Review article: the global emergence of Helicobacter pylori antibiotic resistance

Seven Days of Bismuth-Based Quadruple Therapy Is as Effective for the First-Line Treatment of Clarithromycin-Resistant Confirmed Helicobacter pylori Infection as 14 Days of Bismuth-Based Quadruple Therapy

Background/Aims: Point mutations in the 23S ribosomal RNA gene have been associated with Helicobacter pylori (H. pylori) clarithromycin resistance and bismuth-based quadruple therapy (BQT) is one of the options for the treatment of clarithromycin-resistant H. pylori. Current H. pylori treatment guidelines recommend BQT for 10–14 days. This study aims to compare the eradication extents according to 7-day and 14-day BQT treatment for treatment-naïve clarithromycin-resistant confirmed H. pylori infection. Methods: We retrospectively investigated treatment-naïve H. pylori infection cases from March 2019 to December 2020, where patients were treated with BQT. Clarithromycin resistance was identified with a dual-priming oligonucleotide-based multiplex polymerase chain reaction method. We reviewed a total of 126 cases. Fifty-three subjects were treated with a 7-day BQT regimen (7-day group), and 73 subjects were treated with a 14-day BQT regimen (14-day group). We evaluated the total eradication extent of the BQT and compared the eradication extents of the two study groups. Results: Total eradication extent of H. pylori was 83.3% (105/126). The eradication extents of the two groups were as follows: 7-day group (81.1% (43/53)), 14-day group (84.9% (62/73), p = 0.572) by intention-to-treat analysis; 7-day group (95.6% (43/45)), 14-day group (92.5% (62/67), p = 0.518) by per-protocol analysis. The moderate or severe adverse event extents during the eradication were 30.2% (16/53) in the 7-day group and 19.2% (14/73) in the 14-day group (p = 0.152). Conclusions: The 7-day BQT regimen was as effective as the 14-day BQT regimen in the eradication of treatment-naïve clarithromycin-resistant H. pylori infection.

Efficacy and safety of high-dose esomeprazole-amoxicillin dual therapy for Helicobacter pylori rescue treatment: a multicenter, prospective, randomized, controlled trial

BACKGROUND

High-dose dual therapy (HDDT) with proton pump inhibitors (PPIs) and amoxicillin has attracted widespread attention due to its favorable efficacy in eradicating Helicobacter pylori (H. pylori). This study aimed to compare the efficacy and safety of high-dose PPI-amoxicillin dual therapy and bismuth-containing quadruple therapy for H. pylori rescue treatment.

METHODS

This was a prospective, randomized, multicenter, non-inferiority trial. Patients recruited from eight centers who had failed previous treatment were randomly (1:1) allocated to two eradication groups: HDDT (esomeprazole 40 mg and amoxicillin 1000 mg three times daily; the HDDT group) and bismuth-containing quadruple therapy (esomeprazole 40 mg, bismuth potassium citrate 220 mg, and furazolidone 100 mg twice daily, combined with tetracycline 500 mg three times daily; the tetracycline, furazolidone, esomeprazole, and bismuth [TFEB] group) for 14 days. The primary endpoint was the H. pylori eradication rate. The secondary endpoints were adverse effects, symptom improvement rates, and patient compliance.

RESULTS

A total of 658 patients who met the criteria were enrolled in this study. The HDDT group achieved eradication rates of 75.4% (248/329), 81.0% (248/306), and 81.3% (248/305) asdetermined by the intention-to-treat (ITT), modified intention-to-treat (MITT), and per-protocol (PP) analyses, respectively. The eradication rates were similar to those in the TFEB group: 78.1% (257/329), 84.2% (257/305), and 85.1% (257/302). The lower 95% confidence interval boundary (-9.19% in the ITT analysis, - 9.21% in the MITT analysis, and -9.73% in the PP analysis) was greater than the predefined non-inferiority margin of -10%, establishing a non-inferiority of the HDDT group vs. the TFEB group. The incidence of adverse events in the HDDT group was significantly lower than that in the TFEB group (11.1% vs. 26.8%, P  < 0.001). Symptom improvement rates and patients' compliance were similar between the two groups.

CONCLUSIONS

Fourteen-day HDDT is non-inferior to bismuth-containing quadruple therapy, with fewer adverse effects and good treatment compliance, suggesting HDDT as an alternative for H. pylori rescue treatment in the local region.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04678492.

Saccharomyces boulardii Allows Partial Patients to Avoid Reusing Bismuth Quadruple for Helicobacter pylori Rescue Therapy: A Single-Center Randomized Controlled Study

Background

The increasing rate of drug resistance often leads to Helicobacter pylori (H. pylori) eradication failure and needs the rescue therapy. Thus, the exploration of new rescue therapeutic regimens is important. The present study was designed to test the beneficial effects of Saccharomyces boulardii (S.boulardii) prior to H. pylori rescue therapy basing on bismuth quadruple.

Methods

One hundred H. pylori-infected patients were randomly divided into two groups: study group and control group. Patients in the study group (n=50) underwent two-stages therapy: patients started with S.boulardii monotherapy for 2 weeks, and then tested for H. pylori infection after resting for 4 weeks without any therapy, patients who were still positive for H. pylori continued with bismuth quadruple eradication therapy. For the control group (n=50), all patients were observed and were not treated with any gastric drugs or antibiotics for 6 weeks, then those who were still positive for H. pylori received the same eradication therapy as the study group. Eradication rate, adverse events and the cost-effectiveness of two regimens were analyzed in this study.

