Usefulness of antimicrobial susceptibility in the eradication of Helicobacter pylori

The use of real-world evidence to generate cost analysis of antibiotic susceptibility testing (AST) in patients with Helicobacter pylori treatment failure in Thailand: A large population-based study

Background

H. pylori eradication is effective for gastric cancer prevention. Treatment failure is caused by increased antibiotic resistance. This study aimed to determine eradication rates and perform cost analysis between susceptibility-guided therapy and empirical treatment in patients with H. pylori treatment failure.

Methods

This retrospective cohort study included patients with dyspepsia undergoing gastroscopy at tertiary care center in Thailand from March 2014 to October 2021. Treatment failure was defined as persistent H. pylori infection after ≥1 regimen completion. Early AST was defined as AST performed shortly after first-line treatment failure. Demographic data, AST results, eradication regimens, and medication costs were collected from database and reviewed.

Results

Of 1080 patients with H. pylori infection, 315 had treatment failure (mean age 58.4 years; 44.4 % males). AST of 85 strains demonstrated resistance to levofloxacin (57.6 %), metronidazole (51.8 %), clarithromycin (44.7 %), and amoxicillin (4.7 %). In multivariate analysis, sequential therapy was significantly associated with treatment failure (OR 1.66; 95%CI 1.01-2.74, p = 0.045), whereas vonoprazan-containing therapy was related to treatment success (OR 1.60; 95%CI 1.04-2.48, p = 0.034). Medication nonadherence (OR 37.97; 95%CI 8.97-160.65, p < 0.001) contributed to treatment failure. Susceptibility-guided therapy provided better eradication rate than empirical therapy (97.5% vs. 65.5 %, OR 20.54; 95%CI 4.92-85.81, p < 0.001) in treatment failure group. Twenty-four patients had early AST, while 61 had AST after treatment failures. Most patients with early AST achieved treatment success by second-line eradication. Early AST provided significantly lower total average cost of treatment than group without AST ($368.2 vs. $402.0 per patient, p = 0.034) and AST after treatment failures ($368.2 vs. $752.8 per patient, p < 0.001). Early AST group had the lowest cost of subsequent medication, posttreatment urea breath test, and hospital visits.

Conclusion

Susceptibility-guided therapy provided significantly higher eradication rate than empirical therapy in patients with treatment failure. Early AST might be a cost-effective strategy for H. pylori eradication after failed therapy and can prevent unnecessary antibiotic use in Thailand.

Surveillance of Helicobacter pylori resistance over 22 Years (2000-2021) in Northern Spain

OBJECTIVES

Helicobacter pylori gastritis is considered an infectious disease, regardless of symptoms and stage of disease. Most consensus documents recommend empirical therapy based on local antimicrobial susceptibility patterns. We aimed to provide clinically useful information about primary and secondary antimicrobial resistance to antimicrobials commonly prescribed for H. pylori.

METHODS

Overall, 31,406 gastroduodenal biopsies and 2,641 string tests from patients over 15 years of age were plated on selective media, isolating H. pylori in 36.7% of biopsies and 50.7% of string tests. Susceptibility testing could be performed in 96.6% (12,399/12,835) of H. pylori isolates. Polymerase chain reaction (PCR) was also used to detect H. pylori and its resistance to clarithromycin, providing susceptibility data for 112 patients with negative culture results.

RESULTS

Resistance to amoxicillin and tetracycline was unusual (0.6% and 0.2%, respectively). Rates of primary resistance to clarithromycin and metronidazole remained steady over the 22-year study period, at around 14% for clarithromycin and 30% for metronidazole, while primary resistance to levofloxacin tripled (from 7.6% in 2000 to 21.7% in 2021, P < 0.001) and increased with patient age. Notably, 1.8% of isolates were multiresistant to clarithromycin, metronidazole, and levofloxacin. Overall, secondary resistance rates were higher (P < 0.0001) than primary resistance rates for clarithromycin (42.5% vs 14.1%), metronidazole (40.9% vs 32%), and levofloxacin (21.5% vs 17.1%).

CONCLUSION

Determination of susceptibility for H. pylori by culture and/or PCR in patients undergoing endoscopy could facilitate the implementation of tailored therapy and guide the choice of empirical therapy when susceptibility testing cannot be performed, potentially helping limit the emergence of antimicrobial resistance.

Helicobacter pylori Diagnostic Tests Used in Europe: Results of over 34,000 Patients from the European Registry on Helicobacter pylori Management

BACKGROUND AND AIMS

Several methods are available to diagnose Helicobacter pylori infection. Our objective was to evaluate the tests used for both the initial diagnosis and the confirmation of eradication after treatment in Europe.

METHODS

The European Registry on the management of Helicobacter pylori infection is an international, multicentre, prospective, non-interventional registry aiming to evaluate the management of Helicobacter pylori-infected patients in Europe. Countries with at least 100 cases registered from June 2013 to April 2021, and with a validated diagnostic method were analysed. Data were quality reviewed.

RESULTS

A total of 34,920 adult patients from 20 countries were included (mean age 51 years; 61% women). To establish the initial diagnosis, invasive tests were performed in 19,801 (71%) patients, non-invasive in 11,369 (41%), and both in 3437 (12%). The most frequent were histology (n = 11,885; 43%), a rapid urease test (n = 10,636; 38%) and an urea breath test (n = 7577; 27%). According to the age, invasive tests were indicated in 11,179 (77%) ≥50 years, and in 8603 (65%) <50 years. Depending on the country, the use of invasive tests ranged from 29-99% in <50 years to 60-99% in ≥50. Most of the tests used to confirm eradication were non-invasive (n = 32,540; 93%), with the urea breath test being the most frequent (n = 32,540; 78%). In 2983 (9%) post-treatment tests, histology (n = 1887; 5%) or a rapid urease test (n = 1223; 4%) were performed.

CONCLUSION

A great heterogeneity was observed for the initial diagnosis and confirmation of the eradication. The reasons for the apparent lack of adherence to the clinical guidelines should be further explored.

Helicobacter pylori Diagnostic Tests Used in Europe: Results of over 34,000 Patients from the European Registry on Helicobacter pylori Management

Background and aims: Several methods are available to diagnose Helicobacter pylori infection. Our objective was to evaluate the tests used for both the initial diagnosis and the confirmation of eradication after treatment in Europe. Methods: The European Registry on the management of Helicobacter pylori infection is an international, multicentre, prospective, non-interventional registry aiming to evaluate the management of Helicobacter pylori-infected patients in Europe. Countries with at least 100 cases registered from June 2013 to April 2021, and with a validated diagnostic method were analysed. Data were quality reviewed. Results: A total of 34,920 adult patients from 20 countries were included (mean age 51 years; 61% women). To establish the initial diagnosis, invasive tests were performed in 19,801 (71%) patients, non-invasive in 11,369 (41%), and both in 3437 (12%). The most frequent were histology (n = 11,885; 43%), a rapid urease test (n = 10,636; 38%) and an urea breath test (n = 7577; 27%). According to the age, invasive tests were indicated in 11,179 (77%) ≥50 years, and in 8603 (65%) <50 years. Depending on the country, the use of invasive tests ranged from 29–99% in <50 years to 60–99% in ≥50. Most of the tests used to confirm eradication were non-invasive (n = 32,540; 93%), with the urea breath test being the most frequent (n = 32,540; 78%). In 2983 (9%) post-treatment tests, histology (n = 1887; 5%) or a rapid urease test (n = 1223; 4%) were performed. Conclusion: A great heterogeneity was observed for the initial diagnosis and confirmation of the eradication. The reasons for the apparent lack of adherence to the clinical guidelines should be further explored.

