Roles of the components of the cag-pathogenicity island encoded type IV secretion system in Helicobacter pylori.

The Helicobacter pylori (H. pylori) cytotoxin-associated gene pathogenicity island (cagPAI) encodes 31 genes that assemble the cag type IV secretion system (T4SS) apparatus, which includes structures such as the outer membrane core complex, periplasmic ring, inner membrane complex and bacterial hairs. These proteins interact with each other to inject CagA into the host gastric epithelium. There are also individual unique functions that help H. pylori interfere with host cellular pathways, modulate the immune response and colonize the host for a long time. However, the functions of some of the proteins remain unclear. This review summarizes what is known about the structure and function of these auxiliary components and discusses their role in H. pylori pathogenesis.

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High-dose amoxicillin-proton pump inhibitor dual therapy as first-line treatment for Helicobacter pylori infection in Northwest China: A prospective, randomised controlled trial.

AIMS: We aimed to assess the eradication efficacy and factors that influencing it of high-dose dual therapy (HDDT) in Gansu region, Northwest China. METHODS: A total of 216 treatment-naive patients with Helicobacter pylori infection were randomly assigned to two groups for the 14-day eradication treatment: the HDDT group (amoxicillin 750 mg q.i.d. and esomeprazole 40 mg t.i.d.) and the amoxicillin and clarithromycin-containing bismuth quadruple therapy group (ACBQT: esomeprazole 20 mg, bismuth potassium citrate 2 g, amoxicillin 1 g, and clarithromycin 500 mg; b.i.d.). The eradication rates, adverse effects and patient compliance of these two groups were compared. Eradication efficacy was determined by 13 C urea breath test (13 C UBT) 4-8 weeks after finishing treatment. Antibiotic resistance was determined by the Epsilometer testing (E-test) method. RESULTS: The eradication rates for the HDDT and ACBQT groups were 71.0% and 74.7% (P = .552) by per-protocol analysis, and 65.7% and 68.5% (P = .664) by intention-to-treat analysis. The overall adverse event rates in the HDDT and ACBQT groups were 2.0% and 43.4% (P < .001), respectively. The resistance rates to amoxicillin, clarithromycin, tetracycline, levofloxacin and metronidazole were 15.2%, 42.0%, 5.4%, 35.7% and 83.0%, respectively. Amoxicillin resistance and delta over baseline (DOB) of 13 C UBT ≥ 20 before treatment significantly reduced the eradication rate in 112 participants with H. pylori cultured. CONCLUSION: The HDDT as first-line treatment for H. pylori was unsatisfactory in Gansu. Amoxicillin resistance and DOB of 13 C UBT ≥ 20 before treatment were significantly correlated with H. pylori eradication failure.

The efficacy of vonoprazan combined with different dose amoxicillin on eradication of Helicobacter pylori: an open, multicenter, randomized clinical study.

Background: The use of vonoprazan (VPZ) has improved the Helicobacter pylori (H. pylori) eradication therapy in Japan. There is no agreement on the dosage and frequency of amoxicillin administration in the VPZ dual treatment in China. We aimed to investigate the clinical effectiveness and safety of 3 treatment regimens using VPZ as an acid-suppressing medication to eradicate H. pylori. Methods: This experiment involved an open, multicenter, randomized, and parallel controlled clinical investigation. A total of 230 newly diagnosed H. pylori-infected patients were then randomly assigned to 1 of 3 groups: (I) H-VA (high-dose amoxicillin combined with VPZ): VPZ 20 mg b.i.d with amoxicillin 750 mg q.i.d for 7 days; (II) L-VA (low-dose amoxicillin combined with VPZ): VPZ 20 mg b.i.d plus amoxicillin 500 mg q.i.d for 7 days; (III) VAC (amoxicillin combined with VPZ and clarithromycin): VPZ 20 mg b.i.d plus amoxicillin 750 mg plus clarithromycin 500 mg for 7 days. At least 4 weeks after treatment, the urea breath test (UBT) was reexamined. The effectiveness of various regimens was assessed based on compliance, safety, and eradication rate. Results: The regimen effectiveness was 63.5% (54/85) in the H-VA group, 58.3% (49/84) in the L-VA group, and 60.7% (37/61) in the VAC group, according to intention to treat (ITT) analysis. According to per protocol (PP) analysis, the eradication rate of the H-VA group was 65.1% (54/83), that of the L-VA group was 66.2% (49/74), and that of the VAC group was 64.9% (37/57). There was no discernible difference in the eradication rate across the 3 regimens, as shown by the results of ITT analysis (χ2=0.032, P=0.984) and PP analysis (χ2=0.480, P=0.786). The rate of adverse effect was 16.90% in the H-VA group, 13.20% in the L-VA group, and 24.10% in the VAC group. There was no discernible difference in the incidence of adverse effect between the three groups (χ2=2.784, P=0.266). Conclusions: None of the 7-day elimination regimens investigated in this study, which included the acid-suppressing medicine VPZ and either a dual treatment paired with amoxicillin, or a triple treatment combined with amoxicillin and clarithromycin, achieved an acceptable eradication rate of H. pylori. Further research is required to identify an effective and safe treatment regimen. Trial Registration: Chinese Clinical Trial Registry identifier: ChiCTR2000040955.