Results

The H.pylori eradication rate of ITT (intent-to-treat) analysis and PP (per-protocol) analysis in the first phase of treatment were significantly higher in the study group than the control groups respectively (28.0% vs 2.0%, p<0.001 and 30.4% vs 2.1% p<0.001). For the total treatment effect, there were no significant differences in the eradication rate of ITT analysis (78.0% vs 80.0%) or PP analysis (90.7% vs 88.9%) between the study group and the control group. The cost‐effectiveness ratio of the study group was slightly higher than that of the control group (8.95 vs 8.55). There were two patients in the study group and four patients in the control group with the adverse events, respectively. There was no significant difference on the incidence of adverse events between the two groups (p=0.68).

Conclusion

S.boulardii may serve as a beneficial treatment option before H. pylori rescue therapy since it callowed partial patients to avoid reusing bismuth quadruple.

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.

Empiric treatment vs susceptibility-guided treatment for eradicating H. pylori: Is it possible to change that paradigm using modern molecular methods?

Helicobacter pylori (H. pylori) infection is the most widespread infectious-contagious disease worldwide, reaching a prevalence of 50-80% in developing countries. Chronic infection is considered the main cause of chronic gastritis and has been related to other diseases, such as peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. The most common treatment is with eradication regimens that utilize three or four drugs, including a proton pump inhibitor (PPI) and the antibiotics, clarithromycin and amoxycillin or metronidazole. Empiric antibiotic use for eradicating the bacterium has led to a growing resistance to those drugs, reducing regimen efficacy and increasing costs for both the patient and the healthcare sector. In such a context, the development of noninvasive next-generation molecular methods holds the promise of revolutionizing the treatment of H. pylori. The genotypic and phenotypic detection of the resistance of the bacterium to antibiotics enables personalized treatment regimens to be provided, reducing costs and implementing an antibiotic stewardship program. The aims of the present narrative review were to analyze and compare the traditional and next-generation methods for diagnosing H. pylori, explain the different factors associated with eradication failure, and emphasize the impact of the increasing antibiotic resistance on the reversal and prevention of H. pylori-associated diseases.

Clinical practice of Helicobacter pylori infection management by gastroenterologists in secondary and tertiary hospitals: A stratified sampling cross-sectional survey

OBJECTIVE

To investigate the management of Helicobacter pylori (H. pylori) infection by gastroenterologists from secondary and tertiary hospitals in Shandong Province, China, where there is a high prevalence of H. pylori infection.

METHODS

A questionnaire-based, stratified sampling survey was conducted from June 1 to August 30, 2021. The ratio of secondary to tertiary hospitals was set at 2:1. An electronic questionnaire was sent to the gastroenterologists via the WeChat platform.

RESULTS

A total of 89.09% (1053/1182) gastroenterologists were included. Overall, 34.19% and 60.59% of gastroenterologists recommended screening for and treating H. pylori infection in patients without any competing factors. The most preferred testing method in secondary and tertiary hospitals was the ¹³ C-urea breath test (53.92% and 80.48%), but the reexamination rate of results close to the cut-off value was low (55.10% and 59.48%). Gastroenterologists preferred bismuth-containing quadruple therapy (secondary and tertiary hospitals: 96.67% and 98.53%), but the antibiotic combination prescribed for patients with penicillin allergy was suboptimal in secondary hospitals. The overall post-treatment follow-up rate was 64.58%, and gastroenterologists in secondary hospitals were more proactive than those in tertiary hospitals (69.41% vs 60.04%, P = 0.001). Less than 80% of gastroenterologists emphasized the importance of post-treatment reexamination to their patients. Only a minority of gastroenterologists in secondary and tertiary hospitals (30.79% and 34.36%) achieved acceptable eradication rates (exceeding 80%).

CONCLUSIONS

Deficiencies exist in gastroenterologists from secondary and tertiary hospitals, and the H. pylori eradication rate is relatively low. Training programs for gastroenterologists are warranted to strengthen their comprehension of guidelines.

In Vitro Activity of the Arylaminoartemisinin GC012 against Helicobacter pylori and Its Effects on Biofilm

This study evaluated the in vitro activity of the arylaminoartemisinin GC012, readily obtained from dihydroartemisinin (DHA), against clinical strains of Helicobacter pylori (H. pylori) with different antibiotic susceptibilities in the planktonic and sessile state. The activity was assessed in terms of bacteriostatic and bactericidal potential. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the broth microdilution method. After treatment with GC012, all bacterial strains showed significantly lower MIC and MBC values compared to those of DHA. The effect of combination of GC012 with antibiotics was examined using the checkerboard method. GC012 displayed synergistic interactions with metronidazole, clarithromycin, and amoxicillin in all the strains. The antibiofilm activity was evaluated via crystal violet staining, AlamarBlue^® assay, colony-forming unit count, and fluorescence microscopy. At ½ MIC and ¼ MIC concentration, both GC012 and DHA inhibited biofilm formation, but only GC012 showed a minimal biofilm eradication concentration (MBEC) on mature biofilm. Furthermore, both compounds induced structural changes in the bacterial membrane, as observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is thereby demonstrated that GC012 has the potential to be efficacious against H. pylori infection.