Rates of Antimicrobial Resistance in Helicobacter pylori Isolates From Clinical Trial Patients Across the US and Europe

INTRODUCTION

Guidelines recommend that proton pump inhibitor-based triple regimens with clarithromycin not be used for Helicobacter pylori infection in areas where clarithromycin resistance is ≥15%, or in patients with prior macrolide use. Up-to-date information on local resistance patterns is limited, especially in the US. Here, we report resistance rates to antibiotics commonly used to treat H. pylori from a large study conducted in the US and Europe (pHalcon-HP).

METHODS

Gastric mucosal biopsies were collected from adult participants with H. pylori infection during screening. Minimum inhibitory concentrations were determined via agar dilution for clarithromycin, amoxicillin, and metronidazole, with breakpoints ≥1 μg/mL, >0.125 μg/mL, and >8 μg/mL, respectively. Resistance rates were obtained for the US and Europe, and also for US subregions and participating European countries.

RESULTS

Resistance rates were established in isolates from 907 participants. Overall, 22.2% were resistant to clarithromycin, 1.2% to amoxicillin, and 69.2% to metronidazole. Resistance in the US and Europe was similar; metronidazole resistance was the most prevalent (50%-79%) and amoxicillin the least (≤5%). In all subregions, ≥15% of isolates were resistant to clarithromycin, except the UK (0/8 isolates). Among clarithromycin-resistant isolates, 75% were also metronidazole-resistant. Two US isolates were resistant to clarithromycin and amoxicillin; one of these was also metronidazole-resistant.

DISCUSSION

The resistance rates observed in this study argue against the continued empiric use of proton pump inhibitor-based triple therapy containing clarithromycin, per treatment guidelines, and highlight the need for antibiotic resistance surveillance and novel treatment strategies for H. pylori infection in the US and Europe.

Empirical vs. Susceptibility-Guided Treatment of Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background

Treating Helicobacter pylori infection according to antibiotic resistance has been frequently recommended. However, information on its real effectiveness is scarce.

Aim

The aim of this study is to perform a meta-analysis comparing empirical vs. susceptibility-guided treatment of H. pylori.

Methods

Selection of studies: Studies comparing empirical versus susceptibility-guided treatment were selected. Search strategy: electronic and manual up to August 2021. Data synthesis: by intention-to-treat (random-effects model).

Results

Overall, 54 studies were included (6,705 patients in the susceptibility-guided group and 7,895 in the empirical group). H. pylori eradication rate was 86 vs. 76%, respectively (RR: 1.12; 95% CI: 1.08-1.17; I 2: 83%). Similar results were found when only RCTs were evaluated (24 studies; RR: 1.16; 95% CI: 1.11-1.22; I 2: 71%) and when susceptibility testing was assessed by culture (RR: 1.12; 95% CI: 1.06-1.18) or PCR (RR: 1.14; 95% CI: 1.05-1.23). For first-line treatments (naïve patients; 30 studies), better efficacy results were obtained with the susceptibility-guided strategy (RR: 1.15; 95% CI: 1.11-1.20; I 2: 79%). However, for empirical first-line quadruple regimens, in particular (both with and without bismuth, excluding the suboptimal triple therapies), not based on CYP2C19 gene polymorphism, no differences in efficacy were found compared with the susceptibility-guided group (RR: 1.04; 95% CI: 0.99-1.09); this lack of difference was confirmed in RCTs (RR: 1.05; 95% CI: 0.99-1.12). For rescue therapies (13 studies, most 2nd-line), similar results were demonstrated for both strategies, including all studies (RR: 1.09; 95% CI: 0.97-1.22; I 2: 82%) and when only RCTs were considered (RR: 1.15; 95% CI: 0.97-1.36).

Conclusion

The benefit of susceptibility-guided treatment over empirical treatment of H. pylori infection could not be demonstrated, either in first-line (if the most updated quadruple regimens are prescribed) or in rescue therapies.

A Culture-Based Strategy Is More Cost Effective Than an Empiric Therapy Strategy in Managing Pediatric Helicobacter pylori Infection

BACKGROUND

Helicobacter pylori infection is a major cause of peptic ulcers and gastric cancer. This study aimed to compare the eradication rate and essential costs of culture-based and empiric therapy strategies in treating pediatric H. pylori infection.

METHODS

We retrospectively enrolled patients aged <18 years with a diagnosis of H. pylori infection who received esophagogastroduodenoscopy at two medical centers in southern Taiwan from 1998 to 2018. Patients with positive cultures and minimum inhibitory concentration test results were allocated to a culture-based strategy, and those with negative cultures or without culture as an empiric therapy strategy. We collected demographic data and eradication rates, and calculated the total essential costs of treating a hypothetical cohort of 1,000 pediatric patients based on the two strategies.

RESULTS

Ninety-six patients were enrolled, of whom 55 received a culture-based strategy and 41 received an empiric therapy strategy. The eradication rates with the first treatment were 89.1 and 75.6% in the culture-based and empiric therapy strategy, respectively. There were no significant differences in age, sex, and endoscopic diagnosis between the two strategies. For every 10% increase in those receiving a culture-based strategy, the total cost would have been reduced by US$466 in a hypothetical cohort of 1,000 patients. For every 10% increase in successful eradication rate, the total cost was reduced by US$24,058 with a culture-based strategy and by US$20,241 with an empiric therapy strategy.

CONCLUSIONS

A culture-based strategy was more cost effective than an empiric therapy strategy in treating pediatric H. pylori-infected patients.

Antibiotic Resistance Prevalence and Trends in Patients Infected with Helicobacter pylori in the Period 2013-2020: Results of the European Registry on H. pylori Management (Hp-EuReg)

Background: Bacterial antibiotic resistance changes over time depending on multiple factors; therefore, it is essential to monitor the susceptibility trends to reduce the resistance impact on the effectiveness of various treatments. Objective: To conduct a time-trend analysis of Helicobacter pylori resistance to antibiotics in Europe. Methods: The international prospective European Registry on Helicobacter pylori Management (Hp-EuReg) collected data on all infected adult patients diagnosed with culture and antimicrobial susceptibility testing positive results that were registered at AEG-REDCap e-CRF until December 2020. Results: Overall, 41,562 patients were included in the Hp-EuReg. Culture and antimicrobial susceptibility testing were performed on gastric biopsies of 3974 (9.5%) patients, of whom 2852 (7%) were naive cases included for analysis. The number of positive cultures decreased by 35% from the period 2013-2016 to 2017-2020. Concerning naïve patients, no antibiotic resistance was found in 48% of the cases. The most frequent resistances were reported against metronidazole (30%), clarithromycin (25%), and levofloxacin (20%), whereas resistances to tetracycline and amoxicillin were below 1%. Dual and triple resistances were found in 13% and 6% of the cases, respectively. A decrease (p < 0.001) in the metronidazole resistance rate was observed between the 2013-2016 (33%) and 2017-2020 (24%) periods. Conclusion: Culture and antimicrobial susceptibility testing for Helicobacter pylori are scarcely performed (<10%) in Europe. In naïve patients, Helicobacter pylori resistance to clarithromycin remained above 15% throughout the period 2013-2020 and resistance to levofloxacin, as well as dual or triple resistances, were high. A progressive decrease in metronidazole resistance was observed.

Treatment Approach of Refractory Helicobacter pylori Infection: A Comprehensive Review

H. pylori is the most common infection in the world and is associated with gastrointestinal and extra-gastrointestinal manifestations, including peptic ulcer disease, gastrointestinal bleeding, and lymphoproliferative disorders. Despite being discovered less than half a century ago, antibiotic resistance, exacerbated by medication non-adherence and inefficacy of proton pump inhibitors, has grown substantially, explaining the rising incidence of refractory H. pylori infection. In this review, we discuss risk factors, treatment options, surveillance and follow-up, as well as emerging therapies for refractory H. pylori.

