattern of antibiotic resistances in children with an infection due to H. pylori.

PATIENTS AND METHODS

An observational, retrospective study was conducted from 2014 to 2019, which included patients between 5 and 17 years old, on whom a gastroscopy, with a gastric biopsy culture positive for H. pylori, and an antibiotic sensitivity study was performed. The antibiotic sensitivity studies were performed using an epsilometer (E-test). The cut-off points to define the resistances were those proposed by the European Committee on Antimicrobial Susceptibility Testing - EUCAST. The eradication study was performed using the 13C-urea breath test or the H. pylori monoclonal test in faeces 6-8 weeks after finalising the treatment.

RESULTS

The study included 80 patients (63.8% females), with a mean age of 11.9 years (SD±2.7DS). Over one-third (38.8%) of the patients had received previous treatment for H. pylori. In the endoscopy, peptic ulcer lesions were observed in 10% of patients. More than two-thirds (67.5%) had resistance to at least one drug. 16.3% presented double resistance. The primary resistances were: clarithromycin, 44.9%, metronidazole 16.3%, levofloxacine 7.9%, and amoxicillin 2%. Patients that received treatment according to the new ESPGHAN 2017 guidelines had significantly higher eradication rates compared to those that received treatment according to previous guidelines (80% vs. 55.8%, P=.04).

CONCLUSIONS

The high rate of H.pylori resistances, and as a result, the low eradication rates, are still a very important cause for concern. The first line treatment, when this is indicated must be given following the antibiotic sensitivity studies, and in the cases where these cannot be done or are not available, at least in accordance with the regional resistance rates. The correct application of the new guidelines significantly improves the eradication rate.

Vonoprazan-based triple therapy is effective for Helicobacter pylori eradication irrespective of clarithromycin susceptibility

BACKGROUND

Helicobacter pylori causes peptic ulcers and accounts for over 90% of gastric cancers; however, eradication rates have been declining due to antimicrobial resistance. Vonoprazan (VPZ), a potassium-competitive acid blocker, produces rapid and profound gastric acid suppression and has shown promising effects in the improvement of H. pylori eradication rates. The efficacy and safety of VPZ-based triple therapy as a first-line regimen for H. pylori eradication and its relationship with clarithromycin (CAM) susceptibility were evaluated.

METHODS

From May 2015 to September 2017, H. pylori-infected patients who underwent esophagogastroduodenoscopy with CAM susceptibility testing were prospectively enrolled. Patients received a 7-day triple therapy regimen (VAC) of VPZ (20 mg), amoxicillin (750 mg), and CAM (200 mg) twice daily. Eradication rates, demographics, CAM susceptibility, and safety profiles were assessed.

RESULTS

VAC was administered to 146 patients (median age: 63, range: 22-85 years) (60% of whom were females) who underwent CAM susceptibility testing, and 131 patients underwent ¹³C-urea breath testing to evaluate eradication success. The prevalence of CAM resistance was 34.2%. The overall eradication rates of VAC in per protocol (PP) and "intention to treat" (ITT) analyses were 90.8% (n = 131) and 81.5% (n = 146), respectively. In PP analysis for CAM susceptibility, the eradication rates of VAC were comparable between CAM-sensitive (91.6%, n = 83) and CAM-resistant (89.4%, n = 47) strains. The corresponding rates from the ITT analysis were 80.0% (n = 95) and 84.0% (n = 50), respectively. No adverse events requiring discontinuation of VAC were observed.

CONCLUSIONS

CAM-resistant H. pylori was prevalent in one-third of patients in the Tokyo metropolitan area. VPZ-based triple therapy was highly effective and well-tolerated irrespective of CAM susceptibility. Therefore, it could be a valuable first-line treatment regimen for H. pylori infection.

[Antibiotic resistance of Helicobacter pylori in the European part of the Russian Federation: first results]

AIM

Determine the primary antibiotic resistance of Helicobacter pylori (H. pylori) strains isolated from patients living in the European part of the Russian Federation.

MATERIALS AND METHODS

As part of a clinical laboratory study, from 2015 to 2018, 27 gastrobiopsy samples obtained from H. pylori-infected patients were analyzed. H. pylori infection was verified using a rapid urease test or a 13C-urea breath test. The values of the minimum inhibitory concentration (MIC) of antibiotics were determined by the diffusion method using E-test strips (BioMerieux, France) according to the recommendations of the manufacturer. The sensitivity of the isolates was determined for 6 antibacterial drugs (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, rifampicin).

RESULTS

According to the data obtained, resistance to amoxicillin was 0%, clarithromycin 11.1%, metronidazole 59.3%, levofloxacin 3.7%, tetracycline 0%, and rifampicin 14.8%. Dual resistance to clarithromycin and metronidazole was recorded in two isolates (7.4%).

CONCLUSION

Thus, the first results of the evaluation of H. pylori antibiotic resistance in the European part of the Russian Federation indicate a low resistance of the microorganism to clarithromycin and quite high to metronidazole.

Impact of previous metronidazole exposure on metronidazole-based second-line quadruple therapy for Helicobacter pylori infection

BACKGROUND/AIMS

The negative effects on the eradication success of Helicobacter pylori infection after previous exposure to macrolides, including clarithromycin on clarithromycin-based first-line therapy have been demonstrated. However, whether this is true for metronidazole-based second-line quadruple therapy remains unclear. We investigated the relationship between past administration of metronidazole and the failure of metronidazole-based second-line quadruple therapy in patients with H. pylori infection.

METHODS

Patients over 20 years of age who were diagnosed with H. pylori infection between January 1998 and March 2016 were enrolled in this study. The relationship between the clinical parameters and the results of a C13-urea breath test after metronidazole-based second-line quadruple therapy was analyzed in patients for whom clarithromycin-based triple therapy failed to eradicate H. pylori.

RESULTS

The H. pylori eradication failure rate was significantly higher in patients with a history of metronidazole use than in patients without a history of metronidazole use (p = 0.011). Multivariable analysis showed that the odds ratio of previous metronidazole use for eradication failure was 3.468 (95% confidence interval, 1.391 to 8.649; p = 0.008). In the subgroup analysis of patients with a history of metronidazole use, the duration of metronidazole use and interval between its use and eradication therapy did not significantly affect H. pylori eradication failure.

CONCLUSION

Previous exposure to metronidazole was a significant risk factor for treatment failure of metronidazole-based second-line quadruple therapy; therefore, this should be considered when establishing a treatment strategy for patients with H. pylori infection.

Efficacy of tailored second-line therapy of Helicobacter pylori eradication in patients with clarithromycin-based treatment failure: a multicenter prospective study

BACKGROUND

After the failure of clarithromycin- and bismuth-based quadruple therapy (CBQT), levofloxacin- and bismuth-based quadruple therapy (LBQT) is recommended for Helicobacter pylori eradication. We compared the efficacies of second-line tailored bismuth-based quadruple therapy (TBQT) and empirical LBQT.

METHODS

Patients with CBQT failure were randomly assigned to receive TBQT or LBQT for 14 days. All patients underwent endoscopy for culture-based antibiotic susceptibility testing. Patients in the TBQT group exhibiting levofloxacin susceptibility were randomized to receive amoxicillin, levofloxacin, esomeprazole, and colloidal bismuth pectin (ALEB) or amoxicillin, furazolidone, esomeprazole, and colloidal bismuth pectin (AFEB) for 14 days; patients with levofloxacin resistance received AFEB.

