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

Long-term evaluation of Helicobacter pylori screening in school health checkups: an 11-year study in Japan

BACKGROUND

The eradication of Helicobacter pylori (H. pylori) at a younger age is considered effective in preventing gastric cancer. Toward this goal, we introduced primary H. pylori screening into routine high school health screenings in 2007. The present study aimed to elucidate the clinicopathological characteristics of H. pylori-infected students and evaluate the effectiveness of H. pylori screening in high school populations.

METHODS

Primary screening using a urinary anti-H. pylori antibody test was conducted on high school students from 2007 to 2017. Students who tested positive for this examination were recommended secondary screening by esophagogastroduodenoscopy (EGD), with eradication therapy for those with confirmed H. pylori infection. We analyzed data from 2007 to 2011 as the early period and from 2012 to 2017 as the late period.

RESULTS

Over 11 years, 5178 of 5193 (99.7%) subjects received primary screening, among which 184 students (3.6%) tested positive. The primary screening-positive rate decreased significantly from 4.7% in the early period to 2.8% in the late period (p < 0.01). EGD as secondary screening in 103 students (56%) revealed nodular gastritis (83.3%) as the most common endoscopic finding. H. pylori infection was diagnosed in 90 students (87.4%). The resistance rate of H. pylori to clarithromycin was 41.1%. The initial eradication therapy success rate by treatment selection according to H. pylori susceptibility was 96.5%.

CONCLUSIONS

The introduction of H. pylori screening into school health checkups achieved high participation rates and appeared useful for identifying and treating H. pylori infection in young populations.

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.

Seven-Day Vonoprazan-Based Triple Therapy as First-Line Helicobacter pylori Treatment in Comparison With Extended Sequential Therapy: A Randomized Controlled Trial

BACKGROUND

Vonoprazan, a potassium-competitive acid blocker, has demonstrated greater potency and a longer duration of acid suppression when compared to the proton pump inhibitors. However, data regarding the comparison between vonoprazan-based triple therapy with standard treatment for first-line Helicobacter pylori treatment are limited. This study aimed to compare the efficacy between 7-day vonoprazan-based triple therapy with high-dose amoxicillin (VAC-7) and 14-day extended sequential therapy (S-14).

MATERIALS AND METHODS

This was a single-center prospective randomized controlled trial following a noninferiority design. Subjects over 20 years old with confirmed H. pylori infection were enrolled prospectively from Fu Jen Catholic University Hospital. They were randomly assigned to the VAC-7 or S-14 group. The primary endpoint was the eradication rate in first-line treatment, evaluated by urea breath test, with noninferiority determined using the Farrington-Manning method. The secondary outcome included adverse effect rates and compliance, assessed through self-administered questionnaires.

RESULTS

Between December 2021 and June 2023, a total of 628 patients were recruited. The eradication rates by per-protocol analysis and intention-to-treat analysis were 88.6%/81.8% for VAC-7 and 90.3%/81.4% for S-14, respectively. The VAC-7 was non-inferior to S-14 in terms of ITT analysis. Subjects experienced fewer incidences of nausea, anorexia, dizziness, fatigue, and any severe adverse events in the VAC-7 group. Compliance was higher in the VAC-7 group, with 94% taking all the pills correctly.

CONCLUSIONS

Our findings supported the use of 7-day vonoprazan triple therapy with high-dose amoxicillin as the standard first-line treatment for H. pylori infection.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05371249.

Cost-Effectiveness of Population-Based Helicobacter pylori Screening With Eradication for Optimal Age of Implementation

BACKGROUND

Helicobacter pylori screening with eradication reduces gastric cancer (GC) development. However, it was unknown at what age the H. pylori screening should be implemented to achieve the greatest benefits at the least cost. This study aimed to determine the optimal age of H. pylori screening for primary GC prevention.

MATERIALS AND METHODS

A state transition model for a hypothetical cohort of 15-year-olds from a healthcare payer perspective on a lifetime horizon was developed. Nine ages for H. pylori testing were considered: 15, 18, 20, 30, 40, 50, 60, 70, and 80 years. H. pylori screening was compared with no screening and annual, biennial, and triennial endoscopies starting at age 50. The main outcomes were costs, quality-adjusted life-years (QALYs), life expectancy life-years (LYs), incremental cost-effectiveness ratios, GC cases, stage I GC cases, and GC-related deaths. One-way, two-way, and probabilistic sensitivity analyses were performed to assess the uncertainty of the parameters.

RESULTS

All H. pylori screenings at ages 15-80 were more cost-effective than all endoscopies and no screening. H. pylori screening at age 15 yielded the greatest cost-saving and benefits. The cost-effectiveness was sensitive to the adherence rate of H. pylori screening at age 15. Cost-effectiveness acceptability curves showed that H. pylori screening at age 15 was 99.6% cost-effective at a willingness-to-pay threshold of US$50,000 per QALY gained. Compared with no screening and biennial endoscopy in 15.6 million 15-year-olds from 2022 to 2037, respectively, H. pylori screening at age 15 saves US$9.70 million and US$2.39 billion, increases 1.26 million QALYs with 1312 LYs and 651 LYs, prevents 436 GC cases with 254 stage I GC cases and 305 stage I GC cases, and avoids 176 GC-related deaths and 72 GC-related deaths.

CONCLUSIONS

The optimal age for population-based H. pylori screening at ages 15-80 is the youngest, 15 years old. Shifting population-based H. pylori screening to younger people will reduce GC morbidity and mortality worldwide, along with a detailed investigation of the feasibility and long-term consequences of H. pylori eradication at a young age.

Vonoprazan-amoxicillin dual regimen with Saccharomyces boulardii as a rescue therapy for Helicobacter pylori: Current perspectives and implications

Yu et al's study in the World Journal of Gastroenterology (2023) introduced a novel regimen of Vonoprazan-amoxicillin dual therapy combined with Saccharomyces boulardii (S. boulardii) for the rescue therapy against Helicobacter pylori (H. pylori), a pathogen responsible for peptic ulcers and gastric cancer. Vonoprazan is a potassium-competitive acid blocker renowned for its rapid and long-lasting acid suppression, which is minimally affected by mealtime. Compared to proton pump inhibitors, which bind irreversibly to cysteine residues in the H+/K+-ATPase pump, Vonoprazan competes with the K+ ions, prevents the ions from binding to the pump and blocks acid secretion. Concerns with increasing antibiotic resistance, effects on the gut microbiota, patient compliance, and side effects have led to the advent of a dual regimen for H. pylori. Previous studies suggested that S. boulardii plays a role in stabilizing the gut barrier which improves H. pylori eradication rate. With an acceptable safety profile, the dual-adjunct regimen was effective regardless of prior treatment failure and antibiotic resistance profile, thereby strengthening the applicability in clinical settings. Nonetheless, S. boulardii comes in various formulations and dosages, warranting further exploration into the optimal dosage for supplementation in rescue therapy. Additionally, larger, randomized, double-blinded controlled trials are warranted to confirm these promising results.