Cost-Effectiveness, Efficacy, and Safety Analysis of Tailored Therapy in Patients with Helicobacter pylori Infection

Recently in Korea, where triple therapy is accepted as the first-line Helicobacter pylori (H. pylori) eradication treatment, antibiotic resistance to clarithromycin has increased considerably, resulting in eradication rates of less than 80%. We investigated the efficacy of tailored therapy after a clarithromycin resistance test compared with empirical therapy for H. pylori eradication. The cost-effectiveness of H. pylori eradication success was evaluated according to the average medical cost per patient. A total of 364 patients were enrolled in the study. The first-line H. pylori eradication rate was significantly higher in patients who received tailored therapy than in those who received empirical therapy. The total medical costs for the tailored and empirical groups were 46,374 Won and 53,528 Won. The total treatment period for each ultimately successful eradication in the tailored group was 79.8 ± 2.8 days, which is shorter than that of the empirical group (99.2 ± 7.4 days). The rate of eradication-related adverse events for the tailored group and empirical group was 12.9% and 14.8%, respectively. Tailored therapy could be a useful option to achieve a higher successful eradication rate, shorter treatment periods, and lower medical costs than empirical therapy in the era of increasing antibiotic resistance.

Randomized Clinical Trial Comparing Concomitant and Tailored Therapy for Eradication of Helicobacter pylori Infection

As high clarithromycin resistance (>20%) in the Split-Dalmatia region of Croatia hinders the treatment of H. pylori infection, the primary objective of this study was to compare concomitant quadruple with the tailored, personalized therapy as first-line eradication treatment of H. pylori. In an open-label, randomized clinical trial, 80 patients with H. pylori infection were randomly assigned to either concomitant (esomeprazole 40 mg, amoxicillin 1 gr, metronidazole 500 mg, clarithromycin 500 mg, twice daily for 14 days) or tailored therapy in accordance with the results of the antimicrobial susceptibility testing. Eradication status was assessed 4 weeks after treatment. Eradication rates were significantly higher in tailored group than in concomitant group both in intention-to-treat (70 vs. 92.5%, p = 0.010) and per-protocol (87.5 vs. 100%, p = 0.030) analysis in the setting of increasing antibiotic resistance (clarithromycin 37.5%, metronidazole 17.5%, dual resistance 10%). Adverse effects were more frequent in the concomitant group (32.5 vs. 7.5%, p = 0.006). Tailored therapy achieves higher eradication with a lower adverse events rate. With the increasing resistance of H. pylori strains to antibiotic treatment, eradication regimes with such characteristics should be strongly considered as a reasonable choice for first-line treatment.

Empirical or susceptibility-guided treatment for Helicobacter pylori infection? A comprehensive review

Although susceptibility-guided therapy is frequently recommended for Helicobacter pylori infection, the evidence available to date supporting this strategy is limited. The aim of the present article is to review the advantages and limitations of the susceptibility-guided and the empirical strategies to treat this infection. We performed a bibliographic search to identify studies investigating H. pylori susceptibility-guided therapy. Culture is not the only way to assess antibiotic resistance, as different polymerase chain reaction-based approaches have been developed as alternative methods. For detecting H. pylori antimicrobial resistance, a molecular approach based on a stool sample might enable more convenient, time-saving methods. Unfortunately, the antimicrobial susceptibility cannot be obtained in all cases. Furthermore, antibiotic susceptibility testing in clinical practice yields useful information only for a few antibiotics: clarithromycin, metronidazole, and quinolones. In addition, susceptibility towards clarithromycin and metronidazole in vitro does not necessarily lead to eradication in vivo. In the case of H. pylori therapy failure, we should not re-administer any of the antibiotics against which H. pylori has probably become resistant. Our updated meta-analysis showed that susceptibility-guided treatment is not better than empirical treatment of H. pylori infection in first-line therapy if the most updated quadruple regimens are empirically prescribed, and similar efficacy results were also demonstrated with the two strategies for second-line therapy. Cumulative H. pylori eradication rate with several successive rescue therapies empirically prescribed reaches almost 100%. Finally, the studies that have evaluated the cost-effectiveness of the susceptibility-guided treatment have achieved contradictory results. In summary, we can conclude that the evidence is too limited to support the generalized use of susceptibility-guided therapy for H. pylori treatment in routine clinical practice, either as first-line or as rescue treatment. Nevertheless, it would be recommended that susceptibility tests are performed routinely, even before prescribing first-line treatment, in specialized centers with an interest in H. pylori management.

Genotypic and Phenotypic Resistance to Clarithromycin in Helicobacter pylori Strains

BACKGROUND

The increasing prevalence of antimicrobial resistance, together with the lack of novel treatment options, negatively affects successful eradication of Helicobacter pylori. The aim of this study was to investigate genetic mutations in the 23S rRNA genes, which is associated with clarithromycin resistance, and to determine the clinical impact of genotype on phenotypic antimicrobial resistance.

METHODS

A total of 46 H. pylori strains were obtained from 13 patients, before and after unsuccessful eradication with clarithromycin-based triple therapy. The phenotypic resistance of each H. pylori strain was determined by minimum inhibitory concentration against clarithromycin using the serial two-fold agar dilution method. The genomic sequences of 23S rRNA genes were identified through next-generation sequencing, and nucleotide variants were determined based on comparison with genome sequences of the reference strain H. pylori 26695.

RESULTS

Clarithromycin resistance was found in 9 of 13 subjects before treatment and all subjects after unsuccessful eradication. Whole-genome sequencing of the 23S rRNA genes detected 42 mutations on 40 nonidentical loci, including 2147A>G (formerly 2143A>G) and 2146A>G (formerly 2142A>G). All strains with clarithromycin-resistant phenotype had either 2147A>G or 2146A>G mutation. When comparing genotype and phenotype for clarithromycin resistance, there was a significant association between 2147A>G mutation and clarithromycin-resistant phenotype.

CONCLUSIONS

All clarithromycin-resistant strains had either 2146A>G or 2147A>G mutation, suggesting that tests targeting these two mutations may be enough for the prediction of clarithromycin resistance in this population.

Clarithromycin Versus Metronidazole in First-Line Helicobacter Pylori Triple Eradication Therapy Based on Resistance to Antimicrobial Agents: Meta-Analysis

BACKGROUND

International treatment guidelines for Helicobacter pylori infection recommend a proton pump inhibitor (PPI)/amoxicillin/clarithromycin (CAM) regimen (PAC) or PPI/amoxicillin/metronidazole (MNZ) regimen (PAM) as first-line therapy based on culture and sensitivity testing. As incidence rates of antimicrobial agent-resistant strains are changing year by year, it is important to reevaluate the efficacy of eradication regimens. We performed a meta-analysis to evaluate the efficacy and safety of PAC and PAM based on different locations categorized by the reported incidence of CAM- and MNZ-resistant strains.

METHODS

Randomized control trials (RCTs) comparing eradication rates between PAC and PAM first-line treatment up to December 2018 were included. We divided RCTs into four groups based on resistance to CAM (< 15% or ≥ 15%) and MNZ (< 15% or ≥ 15%).

RESULTS

A total of 27 studies (4825 patients) were included. Overall eradication rates between PAC and PAM were similar (74.8% and 72.5%, relative risk (RR): 1.13, 95% confidence interval (CI): 0.91-1.39, P = 0.27) in the intention-to-treat analysis. In areas with low MNZ- and high CAM-resistance rates, PAM had a significantly higher eradication rate than PAC (92.5% vs. 70.8%, RR: 0.29, 95% CI: 0.13-0.68). In areas with high MNZ- and low CAM-resistance rates, the eradication rate with PAC was only 72.9%.

CONCLUSIONS

Overall eradication rates with PAC and PAM were equivalent worldwide. In low MNZ-resistance areas, PAM may be recommended as first-line therapy. However, the efficacy of PAC may be insufficient, irrespective of susceptibility to CAM.