RESULTS

From May 2016 to June 2019, 364 subjects were enrolled. Eradication rates were significantly higher in the TBQT group (n = 182) than in the LBQT group (n = 182) according to both intention-to-treat (ITT) analysis (89.6% vs. 64.8%, P < 0.001) and per protocol (PP) analysis (91.1% vs. 67.8%, P < 0.001). Among patients in the TBQT group with levofloxacin susceptibility, eradication rates were similar in the ALEB (n = 51) and AFEB (n = 50) subgroups according to both the ITT (86.3% vs. 90.0%, P = 0.56) and PP (88.0% vs. 90.0%, P = 0.75) analyses. Isolated clarithromycin and levofloxacin resistance rates were 57.7% and 44.5%, respectively. The total clarithromycin and levofloxacin resistance rate in strains with dual or triple resistance was 35.7%.

CONCLUSIONS

TBQT was more effective than LBQT as a second-line strategy after CBQT failure. In the absence of antibiotic susceptibility testing, AFEB therapy might be used as a rescue therapy to eradicate H. pylori and avoid levofloxacin resistance.Trial registration: Chinese Clinical Trial Registry (www.chictr.org.cn): ChiCTR1900027743.

Bovine lactoferrin enhances the efficacy of levofloxacin-based triple therapy as first-line treatment of Helicobacter pylori infection: an in vitro and in vivo study

Objectives

To evaluate the in vitro antimicrobial/antivirulence action of bovine lactoferrin and its ability to synergize with levofloxacin against resistant Helicobacter pylori strains and to analyse the effect of levofloxacin, amoxicillin and esomeprazole with and without bovine lactoferrin as the first-line treatment for H. pylori infection.

Methods

The bovine lactoferrin antimicrobial/antivirulence effect was analysed in vitro by MIC/MBC determination and twitching motility against six clinical H. pylori strains and a reference strain. The synergism was evaluated using the chequerboard assay. The prospective therapeutic trial was carried out on two separate patient groups, one treated with esomeprazole/amoxicillin/levofloxacin and the other with esomeprazole/amoxicillin/levofloxacin/bovine lactoferrin. Treatment outcome was determined with the [¹³C]urea breath test.

Results

In vitro, bovine lactoferrin inhibited the growth of 50% of strains at 10 mg/mL and expressed 50% bactericidal effect at 40 mg/mL. The combination of levofloxacin and bovine lactoferrin displayed a synergistic effect for all strains, with the best MIC reduction of 16- and 32-fold for levofloxacin and bovine lactoferrin, respectively. Bovine lactoferrin at one-fourth MIC reduced microbial motility significantly for all strains studied. In the in vivo study, 6 of 24 patients recruited had treatment failure recorded with esomeprazole/amoxicillin/levofloxacin (75% success, 95% CI 57.68%–92.32%), and in the group with esomeprazole/amoxicillin/levofloxacin/bovine lactoferrin, 2 out of 53 patients recruited had failure recorded (96.07% success, 95% CI 90.62%–101.38%).

Conclusions

Bovine lactoferrin can be considered a novel potentiator for restoring susceptibility in resistant H. pylori strains. Bovine lactoferrin added to a triple therapy in first-line treatment potentiates the therapeutic effect.

Antibiotic resistance and clonal relatedness of Helicobacter pylori strains isolated from stomach biopsy specimens in northeast of Iran

BACKGROUND

Resistant Helicobacter pylori to commonly used antimicrobial agents are associated with severe upper gastrointestinal disorders. To provide an epidemiological picture of H pylori and characterize the resistance pattern and genetic variation of clinical isolates, stomach biopsies from patients with functional dyspepsia were evaluated in northeast of Iran.

MATERIALS AND METHODS

In this study, 80 patients were recruited. Finally, fifty H pylori strains were isolated from antrum and corpus biopsies by culturing on Columbia agar. All strains were identified by standard laboratory procedures. Susceptibility testing of antibiotics was performed using minimum inhibitory concentration test. Allele-specific primer (ASP)-PCR of 23S rRNA which associated with clarithromycin resistance was done among resistant strains. Moreover, cagA gene and polymorphism in vacA were detected. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was applied to investigate the genetic variations among all strains.

RESULTS

Antibiotic resistance pattern of H pylori strains was as follows: 68% (34/50) to metronidazole, 50% (25/50) to rifampicin, 30% (15/50) to amoxicillin, 28% (14/50) to levofloxacin, 22% (11/50) to clarithromycin, and 16% (8/50) to tetracycline. Multidrug-resistant strains were observed in 19 strains (38%). ASP-PCR of 23S rRNA showed four strains had A2143G mutation, six strains had A2142G mutation, and one strain had a Wt+A2143G mutation. Amplification of virulence-associated genes revealed that cagA was present in 27 isolates (54%) and vacA in 36 isolates (72%). The most common genotype of H pylori was vacA s1am2 (40%) followed by vacA s2m2 (14%), vacA s1am1 (12%), vacA s1bm1 (4%), and vacA s1bm2 (2%). DNA fingerprinting pattern indicated a high heterogeneity among isolated strains.

CONCLUSION

An alarming level of resistance to metronidazole and rifampicin and high heterogeneity among H pylori isolates highlighted the importance of continued monitoring of antimicrobial susceptibility and epidemiological surveillance of this pathogen.

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.

Pylera® plus ranitidine vs Pylera® plus esomeprazole in first-line treatment of Helicobacter pylori infection: Two pilot studies

BACKGROUND

Several studies have shown that Pylera^® (three-in-one capsules containing 140 mg bismuth potassium subcitrate, 125 metronidazole, and tetracycline 125 mg) in association with omeprazole or esomeprazole is a good option in the treatment of Helicobacter pylori infection. In particular, the adjunction of a PPI to Pylera^® may be useful to overcome metronidazole resistance. However, omeprazole and its derivatives can promote greater bismuth absorption and enhance its toxicity. The H2 receptor antagonist (H2RA) ranitidine seems to induce less bismuth absorption and as a consequence less systemic toxicity.

AIM

To evaluate whether Pylera^® in combination with esomeprazole or with ranitidine is equally effective in the treatment of H. pylori infection.

MATERIAL AND METHODS

Two separate groups of patients were treated simultaneously. One group was treated with Pylera^® three capsules qid plus esomeprazole 40 mg bid for 10 days (group A), and the other group was treated with Pylera^® three capsules qid plus ranitidine 300 mg bid for 10 days (group B). H. pylori eradication was defined as a negative result in ¹³ C urea breath test performed at least 8 weeks after the end of treatment with a delta-over-baseline value less than 5.

RESULTS

Thirty-two patients were recruited for group A and thirty-three patients in group B. Eradication rates were 93.7% (30/32) and 90.9% (30/33), respectively, at intention-to-treat analysis, and 96.6% (29/30) and 93.3% (28/30), respectively, at per-protocol analysis. Adverse events occurred in 26 patients and led to the suspension of treatment in one patient in group A and in one patient in group B.

CONCLUSION

The results showed that Pylera® plus a PPI or ranitidine were equally effective in the population studied. The high cure rates of bismuth triple therapy (without an antisecretory drug) and the lack of susceptibility testing make it impossible to exclude the possibility that the results would have been similar if neither the PPI nor the ranitidine were given.

Efficacy of tailored therapy for Helicobacter pylori eradication based on clarithromycin resistance and survey of previous antibiotic exposure: A single-center prospective pilot study

BACKGROUND

As the prevalence of antibiotic resistance is increasing, the effectiveness of traditional Helicobacter pylori (H pylori) therapies is gradually declining. We aimed to evaluate the efficacy of tailored therapy (dual priming oligonucleotide [DPO]-based multiplex PCR) and previous antibiotic exposure survey predicting for antibiotic resistance.