The Potential Use of Antibiotics Against Helicobacter pylori Infection: Biopharmaceutical Implications

Helicobacter pylori (H. pylori) is a notorious, recalcitrant and silent germ, which can cause a variety of debilitating stomach diseases, including gastric and duodenal ulcers and gastric cancer. This microbe predominantly colonizes the mucosal layer of the human stomach and survives in the inhospitable gastric microenvironment, by adapting to this hostile milieu. In this review, we first discuss H. pylori colonization and invasion. Thereafter, we provide a survey of current curative options based on polypharmacy, looking at pharmacokinetics, pharmacodynamics and pharmaceutical microbiology concepts, in the battle against H. pylori infection.

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.

Comparative Effectiveness of Various Eradication Regimens for Helicobacter Pylori Infection in the Northeastern Region of Poland

Purpose: Due to the lack of systematic data on antibiotic sensitivity, the treatment of the highly prevalent and pathogenic Helicobacter pylori (H. pylori) infection still poses a significant problem. Therefore, the aim of our study was to compare the efficacy of the three most commonly used anti-H. pylori therapies in northeastern Poland. Patients and Methods: This was a retrospective, single-center study performed on 289 outpatients with an H. pylori infection. Patients received one of the following three treatment regimens: (1) bismuth quadruple therapy (BQT) for 10 days, (2) metronidazole-based triple therapy (M-TT) for 10 or 14 days, and (3) levofloxacin-based triple therapy (L-TT) for 10 or 14 days. Results: BQT, M-TT, and L-TT accounted for 93.2% of prescribed anti-H. pylori therapies. The overall success rate for all treatment regimens was 84.1% (243/289). The effectiveness of first- and second-line therapy was similar and reached 83.8% and 86.2%, respectively. The efficacy of the individual treatment regimens was as follows: (1) BQT—89.4% (84/94), (2) M-TT—80.6% (112/139) and 78.8% (26/33) for 10 and 14 days, respectively, and (3) L-TT—84.6% (11/13) and 100% (10/10) for 10 and 14 days, respectively. The overall duration of treatment and type and dose of proton pump inhibitor (PPI) had no effect on the treatment efficacy. Conclusions: In the northeastern part of Poland, 10-day BQT and 10- or 14-day L-TT are effective treatment regimens for H. pylori eradication and have appear to be superior to M-TT. Practitioners in our clinic followed mostly local anti-H. pylori therapy guidelines.

A Survey of Helicobacter pylori Antibiotic-Resistant Genotypes and Strain Lineages by Whole-Genome Sequencing in China

Antibiotic resistance is the most important factor leading to failed Helicobacter pylori eradication therapy, and personalized treatment based on antibiotic susceptibility is becoming increasingly important. To strengthen the understanding of antibiotic genotypic resistance of H. pylori and identify new antibiotic resistance loci, in this study, we identified phenotypic resistance information for 60 clinical isolates and compared the concordance of phenotypic and genotypic resistance using whole-genome sequencing (WGS). Clarithromycin and levofloxacin genotypic resistance was in almost perfect concordance with phenotypic resistance, with kappa coefficients of 0.867 and 0.833, respectively. All strains with the R16H/C mutation and truncation in rdxA were metronidazole resistant, with 100% specificity. For other genes of concern, at least one phenotypically sensitive strain had a previous mutation related to antibiotic resistance. Moreover, we found that the A1378G mutation of HP0399 and the A149G mutation of FabH might contribute to tetracycline resistance and multidrug resistance, respectively. Overall, the inference of resistance to clarithromycin and levofloxacin from genotypic resistance is reliable, and WGS has been very helpful in discovering novel H. pylori resistance loci. In addition, WGS has also enhanced our study of strain lineages, providing new ways to understand resistance information and mechanisms.

[Sensitivity Comparison Experiment of Four Testing Methods for Helicobacter pylori]

Objective

To measure with standard microbiology methods the sensitivity of 4 commonly used testing methods for Helicobacter pylori (Hp) and to conduct a comparative study of the correlations and differences across the 4 methods.

Methods

With the Hp standard strain (SS1) as the reference, colony forming units (CFU) as the units of quantitative analysis for detection performance, and gradient dilution of SS1 suspension as the simulation sample, we measured the sensitivity of 4 Hp testing methods, including bacterial culture, rapid urease test, antigen test, and quantitative fluorescent PCR. CFU values at different concentrations corresponding to the 4 commonly used Hp testing methods were documented and the correlations and differences were analyzed accordingly.

Results

The sensitivity of Hp bacterial culture, rapid urease test, antigen test and quantitative fluorescent PCR was 2.0×10 CFU/mL, 2.0×10 5 CFU/mL, 2.0×10 5 CFU/mL, and 2.0×10 2 CFU/mL, respectively.

Conclusion

The testing turnover time and sensitivity of different laboratory methods for Hp testing varied significantly. The quantitative fluorescent PCR and bacterial culture both showed relatively high sensitivity, but bacterial culture has complicated operation procedures and is too time-consuming. The rapid urease test and antigen test both were simple and quick to perform, but showed low sensitivity. For clinical and laboratory testing of Hp, appropriate testing method that can identify the corresponding changes of Hp should be selected according to the actual testing purpose.

Delivering macrolide antibiotics to heal a broken heart - And other inflammatory conditions

Drug carriers to deliver macrolide antibiotics, such as azithromycin, show promise as antibacterial agents. Macrolide drug carriers have largely focused on improving the drug stability and pharmacokinetics, while reducing adverse reactions and improving antibacterial activity. Recently, macrolides have shown promise in treating inflammatory conditions by promoting a reparative effect and limiting detrimental pro-inflammatory responses, which shifts the immunologic setpoint from suppression to balance. While macrolide drug carriers have only recently been investigated for their ability to modulate immune responses, the previous strategies that deliver macrolides for antibacterial therapy provide a roadmap for repurposing the macrolide drug carriers for therapeutic interventions targeting inflammatory conditions. This review describes the antibacterial and immunomodulatory activity of macrolides, while assessing the past in vivo evaluation of drug carriers used to deliver macrolides with the intention of presenting a case for increased effort to translate macrolide drug carriers into the clinic.