Helicobacter pylori Mutations Detected by Next-Generation Sequencing in Formalin-Fixed, Paraffin-Embedded Gastric Biopsy Specimens Are Associated with Treatment Failure

Helicobacter pylori antibiotic resistance is widespread and increasing worldwide. Routine detection of H. pylori mutations that invoke antimicrobial resistance may be a useful approach to guide antimicrobial therapy and possibly avert treatment failure. In this study, formalin-fixed, paraffin-embedded (FFPE) gastric biopsy specimens from a cohort of individuals from northern Ohio in the United States were examined using a next-generation sequencing (NGS) assay to detect H. pylori mutations that are known to confer resistance to clarithromycin, levofloxacin, and tetracycline. From January 2016 to January 2017, 133 H. pylori-infected gastric biopsy specimens were identified histologically and subsequently analyzed by NGS to detect mutations in gyrA, 23S rRNA, and 16S rRNA genes. The method successfully detected H. pylori in 126 of 133 cases (95% sensitivity). Mutations conferring resistance were present in 92 cases (73%), including 63 cases with one mutation (50%) and 29 cases with mutations in multiple genes (23%). Treatment outcomes were available in 58 cases. Sixteen of the 58 cases failed therapy (28%). Therapy failure correlated with the number of mutated genes: no failure in cases with no mutations (0/15), 19% (5/27) failure in cases with one gene mutation, and 69% (11/16) failure in cases with more than one mutated gene. Common 23S rRNA mutations (A2142G or A2413G) were present in 88% (14/16) of failed cases as opposed to in only 10% (4/42) of eradicated cases (P < 0.001). This NGS assay can be used on remnant specimens collected during standard-of-care testing to detect mutations that correlate with increased risk of treatment failure. A prospective study is needed to determine if the risk of treatment failure can be decreased by using this assay to guide antibiotic therapy.

Molecular diagnosis of Helicobacter pylori infection in gastric biopsies: Evaluation of the Amplidiag® H. pylori + ClariR assay

BACKGROUND

Adapted treatments for Helicobacter pylori infection, guided by determining antimicrobial resistance, are associated with high eradication rates. We evaluated the performance of the Amplidiag^® H. pylori + ClariR PCR assay (Amplidiag^® ) for detecting H. pylori and its clarithromycin resistance from gastric biopsies taken during endoscopy in comparison to culture and our "in-house" PCR.

MATERIALS AND METHODS

A total of 127 gastric biopsies were analyzed (98 adults; 29 children). Culture, PCR Amplidiag^® , and in-house PCR were performed in parallel. The in-house PCR combined amplification and sequencing of a 267-bp fragment of the H. pylori 23S rRNA gene. Discrepancies were controlled by amplification of glmM gene.

RESULTS

For detection of H. pylori, Amplidiag^® and the in-house PCR were concordant in 118 of 127 of cases: 66 negative and 52 positive. Discrepancies were observed in nine cases, all with low bacterial load: Amplidiag^® did not detect seven biopsies positive on in-house PCR but detected two positive biopsies that were negative on in-house PCR. Among the 19 of 52 (36%) H. pylori cases resistant to clarithromycin, only four biopsies with mixed populations exhibited discordant results between the two PCR methods. The A2142T mutation was not detected by Amplidiag^® . With the in-house PCR and amplified glmM gene as the reference method, the sensitivity and specificity of Amplidiag^® was 88.5% (95% confidence interval 83-94.1) and 100%.

CONCLUSION

This study demonstrated the high sensitivity of the PCR-based Amplidiag^® H. pylori test, especially with low H. pylori load, and the probability of its clarithromycin resistance analysis. For clinical use, a well-designed trial with a large scale of samples may still be needed.

Helicobacter pylori antimicrobial resistance during a 5-year period (2013-2017) in northern Spain and its relationship with the eradication therapies

BACKGROUND

Antibiotic resistance is the main cause for Helicobacter pylori therapy failure. Frequently, empirical regimens have been recommended in patients with various H. pylori eradication failures. In patients with H. pylori-resistant to various families of antibiotics, the treatment guided by antimicrobial susceptibility testing allows the achievement of good eradication rates.

AIM

To evaluate the effectiveness of susceptibility-guided antimicrobial treatment for H. pylori infection in patients with resistance to one or various families of antibiotics.

METHODS

A total of 3170 consecutive patients infected by H. pylori during 2013-2017 were tested for antimicrobial susceptibility. 66.6% patients showed resistance to one antimicrobial, 18.9% to two, and 2.4% to three families of antibiotics. A cohort of 162 H. pylori-positive patients were enrolled in this study. Forty-three with single H. pylori resistance to clarithromycin (CLR) were treated with omeprazole (PPI), amoxicillin (AMX), and levofloxacin (LVX)-OAL (31 subjects) or omeprazole, AMX, and metronidazole (MTZ)-OAM (12 patients) and 77 patients with dual H. pylori resistance (51 to CLR and MTZ, 12 to CLR plus LVX, and 14 to MTZ plus LVX) received OAL or OBTM (PPI, bismuth subcitrate, tetracycline, and MTZ), OAM, and OAC, respectively. Other 42 patients with triple H. pylori resistance (CLR, LVX, and MTZ) were treated with PPI, AMX, and rifabutin-OAR (18 subjects), PPI, AMX, and doxycycline-OAD (8), OADB (7), OBTM (6), and ODBR (3). All subjects received standard doses for 10 days. Eradication rate was confirmed by 13 C-UBT. Adverse events were assessed by a questionnaire.

RESULTS

Intention-to-treat analysis demonstrates that eradication rates using triple therapies in patients with H. pylori resistance to one and to two families of antibiotics were 93% and 94.8%, respectively. In subjects with H. pylori-resistant to three families of antibiotics, cure rate was higher in naïve patients treated with OAR-10 days compared to those treated with bismuth-containing quadruple therapies (90% vs 75%). Adverse events were limited (18 of 162, 11.1%), all of them mild-moderate.

CONCLUSIONS

The implementation of susceptibility-guided triple therapy for 10 days leads to eradication rate ≥95% in naïve patients with H. pylori resistance to one or two families of antimicrobials. In naïve patients with H. pylori resistance to three families, OAR treatment achieved a 90% of eradication.

Prevalence of Antibiotic Resistance in Helicobacter pylori: A Systematic Review and Meta-analysis in World Health Organization Regions

BACKGROUND & AIMS

In 2017, the World Health Organization (WHO) designated clarithromycin-resistant Helicobacter pylori a high priority for antibiotic research and development. However, there are no clear data on the global distribution of resistance or its clinical effects. We performed a systematic review and meta-analysis to assess the distribution of H pylori resistance to commonly used antibiotics and to measure the association between antibiotic resistance and treatment failure.

METHODS

We searched publication databases for studies that assessed rates of H pylori resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, or tetracycline. Pooled estimates of primary and secondary resistance and 95% confidence intervals (CIs) were grouped by WHO region. The association between antibiotic resistance and treatment failure was measured by extracting data on treatment efficacy in patients with resistant and susceptible isolates and pooling odds ratios with 95% CIs.

RESULTS

We identified 178 studies, comprising 66,142 isolates from 65 countries. Primary and secondary resistance rates to clarithromycin, metronidazole, and levofloxacin were ≥15% in all WHO regions, except primary clarithromycin resistance in the Americas (10%; 95% CI, 4%-16%) and South-East Asia region (10%; 95% CI, 5%-16%) and primary levofloxacin resistance in the European region (11%; 95% CI, 9%-13%). There was considerable heterogeneity (I2 > 75%) among all analyses-this might have resulted from the grouping of resistance rates by country. Increasing antibiotic resistance was observed in most WHO regions. Resistance to clarithromycin was significantly associated with failure of clarithromycin-containing regimens (odds ratio, 6.97; 95% CI, 5.23-9.28; P < .001).