MATERIALS AND METHODS

Patients with H pylori infection who did not receive previous treatment were enrolled. The patients were divided into four groups (no resistance [NR] group, clarithromycin resistance [CLA-R] group, metronidazole-resistant [MET-R] group, and CLA- and MET-resistant [Dual-R] group) based on the results of dual priming oligonucleotide (DPO) polymerase chain reaction (PCR) and previous antibiotic exposure survey, and they were treated with tailored therapy based on antibiotic susceptibility.

RESULTS

Consecutive patients were distributed in the NR (n = 36, 70.6%), CLA-R (n = 9, 17.6%), and suspected MET-R (n = 6, 11.8%) group. The overall intention-to-treat/per-protocol eradication rate (ITT/PP) was 92.2%/94.0%. In the subgroup analysis, the ITT and PP of the NR, CLA-R, and MET-R groups were 94.4%/94.4%, 77.8%/87.5%, and 100.0%/100.0%, respectively. Total of 31 patients in all subgroups were evaluated for antibiotic resistance; five (16.1%), two (6.5%), and three (9.7%) participants showed CLA, MET, and dual resistance in culture-based susceptibility test. Compared with culture-based MIC test, the accuracy of DPO-based multiplex PCR in determining CLA resistance was 90.3%, while the accuracy of survey in determining MET resistance was only 77.4%.

CONCLUSION

A tailored therapy based on DPO-PCR and history of previous antibiotic use is useful in clinical practice and well correlated with culture-based susceptibility test.

Antibiotic dispensation rates among participants in community-driven health research projects in Arctic Canada

Background

Community-driven projects that aim to address public concerns about health risks from H. pylori infection in Indigenous Arctic communities (estimated H. pylori prevalence = 64%) show frequent failure of treatment to eliminate the bacterium. Among project participants, treatment effectiveness is reduced by antibiotic resistance of infecting H. pylori strains, which in turn, is associated with frequent exposure to antibiotics used to treat other infections. This analysis compares antibiotic dispensation rates in Canadian Arctic communities to rates in urban and rural populations in Alberta, a southern Canadian province.

Methods

Project staff collected antibiotic exposure histories for 297 participants enrolled during 2007–2012 in Aklavik, Tuktoyaktuk, and Fort McPherson in the Northwest Territories, and Old Crow, Yukon. Medical chart reviews collected data on systemic antibiotic dispensations for the 5-year period before enrolment for each participant. Antibiotic dispensation data for urban Edmonton, Alberta (average population ~ 860,000) and rural northern Alberta (average population ~ 450,000) during 2010–2013 were obtained from the Alberta Government Interactive Health Data Application.

Results

Antibiotic dispensation rates, estimated as dispensations/person-years (95% confidence interval) were: in Arctic communities, 0.89 (0.84, 0.94); in Edmonton, 0.55 (0.55, 0.56); in rural northern Alberta, 0.63 (0.62, 0.63). Antibiotic dispensation rates were higher in women and older age groups in all regions. In all regions, the highest dispensation rates occurred for β-lactam and macrolide antibiotic classes.

Conclusions

These results show more frequent antibiotic dispensation in Arctic communities relative to an urban and rural southern Canadian population.

Antimicrobial resistance of Helicobacter pylori in Germany, 2015 to 2018

OBJECTIVES

National and international guidelines recommend empiric first-line treatments of individuals infected with Helicobacter pylori without prior antimicrobial susceptibility testing. For this reason, knowledge of primary resistance to first-line antibiotics such as clarithromycin is essential. We assessed the primary resistance of H. pylori in Germany to key antibiotics by molecular genetic methods and evaluated risk factors for the development of resistance.

METHODS

Gastric tissue samples of 1851 yet treatment-naïve H. pylori-positive patients were examined with real-time PCR or PCR and Sanger sequencing for mutations conferring resistance to clarithromycin, levofloxacin and tetracycline. Clinical and epidemiological data were documented and univariable and multivariable logistic regression analyses were conducted.

RESULTS

Overall primary resistances were 11.3% (210/1851) to clarithromycin, and 13.4% (201/1497) to levofloxacin; resistance to tetracycline (2.5%, 38/1497) was as low as combined resistance to clarithromycin/levofloxacin (2.6%, 39/1497). Female sex and prior antimicrobial therapies owing to unrelated bacterial infections were risk factors for clarithromycin resistance (adjusted OR (aOR) 2.3, 95% CI 1.6-3.4; and 2.6, 95% CI 1.5-4.5, respectively); older age was associated with levofloxacin resistance (aOR for those ≥65 years compared with those 18-35 years: 6.6, 95% CI 3.1-14.2).

CONCLUSIONS

Clarithromycin might still be recommended in first-line eradication therapies in yet untreated patients, but as nearly every tenth patient may carry clarithromycin-resistant H. pylori it may be advisable to rule out resistance ahead of treatment by carrying out susceptibility testing or prescribing an alternative therapy.

Effect of Age on Effectiveness of Vonoprazan in Triple Therapy for Helicobacter pylori Eradication

Objective We evaluated the efficacy of vonoprazan-based eradication therapy for Helicobacter pylori (H. pylori), including the effects of age, gender, and grade of atrophy in comparison to proton pump inhibitor-based therapy. Method We retrospectively reviewed the records of 1,172 patients who received first-line triple therapy with amoxicillin, clarithromycin, and vonoprazan or a proton pump inhibitor (PPI) for H. pylori eradication, as well as 157 patients treated with second-line therapy consisting of amoxicillin, metronidazole, and vonoprazan or a PPI. Results The eradication rate of all cases treated with first-line triple therapy was 86.9% (1,019/1,172), while that in those treated with vonoprazan-based therapy was 92.5% (384/415). Our analysis showed that the use of vonoprazan resulted in a significantly improved success rate of first-line eradication therapy in comparison to proton pump inhibitor-based therapy [odds ratio (OR), 2.36; 95% confidence interval (CI) 1.55 to 3.56]. The superiority of vonoprazan was remarkable in non-elderly patients, while its effect was unclear in elderly patients. When used as second-line eradication therapy, the advantage of vonoprazan over PPI administration was not clear. Conclusion The inclusion of vonoprazan increased the success rate of first-line eradication therapy; however, the advantage was reduced with aging and remained unclear in elderly patients.

Pistacia vera L. oleoresin and levofloxacin is a synergistic combination against resistant Helicobacter pylori strains

The increasing multidrug resistance in Helicobacter pylori, also correlated to its biofilm-forming ability, underlines the need to search novel strategies to improve the eradication rate. Natural compounds are proposed as antibiotic-resistant-breakers capable to restore the efficacy of conventional drugs. Aim of this work was to evaluate the capability of Pistacia vera L. oleoresin (ORS) to synergize with levofloxacin (LVX) against resistant H. pylori strains. The antimicrobial activity of P. vera L. ORS and LVX and their combinations was determined by MIC/MBC (in neutral and acidic environments) and checkerboard tests. The anti-biofilm effect was determined by biomass quantification. In vivo Galleria mellonella model was used to confirm in vitro data. Pistacia vera L. ORS and LVX MICs ranged respectively from 780 to 3120 mg/l and from 0.12 to 2.00 mg/l, at pH 7.0 and 5.5. MBCs were similar to MICs. Pistacia vera L. ORS was able to synergize with LVX, restoring its effectiveness in LVX resistant strains. Pistacia vera L. ORS, LVX and their synergistic combinations displayed significant biofilm reduction. Pistacia vera L. ORS and LVX, showed protective effect against H. pylori infection on G. mellonella (62% and 63% of survival, respectively). Pistacia vera L. ORS can be considered a promising potentiator to restore the effectiveness of LVX tackling the H. pylori antibiotic resistance phenomenon.