Effectiveness of vonoprazan-based regimens compared with proton pump inhibitor-based regimens as first-line Helicobacter pylori agents

In this study, we compared the success rate of eradicating Helicobacter pylori (H. pylori) in adults and children using vonoprazan (VPZ)-based H. pylori regimens to that of proton pump inhibitors (PPIs). In Japan, the success rate of a VPZ-based regimen as first-line therapy was lower in children than in adults. Compared with adults, children around puberty have higher CYP2C19 and CYP3A4 enzymatic activity to metabolize PPIs and VPZ. Further, children generally have shorter intestinal transit times than adults and may absorb antibiotics to a lesser extent. When comparing success rates of pediatric and adult eradication therapy using VPZ, it is very important to maintain a higher intragastric pH with sufficient gastric acid suppression to maintain H. pylori in a replicating state and amoxicillin and clarithromycin in the intestinal tract for as long as possible by reducing diarrhea as a side effect. Based on the above, it is reasonable that VPZ, which can suppress stomach acids more strongly than PPI, is a more relevant H. pylori eradication therapy.

Antibiotic resistance characteristics and risk factors analysis of Helicobacter pylori strains isolated from patients in Liaoning Province, an area in North China

Background

The prevalence of Helicobacter pylori (H. pylori) keeps rising while the eradication rate continues to decline due to the increasing antibiotic resistance. Regional variations of antimicrobial resistance to H. pylori have been recommended by guidelines in recent years. This study aims to investigate the antibiotic resistance rate of H. pylori and its association with infected subjects' characteristics in Liaoning Province, an area in north China.

Methods

Gastric tissues from 178 H. pylori positive participants without previous antibiotic use within four weeks were collected for H. pylori culture. Antibiotic susceptibility to furazolidone (AOZ), tetracycline (TC), levofloxacin (LFX), metronidazole (MET), clarithromycin (CLA), and amoxicillin (AMX) were examined with the agar dilution method. Associations between H. pylori resistance and patient characteristics were further analysed.

Results

No resistance was observed in AOZ or TC. For LFX, MET, CLA, and AMX, the overall resistance rates were 41.10%, 79.14%, 71.78%, and 22.09% respectively. There were significant differences between resistance to CLA and MALToma (P = 0.021), and between resistance to MET and age (P < 0.001).

Conclusions

The primary resistant rates of LEX, MET, CLA, and AMX were relatively high in Liaoning. Treatment effectiveness improvement could be achieved by prior antimicrobial susceptibility tests before antibiotic prescription.

Efficacy and safety of vonoprazan-based regimen for Helicobacter pylori eradication therapy in Japanese adolescents: a prospective multicenter study

BACKGROUND

Vonoprazan (VPZ)-based regimen for Helicobacter pylori (H. pylori) is safe and more efficacious than the proton pump inhibitor-based regimen mainly in adults. This study aimed to evaluate the efficacy and safety of a VPZ-based regimen for H. pylori eradication therapy in adolescents.

METHODS

An H. pylori screening and treatment longitudinal project for third-year junior high school students in Saga Prefecture began in 2016. Students who tested positive for both urine and stool tests received a VPZ-based regimen. On the checklist, students were asked for diarrhea, fever, abdominal pain, nausea, vomiting, urticaria, dysgeusia, or bloody stool occurrence during the therapy.

RESULTS

The longitudinal project for H. pylori screening and treatment among third-grade students in Saga Prefecture targeted 41,115 students from 2017 to 2021 and 836 as positive. Of the 645 students, 542 (84.0% in per protocol [PP] analysis and 73.6% in intention-to-treat [ITT] analysis) were successful in primary eradication therapy. The secondary eradication therapy was successful in 79 (96.3% in PP analysis and 76.7% in ITT analysis) of 82 students. In the primary eradication therapy, abdominal pain occurred in 164 (27.9%), diarrhea in 217 (36.9%), nausea or vomiting in 7 (1.2%), and urticaria in 13 (2.2%) students. In the secondary eradication therapy, abdominal pain occurred in 12 (19.4%) and diarrhea in 17 (27.4%) students. The eradication therapy of 5 students was interrupted due to adverse events only by primary eradication therapy.

CONCLUSIONS

VPZ-based regimen for H. pylori was efficacious and safe for adolescents, as in adults, for both primary and secondary eradication therapies.

Development and evaluation of a simple PCR assay and nested PCR for rapid detection of clarithromycin-resistant Helicobacter pylori from culture and directly from the biopsy samples in India

BACKGROUND

Eradication of Helicobacter pylori provides the most effective treatment for gastroduodenal diseases caused by H. pylori infection. Clarithromycin, a member of the macrolide family, still remains the most important antibiotic used in H. pylori eradication treatment. But the increasing prevalence of clarithromycin resistant H. pylori strains due to point mutations in the V region of the 23S rRNA, poses a great threat in treating the ailing patients. So, we aimed for PCR-mediated rapid detection of the point mutation at 2143 position of 23S rRNA gene in H. pylori that is relevant to clarithromycin resistance from culture and simultaneously from biopsy specimens to avoid the empirical treatment.

RESULTS

Newly developed PCR assay using DNA of pure culture detected point mutation in 23S rRNA gene in 21 (8.04%) of 261 clinical strains tested. The agar dilution method showed that all these 21 strains were resistant to clarithromycin indicating the perfect match of the PCR based results. Additionally, the sequencing study also identified the A to G mutation at 2143 position in 23S rRNA gene of the resistant strains only. Consequently, the newly developed Nested-ASP-PCR dealing directly with 50 biopsy specimens demonstrated 100% sensitivity and specificity with the findings of agar dilution method taken as Gold standard. Bioinformatics based analysis such as accessibility analysis and dot plot clearly stated that the base pairing probability has increased due to mutation. Computational studies revealed that the point mutation confers more stability in secondary structure due to conversion of loop to stem. Furthermore, interaction studies showed binding affinity of the CLR to the mutant type is weaker than that to the wild type.