CONCLUSIONS

Resistance of H pylori to antibiotics has reached alarming levels worldwide, which has a great effect on efficacy of treatment. Local surveillance networks are required to select appropriate eradication regimens for each region.

Twelve-day quintuple regime containing four antibiotics as a rescue therapy for Helicobacter pylori eradication in the central region of Portugal

BACKGROUND

Helicobacter pylori eradication rates with standard triple therapy in many countries are clinically unacceptable. Fluoroquinolone resistance is increasing and jeopardizing second-line regimens. There is a growing need for an effective strategy in patients who failed previous therapies.

METHODS

This is a single-center, non-randomized clinical study conducted in the central region of Portugal. Sixty-four patients were included with a positive 13C-urea breath test (UBT) or histology for H. pylori, and at least one failed eradication attempt. The patient cohort included 71.7% of females with a median of age of 52 (range 23-87). They were treated with a twelve-day regimen consisting of a proton-pump inhibitor (PPI) bid, amoxicillin at 1,000 mg 12/12 h and levofloxacin at 500 mg bid during the first seven days, followed by PPI bid, clarithromycin at 500 mg 12/12h and either tinidazole or metronidazole at 500 mg bid/tid for five days. Eradication was assessed by UBT. The local Ethics Committee approved this study.

RESULTS

Eradication therapy was prescribed due to dyspepsia (66.7%), peptic ulcer (10%) and thrombocytopenia (8.3%). The median number of failed therapies was one (range 1-4). The eradication rate was 64.6% according to an intention-to-treat analysis (95% CI: 53-77%), and 70% by the per-protocol analysis (95% CI: 58-82%). Age, smoking, indication for eradication, previous therapies and the use of a second-generation or full-dose PPI did not affect success rates.

CONCLUSIONS

Even though treatment with four antibiotics was used, this "reinforced" therapy achieved suboptimal results. This fact highlights the lack of effective H. pylori antimicrobials and suggests that second-line treatment in our region should be prescribed according to susceptibility testing.

Antimicrobial susceptibility testing before first-line treatment for Helicobacter pylori infection in patients with dual or triple antibiotic resistance

AIM

To evaluate the efficacy of antimicrobial susceptibility-guided therapy before first-line treatment for infection in patients with dual or triple antibiotic resistance.

METHODS

A total of 1034 patients infected by Helicobacter pylori (H. pylori) during 2013-2014 were tested for antimicrobial susceptibility. 157 of 1034 (15%) patients showed resistance to two (127/1034; 12%) and to three (30/1034; 3%) antibiotics. Sixty-eight patients with dual H. pylori-resistance (clarithromycin, metronidazole or levofloxacin) were treated for 10 d with triple therapies: OAL (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and levofloxacin 500 mg b.i.d.) 43 cases, OAM (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and metronidazole 500 mg b.i.d.) 12 cases and OAC (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d.) 13 cases based on the antimicrobial susceptibility testing. Twelve patients showed triple H. pylori-resistance (clarithromycin, metronidazole and levofloxacin) and received for 10 d triple therapy with OAR (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and rifabutin 150 mg b.i.d.). Eradication was confirmed by 13C-urea breath test. Adverse effects and compliance were assessed by a questionnaire.

RESULTS

Intention-to-treat eradication rates were: OAL (97.6%), OAM (91.6%), OAC (92.3%) and OAR (58.3%). Cure rate was significantly higher in naïve patients treated with OAR-10 compared to patients who had two or three previous treatment failures (83% vs 33%). Adverse events rates for OAL, OAM, OAC and OAR were 22%, 25%, 23% and 17%, respectively, all of them mild-moderate.

CONCLUSION

Antimicrobial susceptibility-guided triple therapies during 10 d for first-line treatment leads to an eradication rate superior to 90% in patients with dual antibiotic H. pylori resistance.

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.

Importance of antimicrobial susceptibility testing for the management of eradication in Helicobacter pylori infection

The management of Helicobacter pylori (H. pylori) infection treatment differs from the common treatment protocol for other infectious diseases. Because culture- or molecular-guided approaches face several practical issues, such as the invasive procedures required to obtain gastric biopsy specimens and the lack of availability of routine laboratory testing in some places, H. pylori treatment includes the administration of two or three empirically selected antibiotics combined with a proton pump inhibitor rather than evidence-based eradication treatment. The efficacy of empirical therapy is decreasing, mostly due to increasing multiple resistance. Multiresistance to levofloxacin, clarithromycin, and metronidazole, which are commonly used in empirical treatments, appears to have increased in many countries. Mutations play a primary role in the antimicrobial resistance of H. pylori, but many different mechanisms can be involved in the development of antibiotic resistance. Determining and understanding these possible mechanisms might allow the development of new methods for the detection of H. pylori and the determination of antimicrobial resistance. A treatment based on the detection of antimicrobial resistance is usually more effective than empirical treatment. Nevertheless, such an approach before treatment is still not recommended in the Maastricht guidelines due to the difficulty associated with the routine application of available culture- or molecular-based susceptibility tests, which are usually administered in cases of treatment failure. The management of first and rescue treatments requires further research due to the steadily increase in antimicrobial resistance.

Clarithromycin resistance in Helicobacter pylori and its molecular determinants in Northern Spain, 2013-2015

OBJECTIVES

Clarithromycin resistance (CLR-R) is the main reason for failure of Helicobacter pylori infection treatment, which is frequently empirically prescribed due to the erroneous belief that culture for susceptibility testing is difficult. The aim of this study was to determine CLR-R in a region of southern Europe and to evaluate the utility of a PCR sequencing assay applied on gastroduodenal biopsies in detecting H. pylori and clarithromycin (CLR) susceptibility.

METHODS

The susceptibility of all H. pylori isolates obtained by culture during 2013-2015 was determined by Etest. During 2014-2015, H. pylori detection and CLR susceptibility were also studied by PCR followed by sequencing performed on gastroduodenal biopsies. Point mutations in the 23S rRNA gene were studied in all CLR-resistant isolates in 2014.

RESULTS

Of 1986 H. pylori isolates obtained by culture (63 from children and 1923 from adults), 349 (17.6%) were CLR-resistant [21/63 (33.3%) in children and 328/1923 (17.1%) in adults; P<0.001], of which 31.5% were also resistant to levofloxacin. The main mutations detected were A2147G (79.8%), A2146G (17.2%) and A2146C (2%). Concordance between the PCR sequencing assay on biopsies and CLR susceptibility by Etest after culture was 89.8%.

CONCLUSIONS

CLR-R was high in Gipuzkoa, northern Spain. The molecular PCR method performed directly on biopsies was a good alternative to the traditional Etest susceptibility method and was an aid when culture was non-viable.

Appropriateness of Repeating Helicobacter pylori Culture and Susceptibility Testing Following Failure of Individualized Antibiotic Therapy

BACKGROUND

Current guidelines recommend direct Helicobacter pylori culture and antibiotic susceptibility testing following 2 failed eradication attempts. If this process is followed and yet subsequent treatment is unsuccessful, it is unclear whether susceptibility testing should be repeated. This is the first study to examine the appropriateness of repeated H. pylori culture and susceptibility testing following failure of individualized treatment.

METHODS

Between 2007 and 2014, consecutive patients who underwent at least 2 upper gastrointestinal endoscopies with H. pylori culture and susceptibility testing at our institution following several treatment failures were retrospectively identified. Antibiotic susceptibility was recorded and linked to demographic data.

RESULTS

A total of 68 cultures from 34 patients were included (12 (35.3%) men, 41.4 ± 16.6 years), and 20 (58.8%) cultures had a different antibiotic susceptibility profile on repeat testing (8 (23.5%) with new susceptibility and 13 (38.2%) with new resistance). Acquired resistance to clarithromycin, levofloxacin and metronidazole was observed in 9 (26.5%), 2 (5.9%) and 10 (29.4%) cultures, respectively. Subjects with resistance to ≤1 antibiotic at baseline were more likely to develop resistance to at least 1 antibiotic on subsequent culture, compared to subjects with resistance to ≥2 antibiotics at baseline (13 (100%) vs. 5 (23.8%), p < 0.01).