High primary antibiotic resistance of Helicobacter Pylori strains isolated from dyspeptic patients: A prevalence cross-sectional study in Spain

BACKGROUND

The rate of H. pylori resistance to different antibiotics is increasing and determines the selection of eradication therapy. The aim of this study was to determine the resistance patterns of H. pylori strains in our area.

METHODS

Biopsies from gastric corpus for microbiological culture and antibiotic resistance were obtained in patients undergoing upper gastrointestinal endoscopy for dyspepsia. Selective Agar Pylori for isolation of the bacteria and Agar Mueller-Hinton supplemented with blood to test the sensitivity to antibiotics were used. Presence of H. pylori was confirmed using direct observation with phase-contrast microscopy and/or smears stained with acridine orange. In vitro bacterial susceptibility to amoxicillin, clarithromycin, rifampicin, tetracycline, metronidazole, and levofloxacin was tested using diffusion MIC test strips. Minimum inhibitory concentration values were determined based on the 6th version of the EUCAST (European Committee on Antimicrobial Susceptibility Testing) Clinical Breakpoint (2016).

RESULTS

Two hundred and seventeen patients were included (58.1% female, median age 64 years, range 25-92). H. pylori was identified in 108 patients (49.8%); culture and antibiogram were completed in 77 of them (71.3% of H. pylori-positive patients). The resistance rates were as follows: levofloxacin 38.7%, rifampicin 33.3%, metronidazole 27% and clarithromycin 22.4%. No case of amoxicillin or tetracycline resistance was identified. Dual clarithromycin-metronidazole resistance was observed in 10% of strains, whereas multiple drug-resistant was observed in 14.2%.

CONCLUSIONS

Resistance rate of H. pylori to antibiotics is high in the northwest of Spain. The high resistance to levofloxacin and clarithromycin advises against their wide empirical use of these antibiotics in eradication regimens.

Antibiotic susceptibility, heteroresistance, and updated treatment strategies in Helicobacter pylori infection

In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp) eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach) is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016) are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently approved in Japan, is also considered to be a promising solution for Hp eradication, even for clarithromycin-resistant strains. Furthermore, there is growing interest in finding new therapeutic strategies, such as the development of vaccines or the use of natural resources, including probiotics, plants, or nutraceuticals.

A Review on Antibiotic Resistance: Alarm Bells are Ringing

Antibiotics are the 'wonder drugs' to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged. The aim of this review is to explore the origin, development, and the current state of antibiotic resistance, regulation, and challenges by examining available literature. We found that antibiotic resistance is increasing at an alarming rate. A growing list of infections i.e., pneumonia, tuberculosis, and gonorrhea are becoming harder and at times impossible to treat while antibiotics are becoming less effective. Antibiotic-resistant infections correlate with the level of antibiotic consumption. Non-judicial use of antibiotics is mostly responsible for making the microbes resistant. The antibiotic treatment repertoire for existing or emerging hard-to-treat multidrug-resistant bacterial infections is limited, resulting in high morbidity and mortality report. This review article reiterates the optimal use of antimicrobial medicines in human and animal health to reduce antibiotic resistance. Evidence from the literature suggests that the knowledge regarding antibiotic resistance in the population is still scarce. Therefore, the need of educating patients and the public is essential to fight against the antimicrobial resistance battle.

[Molecular genetic predictors of resistance to anti-Helicobacter pylori therapy]

In current clinical practice, there is no optimal empirical therapy for Helicobacter pylori (H. pylori) infection and there is a progressive decrease in the efficiency of classical eradication therapy (ET) regimens. The variability in the efficiency of ET in a specific patient is largely due to the heterogeneous molecular genetic mechanisms underlying the resistance of the microorganism to the components of the treatment regimens. The basis of the mechanisms for antibiotic resistance in H. pylori is mainly the point mutations in some genes, which determine alterations in the mechanisms of action of drugs, such as clarithromycin (domain V of 23S rRNA), metronidazole (rdxA, frxA), amoxicillin (pbp1A), tetracycline (16S rRNA), and levofloxacin (gyrA). The predictors of resistance to ET are also the CagA-negative status of the microorganism and the presence of the vacA s2 allele. There are a number of host genetic determinants (the CYP2C19 genotype (*1/*1, *1/*17, *17/*17) and the MDR1 3435 T/T genotype (in an Asian population)) that reduce the efficiency of ET, by altering the pharmacokinetics of proton pump inhibitors. In addition, the IL-1β-511 C/C polymorphism that affects gastric acid secretion is a predictor of the inefficiency of ET.

Antibiotic Resistant Pattern of Helicobacter Pylori Infection Based on Molecular Tests in Laos

BACKGROUND

The efficacy of standard treatment of Helicobacter pylori (H. pylori) is declining because of antibiotic resistance. Clarithromycin resistance is also increasing in many Asian countries. The aim of this study was to determine the antibiotic susceptibility patterns of H. pylori infection and clinical association in Laos.

MATERIALS AND METHODS

A total of 329 Lao dyspeptic patients who underwent gastroscopy at Mahosot Hospital, Vientiane, Laos during December 2010-March 2012 were enrolled in this study. During gastroscopy, 4 biopsies were collected (2 each from the antrum and body) for CLO-test and histopathology. Only the positive CLO-test gastric tissues was stored at -80° in a freezer until DNA was extracted and a GenoType®HelicoDR test was conducted for detecting mutations in the rrl gene encoding 23S rRNA (clarithromycin resistance) and mutations in gyrA gene (fluoroquinolone resistance) .

RESULTS

Of the total, 119 Lao patients (36.2%) were infected with H. pylori including 59 males (49.6%) and 60 females (50.4%) with a mean age of 46 years. Clarithromycin and fluoroquinolone resistance of H. pylori infection was demonstrated in 15 (12.6%) and 16 strains (13.4%) respectively. In clarithromycin resistance, the number of patients who had education above primary school and BMI≥ 25 kg/m2 were significantly higher than those who had education below primary school and BMI< 25 kg/m2 (23.1% vs 7.5%, P-value= 0.036 and 20.5% vs 8%, P-value= 0.048, respectively). In fluoroquinolone resistance, the number of lowland Lao was significantly higher than those of non- lowland (highland and midland) Lao ethnic groups (16.7% vs 0%, P-value= 0.039).

CONCLUSIONS

H. pylori infections remain common in Laos. Clarithromycin and fluoroquinolone resistance with H. pylori infection are growing problems. Education above primary school and BMI ≥ 25 kg/m2 might be predictors for clarithromycin resistance and lowland Lao ethnicity might be predictors for fluoroquinolone resistance with H. pylori infection in Laos.

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.

Prevalence of Primary Antimicrobial Resistance of H. pylori in Turkey: A Systematic Review

BACKGROUND

The prevalence of clarithromycin resistance has increased to the 20% or more in different regions of the world. Clarithromycin resistance is known to be responsible for most of the treatment failures in Helicobacter pylori (H. pylori) infection. The aim of this systematic review was to summarize the prevalence of primary antibiotic resistance (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori strains in different geographical regions of Turkey.

MATERIAL AND METHODS

An Internet search was performed using PubMed and the ULAKBIM Turkish Medical Database. The terms "primary antibiotic resistance (separately; amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori" with and without "Turkey" or "different geographical regions of Turkey" were searched among articles published in both English and Turkish language within the time span from 1999 to 2015. Data analysis was performed using MedCalc 12.7.0. Each article was weighted according to the number of isolated H. pylori strains. Pooled proportion analysis was performed.

RESULTS

Twenty-one Turkish studies including 1059 H. pylori strains were included in this review. The overall primary antibiotic resistance rates of H. pylori strains isolated in Turkey were as follows: amoxicillin 3 (0.971%), clarithromycin 425 (24.864%), metronidazole 75 (33.747%), tetracycline 2 (3.511%), and levofloxacin 31 (23.769%).