Changing profile of Helicobacter pylori primary antibiotic resistance in Singapore over two decades

OBJECTIVES

Antibiotic resistance is a key reason for Helicobacter pylori (H. pylori) treatment failure and updated local data are important to guide the choice of empiric first-line therapy. Clarithromycin-based triple therapy (TT) is currently the first-line treatment in Singapore. Our primary aim was to determine the change in pattern of primary antibiotic resistance of H. pylori in Singapore as well as TT success rate.

METHODS

A registry of H. pylori isolates was tested for primary antibiotic resistance and were analyzed from year 2001 to 2020. Treatment outcome data based on 13C-urea breath test (13C-UBT) results of empiric first-line 2-week TT from 2019 to 2020 were also analyzed retrospectively.

RESULTS

A total of 387 H. pylori isolates were included. Rates of resistance to clarithromycin as well as tetracycline showed a downtrend in the last 5 years (clarithromycin: 2001-2002: 8.57%; 2007-2008: 14.14%; 2013-2014: 18.09%; 2019-2020: 13.71%; tetracycline: 2001-2002: 5.71%; 2007-2008: 7.07%; 2013-2014: 7.45%; 2019-2020: 0%). The resistance rate for amoxicillin remained low (2001-2002: 2.86%; 2007-2008: 5.05%; 2013-2014: 4.26%; 2019-2020: 7.26%). There was a steady increase in the rate of levofloxacin resistance (2001-2002: 5.71%; 2007-2008: 11.11%; 2013-2014: 15.96%; 2019-2020: 16.94%). From 2019 to 2020, the rate of successful TT was 91.67% (891/972).

CONCLUSION

The latest rate of clarithromycin resistance in 2019 to 2020 remained below the threshold of 15% and eradication rates remain high; thus, TT remains appropriate as an empiric first-line treatment in Singapore.

Experimental design and optimization of a novel dual-release drug delivery system with therapeutic potential against infection with Helicobacter pylori

The objective of this study was to develop clarithromycin-loaded lipid nanocarriers and incorporate them into microcapsules for pH-specific localized release of clarithromycin in the Helicobacter pylori microenvironment in order to obtain a gastro-retentive and pH-sensitive formulation. A Plackett-Burman design was applied to identify the effect of 5 factors on 3 responses. Then, a central composite design was applied to estimate the most important factors leading to the best compromise between lower particle size, polydispersity index and particle size changes. The optimized clarithromycin-loaded nanocapsules were employed to generate microcapsules by different methodologies. Nanocarriers and microcapsules were characterized in vitro. Experimental design and conditions were optimized to obtain nanocapsules of around 100 nm by a modified phase inversion-based process. High particle size homogeneity and high stability were achieved. At 4 °C both optimized lipid nanocapsules were stable during at least 365 days, confirming stability under those conditions. Clarithromycin incorporation in the nanocarrier was effective. Both types of microcoating were evaluated regarding their pH sensitivity. Spray drying microcapsules exhibited similar and uncontrolled release profiles at pH 2 and 7.4. Alternatively, when microcoatings were generated using an Encapsulator, release was insignificant at pH 2, while at pH 7.4 release was triggered, and appeared more appropriate to formulate microcapsules that release nanocarriers under pH neutral Helicobacter pylori microenvironment conditions, thereby permitting effective drug delivery in infected locations. The release of clarithromycin from lipid nanocarrier loaded microcapsules was pH-sensitive suggesting that this could be an effective strategy for clarithromycin delivery to the Helicobacter pylori microenvironment. Clarithromycin nanocapsules with and without microcoating showed a high anti-Helicobacter pylori activity in vitro.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

Factors Affect the Eradication Rate of Helicobacter pylori by Modified Quadruple Therapy: A Prospective Cohort Study

Objective

This study aimed to investigate related factors affecting the eradication rate of Helicobacter pylori (Hp) by modified quadruple therapy.

Methods

Between September 2020 and March 2021, 341 patients who were diagnosed with Hp infection and whose infections were confirmed by gastroscopy, a histological examination, and a C13-UBT without culturing and antimicrobial susceptibility studies received a two-week anti-Hp treatment, a modified quadruple therapy, in our department. The result of C13-UBT was rechecked 4 weeks after the drug withdrawal, and the patients were divided into two groups-a success group and a failure group-according to the final breath result. The general clinical information and related laboratory indexes of each patient were collected, and the factors affecting the eradication rate were analyzed.

Results

The total clinical eradication rate was 80.06% (273/341), and the failure rate was 19.94% (68/341), correspondingly. Univariate analysis identified statistically significant differences between the two groups in serum 25-hydroxyvitamin D levels, presence of oral diseases, positive cytotoxin-associated gene A (CagA), and medical compliance (P < 0.05). Meanwhile, the use of a proton pump inhibitor (PPIs) and antibiotics was statistically different (P < 0.05). Logistic regression analysis revealed that vitamin D level (<20 ng/mL) [OR = 98.56, 95% CI (29.01-334.83), P < 0.001] and medical compliance [OR = 148.18, 95% CI (37.64-583.33), P < 0.001] were independent effecting factors for eradication rate.