CONCLUSION

Repeating H. pylori culture and susceptibility testing usually yields new antimicrobial susceptibility data. However, the clinical usefulness of this approach remains unclear.

Helicobacter pylori Clarithromycin Resistance and Treatment Failure Are Common in the USA

BACKGROUND

Helicobacter pylori antibiotic resistance leads to frequent treatment failure. However, the current US prevalence of H. pylori clarithromycin resistance and treatment failure is unknown.

AIMS

To determine the prevalence of clarithromycin-resistant H. pylori and its impact on treatment failure in the USA.

METHODS

A multicenter, retrospective, cohort study for clarithromycin-resistant H. pylori was conducted over four academic medical centers in different geographic regions of the USA. Gastric biopsy material, residual from standard clinical pathologic examination, was examined for clarithromycin resistance by DNA sequencing of H. pylori 23S rRNA.

RESULTS

One hundred and twenty-four cases of H. pylori gastritis were examined from medical centers in four different geographic regions of the USA. The overall prevalence of clarithromycin resistance was 32.3 % (range 23.1-45.8 %). There was no significant difference in the prevalence of clarithromycin resistance by study site, gender, age, or race/ethnicity. In a subset of 67 patients that had clinical follow-up data, the overall prevalence of clarithromycin resistance was 31.3 %. There was a 2.9-fold increase (p = 0.002) in treatment failure for cases with clarithromycin resistance (57.1 %) compared to wildtype H. pylori (19.6 %).

CONCLUSIONS

H. pylori clarithromycin resistance in the USA exceeds the estimated 20 % prevalence compatible with successful empiric antibiotic therapy. This resistance resulted in a significant rate of treatment failure in all sites surveyed. Empiric therapy in the USA should be used with caution until there is better regional or local determination of H. pylori antibiotic resistance.

Systematic review: third-line susceptibility-guided treatment for Helicobacter pylori infection

BACKGROUND

Susceptibility-guided therapies (SGTs) have been proposed as preferable to empirical rescue treatments after two treatment failures. The aim of this study was to perform a systematic review and meta-analysis evaluating the effectiveness and efficacy of SGT as third-line therapy.

METHODS

A systematic search was performed in multiple databases. Studies reporting cure rates of Helicobacter pylori with SGT in third-line therapy were selected. A qualitative analysis describing the current evidence and a pooled mean analysis summarizing the cure rates of SGT in third-line therapy was performed.

RESULTS

No randomized controlled trials or comparative studies were found. Four observational studies reported cure rates with SGT in third-line treatment, and three studies which mixed patients with second- and third-line treatment also reported cure rates with SGT. The majority of the studies included the patients when culture had been already obtained, and so the effectiveness of SGT and empirical therapy has never been compared. A pooled mean analysis including four observational studies (283 patients) showed intention-to-treat and per-protocol eradication rates with SGT of 72% (95% confidence interval 56-87%; I(2) : 92%) and 80% (95% confidence interval 71-90%; I(2) : 80%), respectively.

CONCLUSIONS

SGT may be an acceptable option as rescue treatment. However, cure rates are, at best, moderate and this approach has never been compared with a well-devised empirical therapy. The evidence in favor of SGT as rescue therapy is currently insufficient to recommend its use.

Helicobacter pylori therapy: a paradigm shift

Helicobacter pylori (H. Pylori) is a leading cause of gastroduodenal disease, including gastric cancer. H. pylori eradication therapies and their efficacy are summarized. A number of current treatment regimens will reliably yield >90% or 95% cure rates with susceptible strains. None has proven to be superior. We show how to predict the efficacy of a regimen in any population provided one knows the prevalence of antibiotic resistance. As with other infectious diseases, therapy should always be susceptibility-based. Susceptibility testing should be demanded. We provide recommendations for empiric therapies when that is the only option and describe how to distinguish studies providing misinformation from those providing reliable and interpretable data. When treated as an infectious disease, high H. pylori cure rates are relatively simple to reliably achieve.

Antimicrobial Susceptibility-Guided Therapy Versus Empirical Concomitant Therapy for Eradication of Helicobacter pylori in a Region with High Rate of Clarithromycin Resistance

BACKGROUND

Nonbismuth quadruple (concomitant) regimen is recommended for first-line empirical Helicobacter pylori (HP) eradication treatment when clarithromycin resistance is more than 15-20%. Our objective was to evaluate the efficacy and tolerability of concomitant versus antimicrobial susceptibility-guided treatment in an area with high rates of clarithromycin resistance.

METHODS

Three hundred consecutive HP-infected patients received antimicrobial susceptibility-guided therapy or empirical concomitant therapy for 10 days. The concomitant regimen was omeprazole (20 mg/12 hour), amoxicillin (1 g/12 hour), clarithromycin (500 mg/12 hour), and metronidazole (500 mg/12 hour) (OACM). Patients diagnosed by culture received one of three combinations of antibiotics based on susceptibility results: omeprazole, amoxicillin, and clarithromycin (OAC); omeprazole, amoxicillin, and levofloxacin (OAL); or omeprazole, amoxicillin, and metronidazole (OAM), at the aforementioned doses (and 500 mg/12 hour in the case of levofloxacin). Eradication was confirmed with a (13)C urea breath test, 6 weeks after treatment. Adverse events and adherence were assessed with questionnaires and reviewing medication sachets.

RESULTS

The mean age was 50 years, 59% were women, and 14% had peptic ulcers. Concomitant and antimicrobial susceptibility-guided eradication rates were, respectively, 87% and 94% by intention-to-treat (p = .08) and 89% and 95% (p = .08) per protocol per-protocol analysis. Adverse effects were reported in 31% of patients on OACM and 15% of those on susceptibility-guided therapy (p < .05).

CONCLUSIONS

For HP eradication in a region with high rates of multiple drug resistance, antimicrobial susceptibility-guided therapy is more effective than empirical concomitant therapy.

Ten-day triple therapy versus sequential therapy versus concomitant therapy as first-line treatment for Helicobacter pylori infection

BACKGROUND AND AIM

Clarithromycin-based triple therapy (TT) is the first-line treatment for Helicobacter pylori infection in Singapore. There is awareness that TT may no longer be effective due to increased clarithromycin resistance rates. Sequential therapy (ST) and concomitant therapy (CT) are alternative treatment regimens. This study aimed to compare the efficacy of 10-day TT, ST, and CT as first-line treatment for H. pylori infection.

METHODS

A randomized study conducted in a teaching hospital. Patients aged 21 years and older with newly diagnosed H. pylori infection were randomized to 10-day TT, ST, or CT. Treatment outcome was assessed by 13-carbon urea breath test at least 4 weeks after therapy. Intention to treat (ITT), modified ITT (MITT), and per protocol (PP) analyses of the eradication rates were performed.

RESULTS

A total of 462 patients were enrolled (ST: 154; TT 155; CT 153). Patient demographics were similar. Eradication rates for ST versus TT versus CT: ITT analysis: 84.4% versus 83.2% versus 81.7% (P = not significant [NS]); MITT analysis: 90.3% versus 92.1% versus 94.7% (P = NS); PP analysis: 94.1% versus 92.8% versus 95.4% (P = NS). Antibiotic resistance rates for amoxicillin, clarithromycin, and metronidazole were 4.7%, 17.9%, and 48.1%, respectively. Dual clarithromycin and metronidazole resistance occurred in 7.5%. Dual resistance and lack of compliance were predictors of treatment failure.