CONCLUSIONS

Primary antibiotic resistance against H. pylori in Turkey shows differences between geographical regions and population densities. There is an increase in primary resistance rates to clarithromycin and metronidazole in different years. The data are not sufficient for tetracycline, amoxicillin, and levofloxacin. High clarithromycin resistance rates were mostly detected in overpopulated cities like Ankara (north), Izmir (west), Istanbul (west), and Bursa (west).

Low prevalence of clarithromycin-resistant Helicobacter pylori isolates with A2143G point mutation in the 23S rRNA gene in North India

Resistance of Helicobacter pylori to clarithromycin is associated with a single base substitution in the 23S rRNA gene. In this study, clarithromycin-resistant H. pylori isolates were analysed for the presence of 23S rRNA gene mutations. H. pylori were isolated from 68 patients suffering from various gastroduodenal diseases in North India. Minimum inhibitory concentrations (MICs) were determined by the agar dilution method, and point mutations in clarithromycin-resistant strains were identified by PCR-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. Clarithromycin resistance was observed in 11.8% (8/68) of the H. pylori isolates in North India. The A2143G point mutation in the 23S rRNA gene was found in 87.5% (7/8) of the clarithromycin-resistant strains, and the A2142G mutation in association with the T2182C mutation was found in 12.5% (1/8). In conclusion, the continued high prevalence of clarithromycin-sensitive H. pylori strains (88.2%) observed in this study allows the use of the triple-therapy regimen for the treatment of H. pylori infection in this region. Surveillance studies need to be conducted at regular intervals for clarithromycin resistance in the population. To our knowledge, this is the first study in India to report that point mutations at position A2143G and at A2142G in association with T2182C are associated with clarithromycin resistance, confirming reports from other parts of the world.

Review article: the global emergence of Helicobacter pylori antibiotic resistance

BACKGROUND

Helicobacter pylori is one of the most prevalent global pathogens and can lead to gastrointestinal disease including peptic ulcers, gastric marginal zone lymphoma and gastric carcinoma.

AIM

To review recent trends in H. pylori antibiotic resistance rates, and to discuss diagnostics and treatment paradigms.

METHODS

A PubMed literature search using the following keywords: Helicobacter pylori, antibiotic resistance, clarithromycin, levofloxacin, metronidazole, prevalence, susceptibility testing.

RESULTS

The prevalence of bacterial antibiotic resistance is regionally variable and appears to be markedly increasing with time in many countries. Concordantly, the antimicrobial eradication rate of H. pylori has been declining globally. In particular, clarithromycin resistance has been rapidly increasing in many countries over the past decade, with rates as high as approximately 30% in Japan and Italy, 50% in China and 40% in Turkey; whereas resistance rates are much lower in Sweden and Taiwan, at approximately 15%; there are limited data in the USA. Other antibiotics show similar trends, although less pronounced.

CONCLUSIONS

Since the choice of empiric therapies should be predicated on accurate information regarding antibiotic resistance rates, there is a critical need for determination of current rates at a local scale, and perhaps in individual patients. Such information would not only guide selection of appropriate empiric antibiotic therapy but also inform the development of better methods to identify H. pylori antibiotic resistance at diagnosis. Patient-specific tailoring of effective antibiotic treatment strategies may lead to reduced treatment failures and less antibiotic resistance.

A Triple and Quadruple Therapy with Doxycycline and Bismuth for First-Line Treatment of Helicobacter pylori Infection: A Pilot Study

BACKGROUND

Tetracycline-containing triple therapy has been suggested as an alternative first-line therapy for H. pylori infection.

AIM

To evaluate the effect of two dosages of doxycycline (DOX) associated with amoxicillin and esomeprazole with and without bismuth subcitrate as first-line treatment of H. pylori infection.

METHODS

Helicobacter pylori-positive patients underwent a 10-day therapy randomized into four groups: Group A received esomeprazole, amoxicillin, and DOX-100 mg b.i.d. (EAD-100), Group B a quadruple therapy with esomeprazole, amoxicillin, DOX-100 mg b.i.d. and bismuth subcitrate (EADB-100), Group C a triple therapy with esomeprazole, amoxicillin, and DOX-200 mg b.i.d. (EAD-200) and Group D a quadruple therapy with esomeprazole, amoxicillin, DOX-200 mg b.i.d., and bismuth subcitrate (EADB-200). Success was accessed by (13)C urea breath test 2 months after the end of treatment. The number of patients to be recruited for each group had to be at least 50 subjects. Treatment success of 80% or less was considered unacceptable. Stopping rules therefore were anytime six failures had occurred.

RESULTS

In the EAD-100 group and in EAD-200 group, the recruitment was stopped at the 14th and 15th patient, respectively. Fifty-two patients entered in the EADB-100 group and 51 in the EADB-200 group. Intention to treat eradication was in EADB-100 group 46/52 (88.5%, 95% CI 76.6-95.6); in the EADB-200 group 47/51 (92.1%, 95% CI: 81.1-97.8) (n.s.). Side effects were absent.

CONCLUSION

The adjunction of bismuth subcitrate to a triple therapy that includes esomeprazole, amoxicillin, and DOX in patients who are treated for the first time for the H. pylori infection potentiates the therapeutic effect. This regimen, however, deserves to be optimized in terms of duration and dose of DOX.

Antibiotic Resistance of Helicobacter pylori Among Male United States Veterans

BACKGROUND & AIMS

The most recent information published on resistance of Helicobacter pylori to antibiotics in a large population in the United States is more than 10 years old. We assessed the susceptibility of H pylori to antibiotics among patients in a large metropolitan hospital, as well as demographic, clinical, and lifestyle factors associated with antimicrobial resistance.

METHODS

We performed a cross-sectional study of a random sample of 656 patients (90.2% men) from a cohort of 1559 undergoing esophagogastroduodenoscopy with collection of gastric biopsies from 2009 through 2013 at the Houston Veterans Affairs Medical Center. We performed culture analyses of gastric tissues to detect H pylori. The minimum inhibitory concentrations of amoxicillin, clarithromycin, metronidazole, levofloxacin, and tetracycline were determined by the Epsilometer test. Logistic regression analysis was performed to estimate the association between risk factors and antimicrobial resistance.

RESULTS

Biopsies from 135 subjects (20.6%) tested positive for H pylori; 128 of these were from men (94.8%). Only 65 strains were susceptible to all 5 antibiotics. The prevalence of resistance to levofloxacin was 31.3% (95% confidence interval [CI], 23.1%-39.4%), to metronidazole it was 20.3% (95% CI, 13.2%-27.4%), to clarithromycin it was 16.4% (95% CI, 9.9%-22.9%), and to tetracycline it was 0.8% (95% CI, 0.0%-2.3%). No isolate was resistant to amoxicillin. Clarithromycin resistance increased from 9.1% in 2009-2010 to 24.2% in 2011-2013. In multivariate analysis, prior treatment of H pylori infection and use of fluoroquinolones were significantly associated with clarithromycin and levofloxacin resistance, respectively.

CONCLUSIONS

H pylori resistance to clarithromycin increased between 2009 and 2013; resistance to metronidazole remains high in infected men in the United States. The high frequency of resistance to levofloxacin is a new and concerning finding.

The Primary Resistance of Helicobacter pylori in Taiwan after the National Policy to Restrict Antibiotic Consumption and Its Relation to Virulence Factors-A Nationwide Study

Objective

The Taiwan Government issued a policy to restrict antimicrobial usage since 2001. We aimed to assess the changes in the antibiotic consumption and the primary resistance of H. pylori after this policy and the impact of virulence factors on resistance.