Conclusion

Serum 25-hydroxyvitamin D level lower than 20 ng/mL may affect the success of eradication of Hp and is an independent risk factor for eradication failure.

In vitro anti-Helicobacter pylori activity of Syzygium aromaticum and the preliminary mechanism of action

ETHNOPHARMACOLOGICAL RELEVANCE

The dried flower bud of Syzygium aromaticum (L.) Merr. & L.M Perry (S. aromaticum) (Myrtaceae), also known as clove, was used in Traditional Chinese Medicine (TCM) to aid gastrointestinal function and treat stomach disorders including vomiting, flatulence and nausea. And it is a food homology medicine which is a promising candidate for H. pylori treatment. H. pylori is a Gram-negative bacterium that infects approximately 50% of the human population worldwide, which is closely related to multiple gastric diseases, including gastric cancer. However, there are still no sufficient studies on the anti-H. pylori activity of S. aromaticum, especially for the mechanism of action.

AIM OF STUDY

This study aimed to study the antibacterial activities of S. aromaticum extracts on both antibiotic-sensitive and -resistant H. pylori strains, and to explore the underlying mechanisms of action.

MATERIALS AND METHODS

The S. aromaticum extracts were obtained by heat reflux extraction and lyophilized to powder form. The phytochemical analyses were performed by High-performance liquid chromatography (HPLC) and UPLC-electrospray ionization mass spectrometry (ESI-MS). In vitro anti-H. pylori activity was evaluated by broth microdilution method. Mechanism of action studies included morphological observation using electron microscopy, determination of expression of virulence genes by reverse transcription quantitative polymerase chain reaction (RT-qPCR), genes expression profile identification by transcriptomic analysis, and exploration of anti-H. pylori infection mechanisms by network pharmacology analysis and western blotting validation.

RESULTS

The S. aromaticum extracts, aqueous extract (AE) and 75% hydroalcoholic extract (HE), exerted significant antibacterial activities against both antibiotic-sensitive and -resistant H. pylori strains with MICs of 160∼320 μg/ml, without developing drug resistance. Among them, AE was bactericide to all the tested strains with MBCs of less than 4MIC, while HE was merely bacteriostatic to most of the tested strains with MBCs of 2MIC∼16MIC. Besides, they showed no antagonistic effects in combination with clarithromycin, metronidazole, levofloxacin, and amoxicillin. Additionally, these extracts altered the morphology and ultrastructure and down-regulated the virulence genes expression of H. pylori. And transcriptomic analysis showed that they regulated genes expression of multiple H. pylori biological processes, including tricarboxylic acid cycle (TAC) and pyruvate metabolic pathways. Furthermore, these extracts combated the abnormal activation of PI3K-Akt and MAPK signaling pathways caused by H. pylori infection.

CONCLUSIONS

Overall, the present study firstly analyzed the chemical compositions of S. aromaticum extracts, and then confirmed their activities on both antibiotic-sensitive and -resistant H. pylori strains. In addition, the mechanisms of action of S. aromaticum extracts against H. pylori were found to be destroying the bacterial structure, down-regulating the expression of virulence genes, and interfering TAC and pyruvate metabolic pathways. Finally, S. aromaticum extracts were found to combated the abnormal activation of PI3K-Akt and MAPK signaling pathways to treat H. pylori infection. This study should accelerate further research and application of S. aromaticum against H. pylori infection.

Investigation of Plant Antimicrobial Peptides against Selected Pathogenic Bacterial Species Using a Peptide-Protein Docking Approach

Antimicrobial resistance is the key threat to global health due to high morbidity and mortality. The alteration of bacterial proteins, enzymatic degradation, and change of membrane permeability towards antimicrobial agents are the key mechanisms of antimicrobial resistance. Based on the current condition, there is an urgent clinical need to develop new drugs to treat these bacterial infections. In the current study, the binding patterns of selected antimicrobial peptides (AMPs) with different multidrug-resistant bacterial strains have been analyzed. Among ten selected AMPs in this study, napin and snakin-1 exhibited the best scores and binding patterns. Napin exhibited strong interactions with penicillin-binding protein 1a of Acinetobacter baumannii (with a binding score of -158.7 kcal/mol and ten hydrogen bonds), with glucose-1-phosphate thymidylyltransferase of Mycobacterium tuberculosis H37Rv (with a binding score of -107.8 kcal/mol and twelve hydrogen bonds), and with streptomycin 3^″-adenylyltransferase protein of Salmonella enterica (with a binding score of -84.2 kcal/mol and four hydrogen bonds). Similarly, snakin-1 showed strong interactions with oxygen-insensitive NADPH nitroreductase of Helicobacter pylori (with a binding score of -105.0 kcal/mol and thirteen hydrogen bonds) and with penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus (with a binding score of -103.8 kcal/mol and twenty-three hydrogen bonds). The docking results were further validated by molecular dynamics simulations. The results of this computational approach support the evidence of efficiency of these AMPs as potent inhibitors of these specific proteins of bacterial strains. However, further validations are required to fully evaluate the potential of selected AMPs as drug candidates against these resistant bacterial strains.