CONCLUSIONS

TT, ST, and CT all achieved eradication rates above 80% on ITT and above 90% on MITT and PP analyses. Dual resistance and lack of compliance were predictors of treatment failure (clinicaltrials.gov: NCT02092506).

Systematic review and meta-analysis: susceptibility-guided versus empirical antibiotic treatment for Helicobacter pylori infection

BACKGROUND

The cure rate of standard triple therapy for Helicobacter pylori infection is unacceptably low. Susceptibility-guided therapies (SGTs) have been proposed as an alternative to standard empirical treatments. The aim of this study was to perform a systematic review and meta-analysis evaluating the efficacy of SGTs.

METHODS

A systematic search was performed in multiple databases. Randomized controlled trials comparing cure rates of SGTs versus those of empirical therapy were selected and analysed separately for first- and second-line treatments. A meta-analysis was performed using risk ratio (RR) and number needed to treat (NNT) to measure the effect.

RESULTS

Twelve studies were included in the meta-analysis. In first-line treatment, SGT was more efficacious than empirical 7-10 day triple therapy (RR 1.16, 95% CI 1.10-1.23, I (2) = 33%; NNT = 8). Most studies used a 7-10 day triple therapy and randomized the patients after endoscopy and/or culture, thus precluding the comparison of SGT versus non-invasive testing and empirical treatment in clinical practice. For second-line therapy, only four studies were found. Results were highly heterogeneous and no significant differences were found (RR 1.11, 95% CI 0.82-1.51, I (2) = 87%).

CONCLUSIONS

Once endoscopy and culture have been performed, SGT is superior to empirical 7 or 10 day triple therapy for first-line treatment. Further studies are needed to evaluate the effectiveness of SGT in clinical practice, especially when compared with currently recommended first-line quadruple therapies.

Helicobacter pylori Infection in Children. Antimicrobial Resistance and Treatment Response

BACKGROUND

The aim of this study was to determine the appropriateness of the recent recommendations for managing Helicobacter pylori infection in children in a university hospital in Southern Europe. Antimicrobial resistance and response to eradication therapy were also determined.

MATERIALS AND METHODS

The presence of H. pylori was studied in 143 children: by gastric biopsy culture (GBC), (13)C-urea breath test (UBT) and stool antigen immunochromatography test (SAIT) in 56 children; by GBC and UBT in 20, by GBC and SAIT in 18, and by GBC alone in 49. Antimicrobial susceptibility was determined by E-test. Infection was defined as a positive culture or positivity in both UBT and SAIT. Disease progression was studied in 118 patients. First evaluation of symptoms was carried out at 3-6 months after diagnosis and/or after treatment of the infection.

RESULTS

H. pylori was detected in 74 from the 143 children analyzed (100% GBC positive, 98.1% UBT positive, and 58.1% SAIT positive). The main symptom was chronic abdominal pain (n = 121). Macroscopic antral nodularity was observed in 29.7% of infected patients and in 5.8% of uninfected patients, respectively. Resistance to clarithromycin and metronidazole was found in 34.7 and 16.7%, respectively. Eradication when susceptible antimicrobials were used occurred in 78.7% (48/61) versus 37.5% (3/8) when the treatment included a drug with resistance (p = .024). In patients with recurrent abdominal pain, symptoms resolved in 92.9% (39/42) patients with HP eradication versus 42.9% (6/14) without HP eradication (p < .001).

CONCLUSION

Treated patients often failed to meet the criteria established in the guidelines for H. pylori diagnostic screening and treatment because most of them had only recurrent abdominal pain, but remission of their symptoms was associated with H. pylori eradication.

Evaluation of Exalenz Bioscience's BreathID for Helicobacter pylori detection

Carbon-labeled urea breath tests, which have high sensitivity and specificity, are the preferred method used in epidemiological studies, screening dyspeptic patients and assessing eradication or recurrence of Helicobacter pylori infection. The principle of the (13)C-urea breath test relies upon the ability of the H. pylori urease to hydrolyze the orally administered (13)C-urea. The BreathID (Exalenz Bioscience Inc., Union, NJ, USA) provides a competitive solution for breath testing, including unique features such as automatic continuous breath collection and analysis. This is an unattended convenient test, with no human error as the correct part of the breath is collected and patients' assistance is not required. The test results are available in real time at the point of care and enable shortened breath testing procedures. Additionally, several studies showing expanded utility of the BreathID in pediatrics, after therapy and during proton pump inhibitors intake, further support the safety and performance of the BreathID in the diagnosis of H. pylori.

Use of the Optum Labs Data Warehouse to assess test ordering patterns for diagnosis of Helicobacter pylori infection in the United States

We surveyed national Helicobacter pylori diagnostic testing practices and diagnoses using commercial and Medicare medical claims data from Optum Labs (Cambridge, MA). Serologic testing for antibodies to H. pylori remains the most commonly ordered diagnostic test despite recent expert recommendations. Changes in reimbursement for serologic testing will likely drive future provider ordering practices.

Clarithromycin for first-line treatment of Helicobacter pylori infection after culture in high-resistance regions

OBJECTIVE

Resistance to antibiotics is the major cause of treatment failure of Helicobacter pylori (HP) infection. The culture-guided triple therapy (chosen on the basis of a preliminary in-vitro susceptibility test) might help to increase treatment success in high antibiotic resistance regions. The aim of this study was to evaluate the effectiveness of treatment with clarithromycin in patients with clarithromycin-sensitive culture compared with patients treated empirically.

METHODS

In this prospective and controlled trial, 111 naive HP-positive patients were randomized to receive standard triple therapy omeprazole (20 mg twice daily), amoxicillin (1 g twice daily), and clarithromycin (500 mg twice daily) for 10 days (OAC) after antimicrobial susceptibility testing if there was no resistance to clarithromycin (ClariS) or empirical 10-day OAC for first-line therapy of HP (ClariNA). Eradication was confirmed using the C-labelled urea breath test 6 weeks after therapy. Our primary outcome was HP eradication. Treatment adherence and adverse effects were recorded.

RESULTS

The effectiveness of eradication by protocol with 10-day OAC therapy in the ClariS was 94% [95% confidence interval (CI): 0.83-0.98], which was 22% higher than ClariNA 72% (95% CI: 0.58-0.85; P=0.006). The odds ratio of eradication in ClariS was 1.30 (95% CI: 1.10-1.60; P<0.05 by logistic regression) and the number needed to treat was 5 (95% CI: 3-13). We found no significant difference in the occurrence of adverse effects or in compliance between the two groups.

CONCLUSION

The eradication rate was significantly higher with clarithromycin-based triple therapy for patients with clarithromycin-susceptible HP isolates compared with those for whom no information on the corresponding susceptibility was available (ClinicalTrials.gov number NCT01486082).

Antibiotic resistance of clinical isolates of Helicobacter pylori in Zhejiang Province

AIM: To analyze the antibiotic resistance of clinical isolates of Helicobacter pylori (H. pylori) to guide clinical anti-infection therapy.

METHODS: A total of 713 strains of H. pylori isolated from gastroscopic specimens were collected from April to June 2013, and the resistance of these strains to metronidazole, clarithromycin, amoxicillin, gentamicin, furazolidone, levofloxacin and moxifloxacin were analyzed.

RESULTS: Of the 713 strains of H. pylori, the rate of resistance to metronidazole (94.7%) was the highest among the seven antibiotics tested, followed by those to clarithromycin (16.1%), levofloxacin (19.5%) and moxifloxacin (19.5%). The rates of resistance to amoxicillin, gentamicin and furazolidone were all 0.0%.

CONCLUSION: Amoxicillin, gentamicin and furazolidone should be applied as the preferred antibiotics for the treatment of H. pylori in this area due to the very low rates of drug resistance. Metronidazole should not be applied as the first-line antibiotic due to the higher resistance rate. Clarithromycin, levofloxacin and moxifloxacin should be selected in bismuth quadruple therapy or guided by susceptibility testing due to their higher resistance rates. The patterns of resistance to levofloxacin and moxifloxacin were entirely consistent, suggesting the same resistance mechanisms; therefore, only one of them should be selected.