Methods

The defined daily dose (DDD) of antibiotics was analyzed using the Taiwan National Health Insurance (NHI) research database. H. pylori strains isolated from treatment naïve (N=1395) and failure from prior eradication therapies (N=360) from 9 hospitals between 2000 and 2012 were used for analysis. The minimum inhibitory concentration was determined by agar dilution test. Genotyping for CagA and VacA was determined by PCR method.

Results

The DDD per 1000 persons per day of macrolides reduced from 1.12 in 1997 to 0.19 in 2008, whereas that of fluoroquinolones increased from 0.12 in 1997 to 0.35 in 2008. The primary resistance of amoxicillin, clarithromycin, metronidazole, and tetracycline remained as low as 2.2%, 7.9%, 23.7%, and 1.9% respectively. However, the primary levofloxacin resistance rose from 4.9% in 2000–2007 to 8.3% in 2008–2010 and 13.4% in 2011–2012 (p=0.001). The primary resistance of metronidazole was higher in females than males (33.1% vs. 18.8%, p<0.001), which was probably attributed to the higher consumption of nitroimidazole. Neither CagA nor VacA was associated with antibiotic resistance.

Conclusions

The low primary clarithromycin and metronidazole resistance of H. pylori in Taiwan might be attributed to the reduced consumption of macrolides and nitroimidazole after the national policy to restrict antimicrobial usage. Yet, further strategies are needed to restrict the consumption of fluoroquinolones in the face of rising levofloxacin resistance.

Prospective multicentre study on antimicrobial resistance of Helicobacter pylori in Germany

OBJECTIVES

Antimicrobial resistance of Helicobacter pylori endangers the successful eradication of the bacteria. The aim of this prospective surveillance study (ResiNet) is to continuously keep antimicrobial resistance of H. pylori in Germany under surveillance and to identify risk factors for its development.

METHODS

From July 2001 until December 2012, we tested the antimicrobial susceptibility of H. pylori strains isolated from 1651 prospectively enrolled patients. We analysed clinical and epidemiological data and identified risk factors for the development of resistance.

RESULTS

Average primary resistances were 29.4% for metronidazole, 6.7% for clarithromycin and 3.1% for both antimicrobials. Prior unsuccessful eradication treatments, female sex and country or continent of origin were identified as independent risk factors for development of resistance.

CONCLUSIONS

H. pylori-positive patients without prior eradication therapy can be treated empirically; antimicrobial susceptibility testing is recommended in previously unsuccessfully treated patients and in patients who have received antimicrobial chemotherapies due to unrelated bacterial infections.

Prevalence of Helicobacter pylori in symptomatic patients and detection of clarithromycin resistance using melting curve analysis

Abstract.

BACKGROUND

Clarithromycin is often a component of combination therapies for Helicobacter pylori eradication; however, increases in resistance rates have decreased the success of the treatment.

OBJECTIVE

This study was designed to determine the prevalence of H pylori infection in symptomatic patients and to detect clarithromycin resistance rates using melting curve analysis.

METHODS

Patients scheduled for upper endoscopy at the Endoscopy Unit of the Department of Gastroenterology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey, were assessed for enrollment in the study. Two pairs of gastric biopsy specimens (antrum and corpus) were obtained from each study patient. Histopathologic examination, rapid urease test, culture, and polymerase chain reaction (PCR) of the specimens were used to identify H pylori infection. Clarithromycin resistance was detected using melting curve analysis.

RESULTS

Seventy-five patients (41 women, 34 men; mean [SD]age, 42.6 [14.5] years [range, 17-70 years]) were included in the study. Using histopathology and rapid urease test, H pylori was detected in 40 (53.3%) of the 75 specimens. H pylori was detected using PCR in 40 (53.3%) specimens and by culture in 10 (13.3%) specimens. The specificity and sensitivity of PCR and culture were interpreted by comparing them with the results of histopathologic examination and urease tests. The specificity and sensitivity of PCR were 68.6% and 72.5%, respectively, and the specificity and sensitivity of culture were 97.1% and 22.5%, respectively. Of the 40 isolates, 21 (52.5%) were susceptible to clarithromycin, 12 (30.0%) were resistant, and a mixed susceptibility pattern was detected in 7 (17.5%) specimens. H pylori isolates from 19 (79.2%) of the 24 patients who had formerly used clarithromycin showed clarithromycin resistance.

CONCLUSIONS

The prevalence of H pylori infection was 53.3% for the symptomatic patients in this study, and 47.5% of the isolates showed clarithromycin resistance using melting curve analysis. The PCR-based system used in this study was accurate for the detection of H pylori infection as well as clarithromycin susceptibility testing directly in biopsy specimens.

Trends of second-line eradication therapy for Helicobacter pylori in Japan: a multicenter study in the Tokyo metropolitan area

BACKGROUND

In Japan, the eradication rate of first-line therapy for Helicobacter pylori (H. pylori) with a proton pump inhibitor (PPI), amoxicillin (AMPC) and clarithromycin (CAM) has been decreasing because of a high prevalence of CAM resistance. A possible decrease of the eradication rate for second-line therapy with a PPI, AMPC and metronidazole (MNZ) is of concern. The aim of this study is to assess the trends in second-line eradication therapy for H. pylori in Japan.

MATERIALS AND METHODS

We accumulated data retrospectively on patients administered second-line eradication therapy for Helicobacter pylori with a PPI, AMPC, and MNZ for 1 week after failure of first-line eradication therapy with a PPI, AMPC and CAM at 15 facilities in the Tokyo metropolitan area in Japan from 2007 to 2011. Trends for second-line eradication rates in modified intention-to-treat (ITT) analyses were investigated. Second-line eradication rates were categorized by three PPIs (rabeprazole (RPZ), lansoprazole (LPZ) or omeprazole (OMZ)) and evaluated.

RESULTS

We accumulated data on 1373 patients. The overall second-line eradication rate was 92.4%. Second-line eradication rates in 2007, 2008, 2009, 2010 and 2011 were 97.7, 90.6, 94.5, 91.8 and 91.8%, respectively, with no significant trends revealed. Second-line eradication rates categorized by three PPIs for the entire 5-year period were 91.6, 93.4 and 92.4% (RPZ, LPZ and OPZ, respectively) with no significant differences among the three PPIs.

CONCLUSIONS

From 2007 to 2011, there were no significant trends in the second-line eradication rates and the rates remained consistently high. From the viewpoint of high prevalence of CAM resistance in Japan, triple therapy with PPI, AMPC and MNZ may be a better strategy for first-line therapy compared to triple therapy with PPI, AMPC and CAM.

Primary clarithromycin resistance to Helicobacter pylori: Is this the main reason for triple therapy failure?