CONCLUSION

This assay outlines a rapid, sensitive and simple approach to identify point mutation that confers clarithromycin resistance as well as clarithromycin sensitive strains, providing rapid initiation of effective antibiotic treatment. Additionally, it is simple to adopt for hospital based diagnostic laboratories to evaluate the degree of regional clarithromycin resistance from biopsy specimens itself. Furthermore, in silico studies provide evidence or a signal that the prevalence of clarithromycin resistance may rise in the near future as a result of this point mutation.

Current guidelines for Helicobacter pylori treatment in East Asia 2022: Differences among China, Japan, and South Korea

Helicobacter pylori (H. pylori) infection is highly prevalent in East Asia. The overall seroprevalence rate of H. pylori infection is 44.2% in China, 37.6%-43.2% in Japan, and 51.0% in South Korea. H. pylori can cause peptic ulcer disease and gastric cancer. East Asian countries have high rates of gastric cancer (age-standardized incidence rate: 20-30 per 100000). The Kyoto global consensus report emphasized that H. pylori gastritis should be considered the main cause for the development of gastric cancer. H. pylori treatment guidelines in China, Japan, and South Korea have recently been revised according to data from each of those countries. However, emerging antibiotic resistance is an important barrier to H. pylori eradication. The recommended H. pylori treatment regimens differ among those three East Asian countries. In this review, recent guidelines and up-to-date research on H. pylori treatment regimens from China, Japan, and South Korea are discussed.

Eradication therapy for Helicobacter pylori infection based on the antimicrobial susceptibility test in children: A single-center study over 12 years

BACKGROUND

Helicobacter pylori (H. pylori) infection causes chronic gastritis, duodenal and to a lesser extent, gastric ulcers, and gastric cancer. Most H. pylori infections are acquired in childhood, and effective treatment of childhood infection is very important. Esophagogastroduodenoscopy (EGD) is useful for endoscopic diagnosis, mucosal tissue biopsy, and culture examination for H. pylori in children and adults. In this paper, we report results of susceptibility tests and eradication rates in H. pylori-positive children who underwent EGD over a 12-year period.

MATERIALS AND METHODS

The subjects were H. pylori-positive pediatric patients who had gastrointestinal symptoms and underwent EGD in the Department of Pediatrics, Juntendo University Hospital (January 2007-December 2018). Patients underwent serum IgG antibody tests, fecal antigen tests, or urea breath tests, and subsequently, culture tests by gastric mucosal biopsy during EGD. H. pylori positivity was defined as a positive result on both tests. Patients received triple therapy for 14 days using our regimen, and eradication was assessed at 2, 6, and 12 months after therapy.

RESULTS

Forty-five patients were H. pylori-positive, and the overall clarithromycin (CAM) resistance rate was 71.1 % (32/45). The CAM resistance rate for the 2013-2018 period was significantly higher than the 2007-2012 period (52.6% vs. 84.6%, P < 0.05). According to the results of the antimicrobial susceptibility test, we prescribed effective antibiotics, and this resulted in a primary eradication rate of 97.7%.

CONCLUSIONS

We suggest that antimicrobial susceptibility testing can significantly improve rates of primary eradication of H. pylori infection.

Polymerase chain reaction-based tests for detecting Helicobacter pylori clarithromycin resistance in stool samples: A meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infection is closely associated with the etiology of a variety of gastric diseases. The effective eradication of H. pylori infection has been shown to reduce the incidence of gastric carcinoma. However, the rate of H. pylori eradication has significantly declined due to its increasing resistance to antibiotics, especially to clarithromycin. Therefore, the detection of clarithromycin resistance is necessary prior to the treatment of H. pylori. Although many studies have been conducted on the use of polymerase chain reaction (PCR)-based tests to detect clarithromycin resistance in stool samples, no accurate data on the feasibility of these tests are available. Here, we performed a meta-analysis to assess the feasibility of these noninvasive tests.

AIM

To evaluate the reliability of PCR-based tests for detecting H. pylori clarithromycin resistance in stool samples.

METHODS

We searched PubMed, Medline, Embase, and other databases for articles that evaluated the value of the PCR analysis of stool samples for detecting the resistance of H. pylori to clarithromycin. We collected cross-sectional studies that met the inclusion criteria. Diagnostic accuracy measures were pooled using a random-effects model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Subgroup analysis was also conducted according to PCR type, purification technique, reference standard, mutation site, sample weight, number of patients, and age group, and the clinical utility of diagnostic tests was evaluated using the Likelihood Ratio Scatter Graph.

RESULTS

Out of the 1818 identified studies, only 11 met the eligibility criteria, with a total of 592 patients assessed. A meta-analysis of the random-effect model showed that PCR-based analysis of stool samples had high diagnostic accuracy for detecting clarithromycin resistance in patients infected with H. pylori. The combined sensitivity was 0.91 [95% confidence interval (CI): 0.83-0.95], Q = 30.34, and I² = 67.04, and the combined specificity was 0.97 (95%CI: 0.62-1.00), Q = 279.54, and I² = 96.42. The likelihood ratio for a positive test was 33.25 (95%CI: 1.69-652.77), and that for a negative test was 0.10 (95%CI: 0.05-0.18), with an area under the curve of 0.94. The diagnostic odds ratio was 347.68 (95%CI: 17.29-6991.26). There was significant statistical heterogeneity, and the sub-analyses showed significant differences in the number of patients, sample weight, purification methods, PCR types, mutation points, and reference standards. The included studies showed no risk of publication bias.

CONCLUSION

PCR-based tests on stool samples have high diagnostic accuracy for detecting H. pylori clarithromycin resistance.