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.

Approach to Helicobacter pylori infection in geriatric population

The prevalence of Helicobacter pylori (H. pylori) infection and its complications increase with age. The majority of infected individuals remain asymptomatic throughout the life but 10%-20% develops peptic ulcer disease and 1% gastric malignancies. The incidence of ulcers and their complications are more common in the older population resulting in higher hospitalization and mortality rates. The increased use of medications causing gastric mucosal damage and the decreased secretion of protective prostaglandins in elderly are major factors increasing gastric mucosal sensitivity to the destructive effects of H. pylori. Due to higher prevalence of gastrointestinal (GI) malignancies, upper GI endoscopy is mostly preferred in elderly for the diagnosis of infection. Therefore, “endoscopy and treat” strategy may be more appropriate instead of “test and treat” strategy for dyspeptic patients in older age. Urea breath test and stool antigen test can be used for control of eradication, except for special cases requiring follow-up with endoscopy. The indications for treatment and suggested eradication regimens are similar with other age groups; however, the eradication failure may be a more significant problem due to high antibiotic resistance and low compliance rate in elderly. Multidrug usage and drug interactions should always be considered before starting the treatment. This paper reviews briefly the epidemiology, diagnosis, disease manifestations, and treatment options of H. pylori in the geriatric population.

Antimicrobial resistance and characteristics of eradication therapy of Helicobacter pylori in Japan: a multi-generational comparison

BACKGROUND

Eradication of Helicobacter pylori (H. pylori) at a younger age is considered to be effective in preventing gastric cancer. This study assessed the characteristics of eradication therapy in young patients.

MATERIALS AND METHODS

We enrolled 1073 patients with H. pylori infection between 2000 and 2013. The subjects were divided into three groups according to age into the young (≤30 years), middle-aged (31-50 years), and elder (≥51 years) groups. We also examined 472 cases to investigate clinical eradication characteristics.

RESULTS

The rate of clarithromycin (CAM) resistance was 57.9%, 34.5%, and 35.2% in the young, middle-aged, and elder group, respectively, in 2012-2013 and was significantly higher in the young group than in the elder group (p = .01). Metronidazole (MNZ) resistance was similar among the three groups at each time point. While CAM resistance rose over the study period, MNZ resistance was noted to have decreased of late. The overall initial eradication success rate was 91.9% (95% CI, 89.1-94.1) in our cohort. Eradication efficiency was comparable in the young, middle-aged, and elder group at 94.3% (95% CI, 87.4-97.5), 90.2% (95% CI, 82.9-94.6), and 91.8% (95% CI, 88.1-94.5) respectively. Side effects such as skin rash were observed in 14.8%, 3.9%, and 3.5% of the respective groups. There were significant differences in the incidence of side effects between the young group and other groups (p < .05, respectively).

CONCLUSION

Since CAM resistance and the incidence of side effects are higher in young individuals, it is especially important to select eradication regimens based on testing for antimicrobial susceptibility.

Culture-guided treatment approach for Helicobacter pylori infection: Review of the literature

The progressive loss of efficacy of standard eradication therapies has made the treatment of Helicobacter pylori (H. pylori) more challenging than ever. Endoscopic-guided antibiotic susceptibility testing had previously been suggested to guide treatment after failure of second-line therapies. However, its role has expanded over the years, in accordance with the current Maastricht Guidelines. Several authors have dealt with this topic, developing both efficacy trials and cost-effectiveness trials against resistant H. pylori infections as well as infections in naïve patients. However, results are not homogeneous enough to provide definite advice, because antibiotic resistance is not the only reason for treatment failure. Moreover, the culture-guided approach is surrounded by many practical issues, such as the availability of both endoscopy units and microbiology laboratories, and the need for a standard of quality that cannot be satisfied everywhere. Finally, pre-treatment susceptibility testing should be part - and not the only weapon - of a targeted, personalized strategy to overcome H. pylori infection.

Treatment of Helicobacter pylori infection 2013

This review summarizes important studies regarding Helicobacter pylori therapy published from April 2012 up to March 2013. To begin with, the updated European Consensus Guidelines were published last year, highlighting the role of bismuth and nonbismuth quadruple regimen as first-line treatments. Cure rates for standard triple therapy remain acceptable in quite a few settings nowadays, and some reports on innovative triple therapies look promising. One study evaluating bismuth quadruple therapy as first-line therapy was reported. Regarding nonbismuth quadruple regimens, there is a trend of superiority emerging for the "concomitant" therapy over the "sequential" regimen. "Hybrid" therapy, a combination of sequential and concomitant therapy, has also shown advantage over sequential therapy. Levofloxacin-based therapies appear to be useful and versatile in second- and third-line therapies, with interesting results for newer generation quinolones, which may partially overcome antibiotic resistance. Some promising works have been reported for bismuth-based rescue therapy, using individualized therapies upon antimicrobial information, as well as for rifabutin fourth-line therapy. Probiotics appear to have an effect in terms of reducing side effects and improving compliance, but data on improvement of eradication rates remain controversial.

[Update on the efficacy of triple therapy for Helicobacter pylori infection and clarithromycin resistance rates in Spain (2007-2012)]

INTRODUCTION

Triple therapy, which remains the standard treatment for Helicobacter pylori infection, should be discouraged when its efficacy is lower than 80% or when clarithromycin resistance rates are above 15-20%.

AIM

To update the available evidence on the effectiveness of triple therapy and clarithromycin resistance rates in adults in Spain over the last 6 years.

METHODS

A literature search (2007-2012) was conducted in Medline and the abstracts books of the annual meetings of several Spanish gastroenterological and microbiological congresses. The search terms were « Helicobacter pylori », « Spain » and « clarithromycin ». Studies were selected if they included triple therapy consisting of a proton pump inhibitor with clarithromycin and amoxicillin or if they analyzed H. pylori clarithromycin susceptibility in treatment-naïve patients.

RESULTS

There were five articles and nine abstracts (3147 patients) on triple therapy, which showed a mean cure rate of 70.8% (95% CI = 66-76%). When stratified by the duration of therapy, the mean cure rates were 68.8% (60-76%) for 7-day regimens and 71.76% (68-78%) for 10-day regimens. For clarithromycin resistance rates, four articles and five abstracts (1709 patients) revealed a mean resistance rate of 18.3% (13-22%).

CONCLUSIONS

The efficacy of triple therapy seems to be unacceptable in recent studies conducted in Spain, possibly associated with clarithromcyin resistance rates higher than previously reported.

Changes in Antibiotic Susceptibility of Helicobacter pylori in the Course of Eight Years in the Zaanstreek Region in The Netherlands

Background. Failure of anti-Helicobacter therapy is the result noncompliance and resistance to the prescribed antibiotics. Aim. Antibiotic susceptibility of H. pylori was determined in native Dutch patients and patients of Turkish descent. Methods. In a period of eight years a total of 925 strains of H. pylori were cultured. Bacterial susceptibility was successfully determined in 746 (80.6%) of these isolates. Three hundred and nine strains (33%) originated from patients of Turkish descent. Results. In total clarithromycin resistance was found in 146 (20.5%) strains, metronidazole resistance in 147 (19.9%) strains. Amoxicillin resistance was found to be present in five strains. There is a slight but nonsignificant decrease in the percentage of clarithromycin-resistant strains in the consecutive period of eight years from 20% to 18%. No changes were seen in the consecutive years in metronidazole resistance. The number of clarithromycin-resistant strains decreased in Turkish patients, not in native Dutch patients. Conclusion. Resistance did not change significantly in consecutive years. But clinicians should take not only the antibiotic history into account but also ethnicity before prescribing metronidazole or clarithromycin.