Conventional triple therapies for Helicobacter pylori (H. pylori) eradication have recently shown a disappointing reduction in effectiveness in many countries. The main reason for failure was found to be bacterial resistance to one of the most commonly used antibiotics, clarithromycin. An additional problem for conventional triple therapy is the high rate of resistance to metronidazole found in Europe, America and Asia. In Italy, in the last 15 years a 2-fold increase in resistance has occurred. A recent study of the whole of Italy included about 20 patients from each region at the first endoscopic diagnosis of H. pylori infection. The most surprising result was the patchy distribution of resistance, which was almost absent in two regions (one northern and one southern), although the highest prevalence was found in some regions of the South. In the paediatric population we found a 25% prevalence of resistance in a sample of H. pylori positive children observed between 2002 and 2007, mirroring data obtained in southern European countries. Clarithromycin resistance assessment is currently based on phenotypic detection performed after culture the agar dilution method or E-test, and genotypic methods based on polymerase chain reaction (PCR). In a recent comparative study we found a 71.2% agreement between the two methods. Culture-free techniques are highly accurate in finding even minimal traces of genotypically resistant strains. Moreover, PCR-based tools are accurate in detecting a heteroresistant status, defined as the co-existence of some strains that are susceptible and some resistant to the same antibiotic in an individual patient. Three point mutations, namely A2143G, A2142G and A2142C, are responsible for 90% of cases of primary clarithromycin resistance in H. pylori strains isolated in Western countries, although we previously demonstrated that the presence of the A2143G mutation, but not A2142G or A2142C, significantly lowered the H. pylori eradication rate. Treatment failure has considerable cost/benefit implications because of “waste” of National Health System and patient resources, in terms of drugs, further diagnostic tests and medical examination expenses. Therefore, in future it would be very useful to be able to test for clarithromycin resistance before starting conventional triple therapy. Hopefully, fast, effective non-invasive tests may soon be devised to determine this condition.

Antibiotic resistance of Helicobacter pylori isolated in the Southeast Coastal Region of China

BACKGROUND

The resistance of Helicobacter pylori (H. pylori) to antibiotics is increasing worldwide, lowering its efficacy in current eradication therapies. This study evaluated H. pylori resistance to antibiotics in the southeast coastal region of China and suggests appropriate alternatives.

MATERIALS AND METHODS

Seventeen thousand seven hundred and thirty one H. pylori strains were collected from eight areas of two provinces in coastal southeast China from 2010 to 2012. The resistance of these strains to six antibiotics was tested using the agar dilution method.

RESULTS

The resistance rates to clarithromycin, metronidazole, levofloxacin, amoxicillin, gentamicin and furazolidone were 21.5, 95.4, 20.6, 0.1, 0.1 and 0.1%, respectively. Double, triple and quadruple antibacterial resistant percentages were 25.5, 7.5 and 0.1%, respectively. A positive association between the resistance to levofloxacin and to clarithromycin was found, but there was a negative correlation in the resistances to levofloxacin and to metronidazole.

CONCLUSIONS

The prevalence of H. pylori resistance to clarithromycin, metronidazole, levofloxacin and multiple antibiotics in coastal southeast China is high. Choice of therapy should be individualized based on a susceptibility test in this region of the country.

Levofloxacin-containing triple and sequential therapy or standard sequential therapy as the first line treatment for Helicobacter pylori eradication in China

AIMS

To compare the efficacy and the adverse effects of levofloxacin-containing triple therapy, standard sequential therapy, and levofloxacin-containing sequential therapy as first-line treatment for Helicobacter pylori eradication.

METHODS

Three hundred and forty-five naive H. pylori-positive patients were randomized to receive levofloxacin-containing 7-day triple therapy (Levo triple, i.e., esomeprazole, 20 mg, twice daily, amoxicillin, 1 g, twice daily, and levofloxacin, 500 mg, once daily for 7 days, n = 114), standard sequential therapy (SST-10, 5-day esomeprazole, 20 mg, twice daily and amoxicillin, 1 g, twice daily followed by 5-day esomeprazole, 20 mg, twice daily, clarithromycin, 500 mg, twice daily and tinidazole, 500 mg, twice daily for 5 days, n = 115) or levofloxacin-containing sequential therapy (Levo-ST-10, 5-day esomeprazole, 20 mg, twice daily and amoxicillin, 1 g, twice daily for 5 days followed by 5-day esomeprazole, 20 mg, twice daily, levofloxacin, 500 mg, once daily and tinidazole, 500 mg, twice daily, n = 116). Eradication was confirmed by a (13) C-urea breath test 4 weeks after completion of treatment.

RESULTS

Intention to treat (ITT) eradication rates were 78.1% (95% CI: 69.4, 85.3%), 78.3% (95% CI: 69.6, 85.4%), and 82.8% (95% CI: 74.6, 89.1%) for Levo triple, SST-10, Levo-ST-10, respectively (p = .599). Per protocol (PP) eradication rates were 80.9% (95% CI: 72.3, 87.8%), 82.6% (95% CI: 74.1, 89.2%), and 86.5% (95% CI: 78.7, 92.2%), respectively, for the three therapies (p = .513). Overall, 3.8% experienced mild to moderate adverse events; the rates were 1.75, 4.35, and 5.17%, respectively, in the three groups (p = .325).

CONCLUSIONS

Standard sequential therapy and 7-day levofloxacin triple therapy produced unacceptably therapeutic efficacy in China. Only levofloxacin-containing sequential therapy achieved borderline acceptable result. None of the regimens tested reliably achieved 90% or greater therapeutic efficacy in China.

Quadruple therapy with moxifloxacin and bismuth for first-line treatment of Helicobacter pylori

AIM: To compare triple therapy vs quadruple therapy for 10 d as first-line treatment of Helicobacter pylori (H. pylori) infection.

METHODS: Consecutive H. pylori positive patients never treated in the past for this infection were randomly treated with triple therapy of pantoprazole (PAN) 20 mg bid, amoxicillin (AMO) 1 g bid and moxifloxacin (MOX) 400 mg bid for 10 d (PAM) or with quadruple therapy of PAN 20 mg bid, AMO 1 g bid, MOX 400 mg bid and bismuth subcitrate 240 mg bid for 10 d (PAMB). All patients were found positive at 13 C-Urea breath test (UBT) performed within ten days prior to the start of the study. A successful outcome was confirmed with an UBT performed 8 wk after the end of treatment. χ² analysis was used for statistical comparison. Per protocol (PP) and intention-to-treat (ITT) values were also calculated.

RESULTS: Fifty-seven patients were enrolled in the PAM group and 50 in the PAMB group. One patient in each group did not return for further assessment. Eradication was higher in the PAMB group (negative: 46 and positive: 3) vs the PAM group (negative: 44 and positive: 12). The H. pylori eradication rate was statistically significantly higher in the PAMB group vs the PAM group, both with the PP and ITT analyses (PP: PAMB 93.8%, PAM 78.5%, P < 0.02; ITT: PAMB 92%, PAM 77.1 %, P <0.03).

CONCLUSION: The addition of bismuth subcitrate can be considered a valuable adjuvant to triple therapy in those areas where H. pylori shows a high resistance to fluoroquinolones.

Helicobacter pylori Eradication Therapy: Current Availabilities

Background. Though Helicobacter pylori (HP) infections have progressively declined throughout most of the industrialized countries, a gradual increase in failure of HP eradication treatments is observed. Aim. To critically review evidence on the efficacy of the therapeutic availabilities for HP eradication, as yet. Methods. A selection of Clinical Trials, Systematic Reviews and Meta-analyses within the time period 2010–2012, was performed through a Medline search. Previous references were included when basically supporting the first selection. Results. An increasing rise in HP resistance rates for antimicrobial agents is currently observed. Further causes of HP treatment failure include polymorphisms of the CYP 2C19, an increased body mass index (BMI), smoking, poor compliance and re-infections. Alternative recent approaches to standard triple therapy have been attempted to increase the eradication rate, including bismuth-containing quadruple therapy, non-bismuth containing quadruple therapy, sequential therapy and levofloxacin-containing regimens. Conclusions. The main current aims should be the maintenance of a high eradication rate (>85%) of HP and the prevention of any increase in antimicrobial resistance. In the next future, the perspective of a tailored therapy could optimize eradication regimens within the different countries.

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.

Update on non-bismuth quadruple (concomitant) therapy for eradication of Helicobacter pylori

BACKGROUND

Traditional standard triple therapy for Helicobacter pylori (H. pylori) infection (proton pump inhibitor-clarithromycin-amoxicillin) can easily be converted to non-bismuth quadruple (concomitant) therapy by the addition of a nitroimidazole twice daily.