Interplay between Amoxicillin Resistance and Osmotic Stress in Helicobacter pylori

Rising antibiotic resistance rates are a growing concern for all pathogens, including Helicobacter pylori. We previously examined the association of specific mutations in PBP1 with amoxicillin resistance and fitness in H. pylori and found that V374L and N562Y mutations were associated with resistance, but also resulted in fitness defects. Furthermore, we found that hyperosmotic stress differentially altered the fitness of strains bearing these mutations; survival of the V374L strain was decreased by hyperosmotic stress, but the N562Y strain showed increased cell survival relative to that of wild-type G27. The finding that amoxicillin-resistant strains show environmentally dictated changes in fitness suggests a previously unexplored interaction between amoxicillin resistance and osmotic stress in H. pylori. Here, we further characterized the interaction between osmotic stress and amoxicillin resistance. Wild-type and isogenic PBP1 mutant strains were exposed to amoxicillin, various osmotic stressors, or combined antibiotic and osmotic stress, and viability was monitored. While subinhibitory concentrations of NaCl did not affect H. pylori viability, the combination of NaCl and amoxicillin resulted in synergistic killing; this was true even for the antibiotic-resistant strains. Moreover, similar synergy was found with other beta-lactams, but not with antibiotics that did not target the cell wall. Similar synergistic killing was also demonstrated when KCl was utilized as the osmotic stressor. Conversely, osmolar equivalent concentrations of sucrose antagonized amoxicillin-mediated killing. Taken together, our results support a previously unrecognized interaction between amoxicillin resistance and osmotic stress in H. pylori. These findings have interesting implications for the effectiveness of antibiotic therapy for this pathogen. IMPORTANCE Rising antibiotic resistance rates in H. pylori are associated with increased rates of treatment failure. Understanding how stressors impact antibiotic resistance may shed light on the development of future treatment strategies. Previous studies found that mutations in PBP1 that conferred resistance to amoxicillin were also associated with a decrease in bacterial fitness. The current study demonstrated that osmotic stress can enhance beta lactam-mediated killing of H. pylori. The source of osmotic stress was found to be important for these interactions. Given that relatively little is known about how H. pylori responds to osmotic stress, these findings fill important knowledge gaps on this topic and provide interesting implications for the effectiveness of antibiotic therapy for this pathogen.

Effects of enhanced education for patients with the Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infections are of serious concern due to the associated risk of gastric cancer. However, many patients have poor medication and therapy compliance, which makes it difficult to eradicate their infections. This points to the need for stronger educational interventions aimed at enhancing compliance, thus increasing the potential for treatment success. As such, this study conducted a meta-analysis to clarify the effects of enhanced patient education (EPE) programs for H. pylori.

MATERIALS AND METHODS

We searched electronic databases (PubMed, EMBASE, Web of Science, and Cochrane Library) for randomized controlled trials (RCTs) on health education for patients infected with H. pylori from inception to June 2021. The primary outcome was the eradication rate of H. pylori, while the secondary outcomes included the incidence of individual adverse symptoms, treatment compliance, clinical symptom remission after treatment, and patient satisfaction. We used the fixed or random-effects model to pool the risk ratio (RR), with 95% confidence interval. We also conducted sensitivity and subgroup analyses.

RESULTS

Our search returned seven relevant studies across a total of 1,433 patients. Compared with controls, EPE was significantly associated with improved H. pylori eradication rates (RR = 1.16, 95%CI: 1.04-1.29, p = 0.006) and patient compliance (RR = 1.48, 95%CI: 1.14-1.93, p = 0.003). A subgroup analysis also showed that EPE benefits were consistent across patients with different eradication programs, WeChat intervention plans, and intervention frequencies (p < 0.05). However, there were no significant differences in the total adverse effects, common side effects (diarrhea, nausea, abdominal pain, taste disorder, and skin rash), or discontinuation rate (p > 0.05).

CONCLUSIONS

Patient education is inexpensive, safe, and convenient. In this context, our findings suggest that enhanced educational interventions have positive effects on both the H. pylori eradication rate and adherence among infected patients, and thus constitute promising complements to clinical treatment regimens.

Exploration of the molecular mechanisms underlying the antibiotic resistance of Helicobacter pylori: A whole-genome sequencing-based study in Southern China

BACKGROUND

Although antimicrobial resistance (AMR) in Helicobacter pylori is a global threat to human health and the underlying molecular mechanisms have been explored previously, only a few of them are fully elucidated.

MATERIALS AND METHODS

In the present study, we isolated 54 Helicobacter pylori strains from Southern China and assessed their susceptibility to five antibiotics using the agar dilution assay. Whole-genome sequencing was performed to screen the AMR genotypes of the Helicobacter pylori isolates.

RESULTS

Our study revealed a high prevalence of resistance to clarithromycin (CLR), levofloxacin (LVX), and metronidazole (MTZ) in the Chinese isolates, 55.56% of which showed multidrug-resistant phenotypes. We screened for the 94 types of previously reported AMR mutations in 12 genes, but only a few of them were related to the AMR phenotype. Furthermore, we discovered four new mutations in the 23S rRNA gene and one mutation in infB related to CLR resistance. Another three mutations in gyrA and one in gyrB were closely correlated with the AMR pattern against LVX. We also demonstrated that the mutations R16C/H in rdxA, V56I in rpsU, and D54A in sodB might contribute to resistance to MTZ, which were previously reported in laboratory experiments but not found in clinical strains. We examined the concordance between the genotype and phenotype of AMR and identified several potential molecular biomarkers for predicting CLR and LVX resistance.

CONCLUSIONS

Our study explored the molecular mechanisms underlying the antibiotic resistance of Helicobacter pylori isolates from Southern China. We propose further epidemiologic investigations in China.