The updated JSPGHAN guidelines for the management of Helicobacter pylori infection in childhood

The Japan Pediatric Helicobacter pylori Study Group published the first guidelines on childhood H. pylori infection in 1997. They were later revised by the Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition (JSPGHAN). The H. pylori eradication rates, when employing triple therapy with amoxicillin and clarithromycin, currently recommended as the first-line therapy of H. pylori infection in Japan, have substantially decreased, creating an important clinical problem worldwide. In Japanese adults, the "test-and-treat" strategy for H. pylori infection is under consideration as an approach for gastric cancer prevention. However, the combined North American and European pediatric guidelines have rejected such a strategy for asymptomatic children. As risk for gastric cancer development is high in Japan, determining whether the "test-and-treat" strategy can be recommended in children has become an urgent matter. Accordingly, the JSPGHAN has produced a second revision of the H. pylori guidelines, which includes discussion about the issues mentioned above. They consist of 19 clinical questions and 34 statements. An H. pylori culture from gastric biopsies is recommended, not only as a diagnostic test for active infection but for antimicrobial susceptibility testing to optimize eradication therapy. Based upon antimicrobial susceptibility testing of H. pylori strains (especially involving clarithromycin), an eradication regimen including use of the antibiotics to which H. pylori is susceptible is recommended as the first-line therapy against H. pylori-associated diseases. The guidelines recommend against a "test-and-treat" strategy for H. pylori infection for asymptomatic children to protect against the development of gastric cancer because there has been no evidence supporting this strategy.

Assessment of a novel method to detect clarithromycin-resistant Helicobacter pylori using a stool antigen test reagent

BACKGROUND

The resistance rate of Helicobacter pylori to clarithromycin (CAM) is high among infected children in Japan. Therefore, a new method for detecting CAM-resistant H. pylori using a minimally invasive technique is strongly desired. We aimed to investigate the clinical usefulness of our newly developed nested polymerase chain reaction-quenching probe (Nested PCR-QP) method using stool specimens.

METHODS

We first evaluated our method using a residual solution of the H. pylori stool antigen test for adolescents. Then, we evaluated our method using culture testing for adults.

RESULTS

Among 57 middle school students with H. pylori, the Nested PCR-QP test results of 53 (90.3%) were able to be analyzed. A total of 28 students had CAM resistance mutations. We found a genetic mutation in 28 students and no mutation in 23 students, and these results were consistent with those of PCR-direct sequencing. In the 23 adults who were diagnosed with H. pylori infection using the rapid urease test and culture testing, we were able to use Nested PCR-QP for analyzing 21 adults who tested positive in the stool H. pylori antigen test. The results obtained for all 21 adults were consistent with those obtained via the drug susceptibility test.

CONCLUSIONS

Our novel method could be useful for non-invasively detecting CAM resistance mutations in H. pylori. This may help select a drug to reduce eradication failure rates against H. pylori. Trial registration This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (no. UMIN000030632, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034977 ) on 29 December 2017.

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.

The Potential Benefits of Vonoprazan as Helicobacter pylori Infection Therapy

Helicobacter pylori infection is a severe global health problem that is closely associated with acid-related diseases and gastric malignancies. Eradicating H. pylori is strongly recommended for lowering peptic ulcer recurrence and preventing gastric cancer. The current approved H. pylori eradication regimen combines a proton pump inhibitor (PPI) with two antibiotics. Unfortunately, this regimen failed to meet expectations mostly due to antibiotic resistance and insufficient gastric acid suppression. Vonoprazan, a novel potassium-competitive acid blocker, showed promising results as a PPI replacement. Vonoprazan inhibits gastric acid secretion by acting as a reversible competitive inhibitor against potassium ions and forming disulfide bonds with the cysteine molecule of H⁺/K⁺-ATPase. Vonoprazan has superior pharmacological characteristics over PPI, such as no requirement for acid activation, stability in acidic conditions, shorter optimum acid suppression period, and resistance to cytochrome P (CYP)2C19 polymorphism. Several comparative randomized controlled trials and meta-analyses revealed the superiority of vonoprazan in eradicating H. pylori, notably the resistant strains. The adverse effect caused by vonoprazan is long-term acid suppression that may induce elevated gastrin serum, hypochlorhydria, and malabsorption. All vonoprazan studies have only been conducted in Japan. Further studies outside Japan are necessary for universally conclusive results.

Efficacy of Vonoprazan for Helicobacter pylori Eradication

Helicobacter pylori can infect the gastric mucosa and cause chronic inflammation, resulting in various diseases, including gastric cancer. Eradication of H. pylori in all infected subjects is recommended; however, the number of H. pylori strains with antibiotic resistance has increased, and the eradication rate has decreased. Vonoprazan, a potassium-competitive acid blocker, produces a stronger acid-inhibitory effect than proton pump inhibitors (PPIs). The H. pylori eradication rate with vonoprazan was found to be higher than that with PPIs. The H. pylori eradication rate with vonoprazan-based triple therapy (vonoprazan, amoxicillin, and clarithromycin) was approximately 90% and had an incidence of adverse events similar to that of PPIs. We review the current situation of H. pylori eradication in Japan, the first country in which vonoprazan was made available.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antimicrobial activity of ellagic acid against Helicobacter pylori isolates from India and during infections in mice

Objectives

Because of the rise in antimicrobial resistance, an inexpensive, diet-based treatment against Helicobacter pylori infection would be of great interest. The present study was performed to assess the in vitro effects of ellagic acid against clinical H. pylori strains that were resistant to antibiotics used for therapy and also to observe the morphological structure following treatment with ellagic acid. The effectiveness of ellagic acid in eradicating H. pylori infection in a murine (C57BL/6) infection model, one of the standard inbred mouse lines often used for experimental infection, was also assessed.

Methods

A total of 55 strains were screened. The agar dilution method was used to determine the susceptibility of isolates to test compounds. Transmission electron microscopy was used to observe the morphology following treatment with ellagic acid. The antibacterial activity of ellagic acid in an H. pylori SS1-infected mouse model and its effect on gastric mucosal injury were determined by histology and PCR.

Results

Ellagic acid inhibited the growth of all 55 of the H. pylori strains tested. The MIC of ellagic acid ranged from 5 to 30 mg/L, showing its bactericidal properties in vitro. Ellagic acid also demonstrated anti-H. pylori efficacy in eradication of this organism in an in vivo model, as well as restitution and repair of H. pylori-induced gastric mucosal damage.

Conclusions

The present study paves the way for the preventive and therapeutic use of ellagic acid against H. pylori infection and, thus, ellagic acid can be considered a promising antibacterial agent against H. pylori-associated gastroduodenal diseases in humans.