AIM

To critically review evidence on the role of non-bismuth quadruple therapy (proton pump inhibitor-clarithromycin-amoxicillin-nitroimidazole) in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE and relevant congresses up to December 2011. We performed a meta-analysis of the studies evaluating the concomitant therapy, and of the randomized controlled trials comparing the concomitant and the standard triple therapy.

RESULTS

A meta-analysis of 19 studies (2070 patients) revealed a mean H. pylori cure rate (intention-to-treat) of 88% (95% confidence interval from 85% to 91%) for non-bismuth quadruple therapy. We performed a meta-analysis of the randomized controlled studies comparing the concomitant (481 patients) and the standard triple therapy (503 patients). The former was more effective than the latter: 90% versus 78% (intention-to-treat analysis). Results were homogeneous (I(2) = 0%). The odds ratio for this comparison was 2.36 (95% confidence interval from 1.67 to 3.34). A tendency toward better results with longer treatments (7-10 days versus 3-5 days) has been observed, so it seems reasonable to recommend the length of treatment achieving the highest cure rates (10 days). Clarithromycin resistance may reduce the efficacy of non-bismuth quadruple therapy, although the decrease in eradication rates seems to be far lower than in standard triple therapy. Experience with the non-bismuth quadruple therapy in patients with metronidazole-resistant strains is still very limited.

CONCLUSION

Non-bismuth quadruple (concomitant) therapy appears to be an effective, safe, and well-tolerated alternative to triple therapy and is less complex than sequential therapy. Therefore, this regimen appears well suited for use in settings where the efficacy of triple therapy is unacceptably low.

Review article: the effectiveness of standard triple therapy for Helicobacter pylori has not changed over the last decade, but it is not good enough

BACKGROUND  A decrease in the Helicobacter pylori eradication rate after standard triple therapy has been suggested in recent years. AIM  To assess the efficacy of standard triple therapy in the eradication of H. pylori through an epidemiological analysis of all published Spanish trials. A secondary aim was to review the prevalence of clarithromycin resistance in Spain. METHODS  Articles on H. pylori eradication in Spain published in peer-reviewed journals were identified through MEDLINE searches. Studies that included a triple therapy consisting of any proton pump inhibitor with clarithromycin (500 mg b.d.) and amoxicillin (1 g b.d.) for up to 14 days were selected. Spanish studies evaluating the prevalence of clarithromycin resistance were also reviewed. Meta-analysis was performed using the generic inverse variance method. RESULTS The pooled eradication rates by year from Spanish studies evaluating the efficacy of the standard triple regimen revealed a relatively constant rate over the years. Overall, the analysis of the 32 studies (4727 patients) showed a mean H. pylori cure rate of 80% (95% CI = 77-82%) by intention-to-treat and 83% (81-86%) by per-protocol. When only peptic ulcer disease or 7-day regimens were considered, results were similar. Based on 13 studies (3293 patients), mean clarithromycin resistance rate was 8% (5-10%). CONCLUSION Although a decrease in the H. pylori eradication rate after triple therapy has been suggested in recent years, cure rates with this regimen did not change in Spain between 1997 and 2008. However, this by no means indicates that the efficacy of standard triple therapy in Spain is acceptable, as it has been calculated to be around only 80%. Therefore, it is evident that new strategies to improve first-line treatment are urgently needed.

Treatment of Helicobacter pylori

PURPOSE OF REVIEW

The article will give an overview on reasons for treatment failure and tries to show new concepts for Helicobacter pylori treatment.

RECENT FINDINGS

Several new treatment options or modifications of already established regimens have been introduced to overcome treatment failure. Antibiotic resistance to H. pylori is the key factor for treatment failure. At the moment, standard triple therapy remains the primary choice in regions with proven low clarithromycin resistance rates. In areas with high clarithromycin resistance, four drug treatment regimens, including quadruple and sequential therapy, have proven the best results as first-line regimens. The options for second-line treatment regimens are manifold. Second-line treatment regimens need to be adapted accurately to local resistance rates.

SUMMARY

Treatment of H. pylori infection is challenged by a dramatic fall in eradication rates all over the world. Newer regimens have been introduced including sequential, quadruple therapies and those regimens provide promising results, but the knowledge about local resistance rates remains the key to an effective therapy.

Review article: non-bismuth quadruple (concomitant) therapy for eradication of Helicobater pylori

BACKGROUND

Traditional standard triple therapy for Helicobacter pylori infection (PPI-clarithromycin-amoxicillin) can easily be converted to non-bismuth quadruple (concomitant) therapy by the addition of a nitroimidazole twice daily.

AIM

To critically review evidence on the role of non-bismuth quadruple therapy (PPI-clarithromycin-amoxicillin-nitroimidazole) in the treatment of H. pylori infection.

METHODS

Bibliographical searches were performed in MEDLINE and relevant congresses.

RESULTS

The first randomised comparison of the non-bismuth quadruple therapy and the sequential (PPI-amoxicillin 5days plus PPI-clarithromycin-nitroimidazole 5days) regimens recently concluded that both were similar in terms of efficacy and safety and that the sequential administration protocol may be unnecessarily complex. Several randomised controlled trials (and one meta-analysis) have demonstrated that non-bismuth quadruple therapy is more effective than and is equally well tolerated as standard triple therapy. A meta-analysis of 15 studies (1723 patients) revealed a mean H. pylori cure rate (intention-to-treat) of 90% for non-bismuth quadruple therapy. A tendency towards better results with longer treatments (7-10days vs. 3-5days) has been observed, so it seems reasonable to recommend the length of treatment by achieving maximal cure rates (10days). Clarithromycin resistance may reduce the efficacy of non-bismuth quadruple therapy, although the decrease in eradication rates seems to be far lower than in standard triple therapy. Experience with the non-bismuth quadruple therapy in patients with metronidazole-resistant strains is still very limited.

CONCLUSIONS

Non-bismuth quadruple (concomitant) therapy appears to be an effective, safe, and well-tolerated alternative to triple therapy and is less complex than sequential therapy. Therefore, this regimen appears well suited for use in settings where the efficacy of triple therapy is unacceptably low.

High Helicobacter pylori resistance to metronidazole but zero or low resistance to clarithromycin, levofloxacin, and other antibiotics in Malaysia

OBJECTIVE

Bacterial resistance to antibiotics is the single most important determinant of treatment success. The objective of this study was to determine the prevalence of Helicobacter pylori resistance to clarithromycin, amoxicillin, metronidazole, tetracycline, levofloxacin, rifabutin, and furazolidone in our local bacterial strains.

METHODS

Samples from consecutive ninety patients were obtained for culture and sensitivity testing. Resistance to individual antibiotics were tested using the E-test and MIC(90) read from the strips. Resistance to rifampicin and nitrofurantoin were used as a surrogate for rifabutin and furazolidine.

RESULTS

There was a high prevalence of resistance to metronidazole 68/90 (75.5%). No male (34/45 (75.5%) versus female (35/45 (77.7%) difference in frequency of metronidazole resistance was noted (p = 1.000). There was zero resistance (0) to clarithromycin, levofloxacin, amoxicillin, and nitrofurantoin/furazolidone. Resistance to rifampicin/rifabutin was for breakpoints of 1 and 4 μg/mL of 14.4 and 2.2% respectively.

CONCLUSIONS

Although there was high bacterial resistance to metronidazole, the absence of resistance particularly to the key antibiotics used in H. pylori eradication therapy: clarithromycin and levofloxacin is reassuring to note. Continued monitoring of antibiotic resistance should be carried out.