Correlation Analysis Among Genotype Resistance, Phenotype Resistance, and Eradication Effect After Resistance-Guided Quadruple Therapies in Refractory Helicobacter pylori Infections

Objectives

The antimicrobial resistance of Helicobacter pylori (H. pylori) in most countries and regions has increased significantly. It has not been fully confirmed whether the detection of H. pylori resistance gene mutation can replace antibiotic drug sensitivity test to guide the clinical personalized treatment. The objective of this study was to assess and compare the efficacy of different antimicrobial resistance-guided quadruple therapies in refractory H. pylori-infected individuals who had undergone unsuccessful prior eradication treatments.

Methods

From January 2019 to February 2020, genotypic and phenotypic resistances were determined by polymerase chain reaction (PCR), whole genome sequencing (WGS) and broth microdilution test, respectively, in 39 H. pylori-infected patients who have failed eradication for at least twice. The patients were retreated with bismuth quadruple therapy for 14 days according to individual antibiotic resistance results. Eradication status was determined by the ¹³C-urea breath test.

Results

The overall eradication rate was 79.5% (31/39, 95% CI 64.2–89.5%) in the intention-to-treat (ITT) analysis and 88.6% (31/35, 95% CI 73.5–96.1%) in the per- protocol analysis (PP) analysis. The presence of amoxicillin resistance (OR, 15.60; 95% CI, 1.34–182.09; p = 0.028), female sex (OR, 12.50; 95% CI, 1.10–142.31; p = 0.042) and no less than 3 prior eradication treatments (OR, 20.25; 95% CI, 1.67–245.44; p = 0.018), but not the methods for guiding therapy (p > 0.05) were associated with treatment failure. Resistance-guided therapy achieved eradication rates of more than 80% in these patients. The eradication rate of H. pylori in the phenotypic resistance-guided group was correlated well with genotype resistance-guided groups, including PCR and WGS.

Conclusion

Culture or molecular method guiding therapy can enable personalized, promise salvage treatments, and achieve comparably high eradication rates in patients with refractory H. pylori infection. The detection of H. pylori resistance mutations has a good clinical application prospect.

Protocol Study Register

[clinicaltrials.gov], identifier [ChiCTR1800020009].

Second line therapy for Helicobacter pylori eradication: state of art

Helicobacter pylori (H. pylori) is a Gram negative spiraliform bacterium who colonizes the human stomach. It is the most common cause of chronic gastritis, peptic ulcer, and gastric carcinoma. The eradication therapy is based on the combination of a proton pump inhibitor and several antibiotics such as amoxicillin, metronidazole, clarithromycin, levofloxacin or tetracycline. The most commonly used regimens for eradication in the first line are triple, sequential and concomitant therapy, despite the last European Guidelines suggesting a quadruple therapy already at the first attempt in areas with high resistance rates. However, the rise in antibiotic resistance is the main reason for a marked increase in first-line therapy failure. Clarithromycin resistancea , is especially acknowledged as the most important event resulting in failure. Up to 20% of patients are intended not to eradicate, therefore they will need a second line therapy. Currently, the most used rescue regimens are levofloxacin-based triple therapy and bismuth-containing quadruple therapy, despite guidelines suggesting to use a combination of antibiotics that have not been included in previous treatments. Nitazoxanide is a novel antibiotic with promising results. Additionally, an interesting field worth of investigation is the antibiotic susceptibility based approach, which could help to choose antibiotics with confirmed effectiveness in vitro. Analysis of antibiotic resistance may be performed by both bacterial culture and molecular biology techniques, able to detect point mutations conferring resistance. This is a particularly interesting approach, since it may personalize the therapy, thus optimizing the regimen and maximizing the probability of success.

Investigating the effect of quadruple therapy with Saccharomyces boulardii or Lactobacillus reuteri strain (DSMZ 17648) supplements on eradication of Helicobacter pylori and treatments adverse effects: a double-blind placebo-controlled randomized clinical trial

Background

The goal of this study was to investigate the effects of treatment with Saccharomyces boulardii and Lactobacillus reuteri on the eradication of Helicobacter pylori and Adverse effects (AEs) of the treatment.

Results

This study was a double-blind, randomized, placebo-controlled trial. And, eradication of H. pylori was reported comparing quadruple therapy include of PPI (proton pomp inhibitor), bismuth subcitrate, clarithromycin, and amoxicillin versus quadruple therapy supplemented with S. boulardii and L. reuteri DSMZ 17648. For this aim, a total of 156 patients were included in the current study; and patients positive for H. pylori infection (n = 156) were randomly assigned to 3 groups: 52 patients (Group P) received conventional quadruple therapy plus L. reuteri, 52 patients (Group S) received conventional quadruple therapy plus S. boulardii daily, for 2 weeks, and 52 patients were in the control group (Group C). At the end of the treatment period, all the subjects continued to take proton pump inhibitor (PPI) alone for 14 days, and then, no medication was given for 2 weeks again. During follow-up, gastrointestinal symptoms were assessed using an evaluation scale (Glasgow dyspepsia questionnaire [GDQ]), and AEs were assessed at 7, 14, 21, and 28 days. As a result, all patients completed the treatment protocol in all groups by the end of the study. Additionally, eradication therapy was effective for 94.2% of subjects in Group S, 92.3% of subjects in Group P, and 86.5% of subjects in the control group, with no differences between treatment arms. In Group S, the chance of developing symptoms of nausea (OR = 2.74), diarrhea (OR = 3.01), headache (OR = 10.51), abdominal pain (OR = 3.21), and anxiety (OR = 3.58) was significantly lower than in the control group (p < 0.05).