A Helicobacter pylori screening and treatment program to eliminate gastric cancer among junior high school students in Saga Prefecture: a preliminary report

BACKGROUND

To present the strategies and preliminary findings of the first 3 years after implementing a Helicobacter pylori screening and eradication program to prevent gastric cancer in Saga Prefecture.

METHODS

A screening and treatment program to eradicate H. pylori from third-grade junior high students was started in Saga Prefecture in 2016, using local governmental grants. Screening was with urinary anti-H. pylori antibody tests, followed by H. pylori stool antigen tests for students who were antibody positive. Those positive on both tests underwent H. pylori eradication by triple therapy based on a potassium-competitive acid blocker.

RESULTS

From 2016 to 2018, the participation rate was 83.1% and the H. pylori infection rate was 3.1% (660/21,042). The participation rates were higher in 2017 (85.4%) and 2018 (85.9%) compared with 2016 (78.5%) (P < 0.0001), and the infection rate also decreased in a time-dependent manner (2016: 3.6%, 2017: 3.3%, 2018: 2.5%, P = 0.0001). In total, 501 students positive for H. pylori received eradication therapy (85.1% success) and adverse events occurred in 20 of these (4.0%). However, no serious complications occurred.

CONCLUSIONS

The H. pylori screening and eradication project for school students in Saga Prefecture has started successfully and we have seen both a steady increase in the participation rate and a steady decrease in the infection rate, without major safety concerns.

Current status of first- and second-line Helicobacter pylori eradication therapy in the metropolitan area: a multicenter study with a large number of patients

BACKGROUND

The environment surrounding Helicobacter pylori eradication treatment is dramatically changing. Recently, vonoprazan, a first-in-class potassium-competitive acid blocker (P-CAB), was introduced onto the market in 2015. The aging of Japan's demographic structure is becoming pronounced. In this study, we examined the trend of the eradication rate of H. pylori in the metropolitan area and examined factors concerning successful eradication.

METHODS

We collected data from 20 hospitals in the Tokyo metropolitan area on patients who received first-line eradication therapy with a proton-pump inhibitor (PPI)/P-CAB, amoxicillin, and clarithromycin for 1 week and second-line eradication therapy with a PPI/P-CAB, amoxicillin, and metronidazole for 1 week from 2013 to 2018. The annual eradication rate and associated factors for successful eradication were analyzed.

RESULTS

We collected data of 4097 and 3572 patients in the first- and second-line eradication therapies, respectively. The eradication rate decreased from 2013 to 2014 and increased again from 2015 to 2018 with the first-line therapy [the eradication rates in 2013, 2014, 2015, 2016, 2017 and 2018 were 71.8%, 63.7%, 78.5%, 84.6%, 89.7 and 90.1%, respectively, in the per protocol (PP)]. The second-line eradication rates were 90.0%, 82.6%, 88.8%, 87.5%, 91.8% and 90.1% in 2013, 2014, 2015, 2016, 2017 and 2018, respectively, in PP. Vonoprazan was an independent factor for successful eradication in not only first-line, but also second-line eradication. Age over 75 years was an independent factor for eradication failure in both first- and second-line eradication therapies.

CONCLUSION

The eradication rate improved from 2015 to 2018 with the first-line therapy because of the introduction of vonoprazan in the market. The eradication rates with first- and second-line regimens in elderly patients were lower than those in younger patients.

The antibiotic resistance of Helicobacter pylori to five antibiotics and influencing factors in an area of China with a high risk of gastric cancer

Background

H. pylori exhibits antibiotic resistance with regional differences. In this paper, we explored antibiotic resistance of H. pylori to five antibiotics in an area with a high risk of gastric cancer.

Results

H. pylori resistance rates to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were 78.0, 56.0, 31.0, 9.0, and 15.0%, respectively. Double, triple, quadruple, and quintuple resistance rates were 23, 20, 6, and 4%, respectively. The clarithromycin and multidrug resistance rates were significantly higher in males than females (clarithromycin: 44.4% vs 15.2%, respectively, P = 0.002; multidrug: 75.5% vs 37.2%, respectively; P < 0.001). During the three periods of 1998–1999, 2002–2004 and 2016–2017, the resistance rates to levofloxacin and amoxicillin were increasing (OR: 2.089, 95%CI: 1.142–3.821, P = 0.017; and OR: 5.035, 95%CI: 1.327–19.105, P = 0.018, respectively). The antibiotic resistance rates were unassociated with the host disease state. Metronidazole resistance was lower in the vacAs1m1/m2 group than the vacAs1m1m2 group (65% vs 85.7%, respectively; P = 0.026). As for levofloxacin resistance, it was higher with cagA⁺ than cagA⁻ (60.9% vs 23.1%, respectively; P = 0.020) but lower with slyD⁺ than slyD⁻ (41.4% vs 68.5%, respectively; P = 0.009). Clarithromycin had a lower resistance rate with iceA⁺⁺ than iceA⁻⁺ (19.7% vs 52.4%, respectively; P = 0.017). For amoxicillin, the iceA⁺⁺ group had a lower resistance rate than the iceA⁻⁻ group (1.6% vs 27.8%, respectively; P = 0.009).

Conclusions

The total resistance rates of H. pylori to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were high in Zhuanghe. The resistanc rates to levofloxacin and amoxicillin increased over time. Clarithromycin resistance was associated with male and iceA. The resistance of metronidazole was related to vacA. Levofloxacin resistance was concerned with cagA and slyD and amoxicillin resistance was concerned with iceA. While, the antibiotic resistance of H. pylori had nothing to do with the status of gastric disease.

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.

Evaluation of a Novel Stool Antigen Rapid Test Kit for Detection of Helicobacter pylori Infection

The Quick Chaser H. pylori (QCP), which is a novel antigen detection kit for Helicobacter pylori, was developed recently. The previous examination kits targeted the catalase of H. pylori; however, this new test kit, to the best of our knowledge, is the first kit to target the flagellar protein of H. pylori The present study aimed to evaluate the efficacy of QCP compared with that of the already commercially available rapid test kit Testmate Rapid Pylori Antigen (TRP). TRP and QCP were utilized in 71 participants. The positive and negative concordance ratios of QCP to TRP were 100% (57/57) and 92.9% (13/14), respectively. Sensitivity based on the rapid urease test and culture test was 92.3%. Results of the dilution sensitivity test showed that QCP was eight times more sensitive to an H. pylori standard strain and the clarithromycin (CAM)-resistant clinical isolate and four times more sensitive to a CAM-susceptible clinical isolate than TRP. For the cross-reactivity test, 27 strains that exist in human feces, such as the Helicobacter genus, Bifidobacterium genus, Lactobacillus genus, and other resident bacteria, were selected. The results obtained using QCP were all negative, and no cross-reaction was observed. In conclusion, compared with TRP, QCP can detect H. pylori using clinical specimens with high sensitivity, regardless of CAM susceptibility and tolerance. No cross-reactivity was observed with other intestinal bacteria in humans. The kit is considered extremely useful in clinical settings.