Antibiotics Resistance Prevalence of Helicobacter pylori Strains in Northwest China.

Purpose: This study aims to estimate the resistance rate of Helicobacter pylori (HP) to commonly used antibiotics and analyze the potential influencing factors in northwest regions of China. Patients and Methods: HP-positive patients visiting the outpatient department of multiple hospitals were enrolled in the study. Then, gastric mucosal biopsy specimens were collected for HP isolation, culture, and investigation of the resistance rate of HP to amoxicillin, metronidazole, tetracycline, levofloxacin, and clarithromycin by Epsilometer test (E-test) antibiotic susceptibility testing. In addition, multi-drug resistance, the influence of HP eradication history, age, and region of residence on drug resistance rate were analyzed. Results: In total, 198 HP clinical strains were successfully isolated and cultured. The resistance rates of amoxicillin, metronidazole, tetracycline, levofloxacin, and clarithromycin were 16.16%, 85.86%, 7.58%, 46.46%, and 55.05%, respectively. The multi-drug resistance rates demonstrated that dual and triple resistances were 30.30% and 22.73%, respectively. The quadruple resistance rate reached 9.60%. Our results revealed that the prior eradication history of HP significantly increased levofloxacin and clarithromycin resistance. Metronidazole and levofloxacin resistances significantly differed among different age groups, which presented an upward trend with increasing age. Drug resistance rates varied with geographic regions, especially amoxicillin and clarithromycin resistance, which were highest in Hexi Corridor and Longnan regions. Conclusion: The current situation of HP resistance to common antibiotics is severe. Tetracycline is the most sensitive antibiotic, followed by amoxicillin, the first choice for HP eradication. However, the eradication failure of HP may lead to an increase in the resistance rate. Therefore, it is necessary to strengthen the standardized diagnosis and treatment of HP to improve the primary eradication rate.

The high-dose amoxicillin-proton pump inhibitor dual therapy in eradication of Helicobacter pylori infection.

INTRODUCTION: More attention has been paid to the eradication therapy of Helicobactor pylori with the enhancement of health awareness of patients. However, the increasing antibiotic resistance of H. pylori, due to the wide use and abuse of antibiotics, has become a critical factor affecting the efficacy of eradication. To effectively improve the eradication rate of H. pylori, high-dose amoxicillin-proton pump inhibitor (PPI) dual therapy has recently become one of the hot issues. AREAS COVERED: The authors review the schemes and efficacy of high-dose amoxicillin-PPI dual therapies in eradication of H. pylori infection. The review indicates that the H. pylori eradication rate of the dual therapy is overall comparable to or better than that of bismuth-containing quadruple therapy or standard triple therapy. It is more effective to administer both amoxicillin and PPI 3-4 times daily for 14 days in the high-dose amoxicillin-PPI dual therapy, and esomeprazole seems to be superior to other PPIs. EXPERT OPINION: The high-dose amoxicillin-PPI dual therapy is currently a promising H. pylori eradication regimen in clinical practice, deserving further verification and discussion. Much more attention should be paid to the influence of CYP2C19 polymorphisms and virulence genotyping on H. pylori eradication, and the homogeneity and objectivity of the comparison among different studies.