Vonoprazan, a Novel Potassium-Competitive Acid Blocker, Should Be Used for the Helicobacter pylori Eradication Therapy as First Choice: A Large Sample Study of Vonoprazan in Real World Compared with Our Randomized Control Trial Using Second-Generation Proton Pump Inhibitors for Helicobacter pylori Eradication Therapy

BACKGROUND/AIMS

Phase III study demonstrated that vonoprazan-based Helicobacter pylori eradication therapy achieved higher eradication rate compared with lansoprazole. However, there is no study that evaluated the efficacy of vonoprazan in a large sample in real world. We investigated the eradication rate and safety of vonoprazan-based eradication therapy compared with our randomized control trial using second-generation proton pump inhibitor (PPIs).

METHODS

(First study) A total of 147 patients who have H. pylori infection were randomly assigned to receive either, esomeprazole (EPZ) group and rabeprazole (RPZ) group. (Second study) 1,688 patients who have H. pylori infection underwent primary eradication with triple therapy involving vonoprazan. In both studies, triple therapy with amoxicillin, clarithromycin, and PPI or vonoprazan was performed, and eradication effect was assessed by an urea breath test.

RESULTS

(First study) Eradication rate was 77.5% in the EPZ group and 68.4% in the RPZ group; no significant difference was observed between the 2 groups. (Second study) The successful primary eradication rate was 90.8%. There was no severe adverse effect.

CONCLUSIONS

The eradication rate of vonoprazan-based triple therapy was remarkably higher compared with second-generation PPIs-based triple therapy in real world. Vonoprazan is very likely to become the first option for future eradication therapy.

Second-line triple therapy in failures with vonoprazan-based triple therapy for eradication of Helicobacter pylori

Gastric acid inhibition during treatment is important for the eradication of Helicobacter pylori (H. pylori) infection. A novel potassium-competitive acid blocker, vonoprazan (VPZ), has been demonstrated to achieve high eradication rates; however, the efficacy of second-line treatment in failures of VPZ-based triple therapy has not been well studied. The aim of the current study was to determine the efficacy of VPZ in a first-line regimen for H. pylori eradication, and the efficacy of a second-line regimen using metronidazole (MTZ) in failures with the first-line regimen. Of 580 subjects enrolled in the study, 524 patients completed first-line treatment (275 patients who received VPZ and 249 patients who received LPZ). First-line regimens consisted of a combination of clarithromycin (CAM) 200 or 400 mg twice a day, amoxicillin (AMPC) 750 mg twice a day, and either LPZ 30 mg or VPZ 20 mg twice a day, administered orally for 7 days. CAM and VPZ/LPZ were replaced with metronidazole (MTZ) 250 mg and rabeprazole 10 mg in the second-line regimens. The eradication of H. pylori was assessed by the H. pylori stool antigen test. The overall first-line eradication rate with VPZ was significantly higher than that with LPZ [91.0% (250/275) vs. 84.7% (211/249), respectively, P=0.030]. The dose of CAM (400 vs. 800 mg) did not affect the eradication rate in either the VPZ or LPZ regimens. The overall eradication rates of the second-line regimens with MTZ did not differ significantly between the VPZ-failure and LPZ-failure groups [87.0% (20/23) vs. 87.9% (29/33), respectively, P=0.700]. Therefore, VPZ was significantly more effective than LPZ for first-line treatment. In patients with failure of first-line eradication therapy, successful results of second-line eradication therapy did not differ between the VPZ- and LPZ-failure groups. In conclusion, VPZ-based triple therapy should be recommended for eradication of H. pylori.

First-line antibiotic therapy in Helicobacter pylori-negative low-grade gastric mucosa-associated lymphoid tissue lymphoma

First-line antibiotic treatment for eradicating Helicobacter pylori (HP) infection is effective in HP-positive low-grade gastric mucosa-associated lymphoid tissue lymphoma (MALToma), but its role in HP-negative cases is uncertain. In this exploratory retrospective study, we assessed the outcome and potential predictive biomarkers for 25 patients with HP-negative localized gastric MALToma who received first-line HP eradication (HPE) therapy. An HP-negative status was defined as negative results on histology, rapid urease test, 13C urea breath test, and serology. We observed an antibiotic response (complete remission [CR], number = 8; partial remission, number = 1) in 9 (36.0%) out of 25 patients. A t(11;18)(q21;q21) translocation was detected in 7 (43.8%) of 16 antibiotic-unresponsive cases, but in none of the 9 antibiotic-responsive cases (P = 0.027). Nuclear BCL10 expression was significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (14/16 [87.5%] vs. 1/9 [11.1%]; P = 0.001). Nuclear NF-κB expression was also significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (12/16 [75.0%] vs. 1/9 [11.1%]; P = 0.004). A substantial portion of patients with HP-negative gastric MALToma responded to first-line HPE. In addition to t(11;18)(q21;q21), BCL10 and NF-κB are useful immunohistochemical biomarkers to predict antibiotic-unresponsive status in this group of tumors.

Usefulness of detection of clarithromycin-resistant Helicobacter pylori from fecal specimens for young adults treated with eradication therapy

BACKGROUND

To prevent Helicobacter pylori infection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori.

OBJECTIVE

The aim of this study was to evaluate the method of PCR-based sequencing to detect clarithromycin (CAM) resistance-associated mutations using fecal samples as a noninvasive method.

METHODS

DNA extracted from fecal specimens and isolates from gastric biopsy specimens were collected from patients with H. pylori infection. Antibiotic resistance to CAM was analyzed by molecular and culture methods. The detection rates of CAM resistance-associated mutations (A2142C or A2143G) were compared before and after eradication therapy.

RESULTS

With CAM resistance of H. pylori evaluated by antibiotic susceptibility test as a gold standard, the sensitivity and the specificity of gene mutation detection from fecal DNA were 80% and 84.8%, respectively. In contrast, using DNA of isolated strains, the sensitivity and the specificity were 80% and 100%. Of the seven cases in which eradication was unsuccessful by triple therapy including CAM, CAM-resistant H. pylori, and resistance-associated mutations were detected in three cases, CAM-resistant H. pylori without the mutation was detected in two patients, and resistance-associated mutation was only detected in one patient.

CONCLUSION

PCR-based sequencing to detect CAM resistance-associated mutations using isolates or fecal samples was useful for finding antibiotic-resistant H. pylori infection. Although the specificity of the detection from fecal samples compared with antibiotic susceptibility testing was lower than that from isolates, this fecal detection method is suitable especially for asymptomatic subjects including children. Further improvement is needed before clinical application.

Novel and Effective Therapeutic Regimens for Helicobacter pylori in an Era of Increasing Antibiotic Resistance

Helicobacter pylori (H. pylori) is a common gastrointestinal bacterial strain closely associated with the incidence of chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. A current research and clinical challenge is the increased rate of antibiotic resistance in H. pylori, which has led to a decreased H. pylori eradication rate. In this article, we review recent H. pylori infection and reinfection rates and H. pylori resistance to antibiotics, and we discuss the pertinent treatments. A PubMed literature search was performed using the following keywords: Helicobacter pylori, infection, reinfection, antibiotic resistance, bismuth, proton pump inhibitors, vonoprazan, susceptibility, quintuple therapy, dual therapy, and probiotic. The prevalence of H. pylori has remained high in some areas despite the decreasing trend of H. pylori prevalence observed over time. Additionally, the H. pylori reinfection rate has varied in different countries due to socioeconomic and hygienic conditions. Helicobacter pylori monoresistance to clarithromycin, metronidazole or levofloxacin was common in most countries. However, the prevalence of amoxicillin and tetracycline resistance has remained low. Because H. pylori infection and reinfection present serious challenges and because H. pylori resistance to clarithromycin, metronidazole or levofloxacin remains high in most countries, the selection of an efficient regimen to eradicate H. pylori is critical. Currently, bismuth-containing quadruple therapies still achieve high eradication rates. Moreover, susceptibility-based therapies are alternatives because they may avoid the use of unnecessary antibiotics. Novel regimens, e.g., vonoprazan-containing triple therapies, quintuple therapies, high-dose dual therapies, and standard triple therapies with probiotics, require further studies concerning their efficiency and safety for treating H. pylori.

Primary Antibiotic Resistance of Helicobacter pylori in China

BACKGROUND AND AIMS

Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China.

METHODS

We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed.

RESULTS

Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively.

CONCLUSIONS

In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

Effects of patient age and choice of antisecretory agent on success of eradication therapy for Helicobacter pylori infection

The effects of patient age on the efficacy of eradication treatment for Helicobacter pylori (H. pylori) remain unclear. The present study aimed to determine whether age affects eradication therapy involving vonoprazan, a novel potassium-competitive acid blocker (PCAB). We reviewed the cases of 3,261 patients who were administered first-line and second-line H. pylori eradication therapy at Toyoshima Endoscopy Clinic. The first-line treatment was clarithromycin and amoxicillin combined with a proton pump inhibitor (PPI) or a PCAB. The second-line treatment was metronidazole and amoxicillin combined with a PPI or PCAB. The patients were divided into a young to middle-aged group (age ≤50 years) and an older group (age >50 years) as well as into PPI and PCAB groups. The PPI-clarithromycin-amoxicillin regimen demonstrated a significantly lower H. pylori eradication rate than the PCAB-clarithromycin-amoxicillin regimen (p<0.001). With the PPI-clarithromycin-amoxicillin regimen, the eradication rate in the young to middle-aged group was significantly lower than that in the older group (p<0.001). Lastly, age had no impact on the eradication rate of PCAB-based therapy or metronidazole-based therapy. In conclusion, with clarithromycin-based triple therapy, PCAB is a better choice of antisecretory agent compared to PPIs, especially in young to middle-aged patients.

Cost-Effectiveness Analysis of Helicobacter pylori Diagnostic Methods in Patients with Atrophic Gastritis

Background. There are several diagnostic methods for Helicobacter pylori (H. pylori) infection. A cost-effective analysis is needed to decide on the optimal diagnostic method. The aim of this study was to determine a cost-effective diagnostic method in patients with atrophic gastritis (AG). Methods. A decision-analysis model including seven diagnostic methods was constructed for patients with AG diagnosed by esophagogastroduodenoscopy. Expected values of cost and effectiveness were calculated for each test. Results. If the prevalence of H. pylori in the patients with AG is 85% and CAM-resistant H. pylori is 30%, histology, stool H. pylori antigen (SHPAg), bacterial culture (BC), and urine H. pylori antibody (UHPAb) were dominated by serum H. pylori IgG antibody (SHPAb), rapid urease test (RUT), and urea breath test (UBT). Among three undominated methods, the incremental cost-effective ratios (ICER) of RUT versus SHPAb and UBT versus RUT were $214 and $1914, respectively. If the prevalence of CAM-sensitive H. pylori was less than 55%, BC was not dominated, but its H. pylori eradication success rate was 0.86. Conclusions. RUT was the most cost-effective at the current prevalence of CAM-resistant H. pylori. BC could not be selected due to its poor effectiveness even if CAM-resistant H. pylori was more than 45%.

Managing Helicobacter pylori in college health, with special considerations for international students

OBJECTIVE

Helicobacter pylori infection is the major cause of dyspepsia, peptic ulcer disease, and gastric cancer. This paper will make specific recommendations for a diagnostic and treatment strategy tailored to the international student population.

PARTICIPANTS/METHODS

This paper is a case report and narrative review based on recent international epidemiologic studies and consensus conference recommendations identified in MEDLINE.

RESULTS

In the nations (mostly Asian) that send the largest number of students to the United States, the prevalence of H. pylori is generally 60% to 80%, whereas the prevalence in the United States is about 25%. The patterns of antibiotic resistance in those countries are also different than that in the general US population.

CONCLUSIONS

Health care providers should have a higher index of suspicion for Helicobacter infection among international students with dyspepsia and need to use a different treatment regimen than is standard for the general US population.

The Association of Age and Antibiotic Resistance of Helicobacter Pylori: A Study in Jiaxing City, Zhejiang Province, China

The antibiotic resistance of Helicobacter pylori (H pylori) is steadily increasing worldwide, resulting in the low efficiency of the current therapeutic approaches for eradication. In this study, we investigated the relationship between antibiotic resistances, the year of sample collection, and the ages of the infected individuals.A total of 29,034 gastric mucosa biopsy samples were randomly collected from January 1, 2009 to December 9, 2014 in Jiaxing City, Zhejiang Province, China. An antibiotic susceptibility testing was determined using an agar-dilution method. The statistical significance was tested using the chi-squared (χ) test.A total of 9687 strains were isolated. The resistance rate to clarithromycin, levofloxacin, and metronidazole were 17.76%, 19.66%, and 95.5%, respectively. Resistance was rare against amoxicillin, gentamicin, and furazolidone. The metronidazole resistance rate stayed at a consistently high level. In contrast, the resistance rates of clarithromycin and levofloxacin increased rapidly from 2009 to 2011, gradually decreased from 2012 to 2013, and then increased again in 2014. Although patients ages 31 to 50 and 71 to 80 years had lower infection rates of H pylori, they also had higher resistance rates to clarithromycin and levofloxacin. The highest antibiotic resistance rate was observed in patients' ages 71 to 80 years old. Younger patients (below 30 years old) had a lower resistance to levofloxacin. Patients' ages 51 to 60 years old may thus represent an important category for the future study of H pylori infection.Age plays a key element in H pylori resistance to clarithromycin and levofloxacin. It is therefore necessary to consider individualized therapy for the optimized treatment of H pylori-infected patients.

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.

Helicobacter pylori Antibody Titer and Gastric Cancer Screening

The "ABC method" is a serum gastric cancer screening method, and the subjects were divided based on H. pylori serology and atrophic gastritis as detected by serum pepsinogen (PG): Group A [H. pylori (-) PG (-)], Group B [H. pylori (+) PG (-)], Group C [H. pylori (+) PG (+)], and Group D [H. pylori (-) PG (+)]. The risk of gastric cancer is highest in Group D, followed by Groups C, B, and A. Groups B, C, and D are advised to undergo endoscopy, and the recommended surveillance is every three years, every two years, and annually, respectively. In this report, the reported results with respect to further risk stratification by anti-H. pylori antibody titer in each subgroup are reviewed: (1) high-negative antibody titer subjects in Group A, representing posteradicated individuals with high risk for intestinal-type cancer; (2) high-positive antibody titer subjects in Group B, representing active inflammation with high risk for diffuse-type cancer; and (3) low-positive antibody titer subjects in Group C, representing advanced atrophy with increased risk for intestinal-type cancer. In these subjects, careful follow-up with intervals of surveillance of every three years in (1), every two years in (2), and annually in (3) should be considered.

Prevalence of antibiotic resistance in Helicobacter pylori: A recent literature review

AIM

To review previous studies (the last 6 years) about the Helicobacter pylori (H. pylori) antibiotic resistance in order to evaluate the trend in antibiotic resistance.

METHODS

In this study, the PubMed, MEDLINE, Science Direct, Google Scholar and Scielo manuscripts were reviewed from 2009 to 2014.

RESULTS

On the whole rates of H. pylori antibiotic resistance were 47.22% (30.5%-75.02%) for metronidazole, 19.74% (5.46%-30.8%) for clarithromycin, 18.94% (14.19%-25.28%) for levofloxacin, and 14.67% (2%-40.87%) for amoxicillin, 11.70% (0%-50%) for tetracycline, 11.5% (0%-23%) for furazolidon and 6.75% (1%-12.45%) for rifabutin. The frequency of tetracycline, metronidazole and amoxicillin resistance was higher in Africa, while clarithromycin and levofloxacin resistance was higher in North America and Asian, respectively.

CONCLUSION

The most sensitive drug is rifabutin and the lowest sensitive drug is metronidazole in the world. The worldwide H. pylori antibiotic resistance to clarithromycin and levofloxacin has increased during the last 6 years. The present systematic review show alarming results and a novel plan is needed for eradication therapy of H. pylori infections.

Treatment of Helicobacter pylori Infection 2015

Many interesting articles have been published from many parts of the world over the last year assessing different issues around Helicobacter pylori eradication therapy. This article will address the published literature over the last year pertaining to the topic of treatment of H. pylori infection. The main themes that emerge are assessing the efficacy of standard triple therapy, as well as exploring new first-line treatments, mainly optimized nonbismuth- and bismuth-containing quadruple therapies with some promising data also emerging on dual therapy. There was also considerable progress in investigating antibiotic resistance rates with much more data emerging from varied parts of the world compared to recent years. There have also been advances in the use of adjunctive therapies, especially probiotic therapies. Undoubtedly, the eradication of H. pylori remains a worthwhile goal to alleviate the burden of diseases caused by the complications of this infection, including dyspepsia, peptic ulcer disease, and gastric cancer.

Helicobacter pylori Infection in Pediatrics

This review includes the main pediatric studies published from April 2014 to March 2015. The host response of Treg cells with increases in FOXP3 and TGF-β1 combined with a reduction in IFN-γ by Teff cells may contribute to Helicobacter pylori susceptibility in children. Genotypic variability in H. pylori strains influences the clinical manifestation of the infection. Helicobacter pylori infection is associated with variables indicative of a crowded environment and poor living conditions, while breast-feeding has a protective effect. Intrafamilial infection, especially from mother to children and from sibling to sibling, is the dominant transmission route. Studies showed conflicting results regarding the association between H. pylori infection and iron deficiency anemia. One study suggests that H. pylori eradication plays a role in the management of chronic immune thrombocytopenic purpura in H. pylori-infected children and adolescents. The prevalence of H. pylori was higher in chronic urticaria patients than in controls and, following H. pylori eradication, urticarial symptoms disappeared. An inverse relationship between H. pylori infection and allergic disease was reported. Antibiotic resistance and insufficient compliance to treatment limit the efficacy of eradication therapy. Sequential therapy had no advantage over standard triple therapy. In countries where H. pylori infection is prevalent, studies focusing on virulence factors and antibiotic susceptibility may provide anticipation of the prognosis and may be helpful to reduce morbidity and mortality.

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.