Conclusion

S. boulardii could significantly reduce some AEs of H. pylori eradication therapy, but effectiveness of Lactobacillus reuteri on these cases was not significant. It is recommended to conduct the future research with larger sample size in order to investigate the effect.

Trial registration: IRCT20200106046021N1, this trial was registered on Jan 14, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02187-z.

Nuclease activity: an exploitable biomarker in bacterial infections

INTRODUCTION

In the increasingly challenging field of clinical microbiology, diagnosis is a cornerstone whose accuracy and timing are crucial for the successful management, therapy, and outcome of infectious diseases. Currently employed biomarkers of infectious diseases define the scope and limitations of diagnostic techniques. As such, expanding the biomarker catalog is crucial to address unmet needs and bring about novel diagnostic functionalities and applications.

AREAS COVERED

This review describes the extracellular nucleases of 15 relevant bacterial pathogens and discusses the potential use of nuclease activity as a diagnostic biomarker. Articles were searched for in PubMed using terms: "nuclease", "bacteria", "nuclease activity" or "biomarker". For overview sections, original and review articles between 2000 and 2019 were searched for using terms: "infections", "diagnosis", "bacterial", "burden", "challenges". Informative articles were selected.

EXPERT OPINION

Using the catalytic activity of nucleases offers new possibilities compared to established biomarkers. Nucleic acid activatable reporters in combination with different transduction platforms and delivery methods can be used to detect disease-associated nuclease activity patterns in vitro and in vivo for prognostic and diagnostic applications. Even when these patterns are not obvious or of unknown etiology, screening platforms could be used to identify new disease reporters.

In vitro antibacterial activity of nimbolide against Helicobacter pylori

ETHNOPHARMACOLOGICAL RELEVANCE

Nimbolide is one of hundreds of phytochemicals that have been identified within the neem tree (Azadirachta indica A. Juss). As an evergreen tree native to the Indian subcontinent, components of the neem tree have been used for millennia in traditional medicine to treat dental, gastrointestinal, urinary tract, and blood-related ailments, ulcers, headaches, heartburn, and diabetes. In modern times, natural oils and extracts from the neem tree have been found to have activities against a variety of microorganisms, including human pathogens.

AIM OF THE STUDY

Helicobacter pylori, a prevalent gastric pathogen, shows increasing levels of antibiotic resistance. Thus, there is an increasing demand for novel therapeutics to treat chronic infections. The in vitro activity of neem oil extract against H. pylori was previously characterized and found to be bactericidal. Given the numerous phytochemicals found in neem oil extract, the present study was designed to define and characterize specific compounds showing bactericidal activity against H. pylori.

MATERIALS AND METHODS

Azadirachtin, gedunin, and nimbolide, which are all common in neem extracts, were tested for antimicrobial activity; the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for nine strains of H. pylori. The specific properties of nimbolide were further characterized against H. pylori strain G27. Bactericidal kinetics, reversibility, effectiveness at low pH, and activity under bacteriostatic conditions were examined. The hemolytic activity of nimbolide was also measured. Finally, neem oil extract and nimbolide effectiveness against H. pylori biofilms were examined in comparison to common antibiotics used to treat H. pylori infection.

RESULTS

Nimbolide, but not azadirachtin or gedunin, was effective against H. pylori; MICs and MBCs against the nine tested strains ranged between 1.25-5 μg/mL and 2.5-10 μg/mL, respectively. Additionally, neem oil extract and nimbolide were both effective against H. pylori biofilms. Nimbolide exhibited no significant hemolytic activity at biologically relevant concentrations. The bactericidal activity of nimbolide was time- and dose-dependent, independent of active H. pylori growth, and synergistic with low pH. Furthermore, nimbolide-mediated H. pylori cell death was irreversible after exposure to high nimbolide concentrations (80 μg/mL, after 2 h of exposure time and 40 μg/mL after 8 h of exposure).

CONCLUSIONS

Nimbolide has significant bactericidal activity against H. pylori, killing both free living bacterial cells as well as cells within a biofilm. Furthermore, the lack of hemolytic activity, synergistic activity at low pH and bactericidal properties even against bacteria in a state of growth arrest are all ideal pharmacological and biologically relevant properties for a potential new agent. This study underscores the potential of neem oil extract or nimbolide to be used as a future treatment for H. pylori infection.

Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms

Helicobacter pylori is an organism associated with ulcer disease and gastric cancer. The latter is one of the most prevalent malignancies and currently the fourth major cause of cancer-related deaths globally. The pathogen infects about 50% of the world population, and currently, no treatment ensures its total elimination. There has been an increase in our understanding of the pathophysiology and pathogenesis mechanisms of H. pylori over the years. H. pylori can induce several genetic alterations, express numerous virulence factors, and trigger diverse adaptive mechanisms during its adherence and colonization. For successful colonization and infection establishment, several effector proteins/toxins are released by the organism. Evidence is also available reporting spiral to coccoid transition as a unique tactic H. pylori uses to survive in the host's gastrointestinal tract (GIT). Thus, the virulence and pathogenicity of H. pylori are under the control of complex interplay between the virulence factors, host, and environmental factors. Expounding the role of the various virulence factors in H. pylori pathogenesis and clinical outcomes is crucial for vaccine development and in providing and developing a more effective therapeutic intervention. Here we critically reflect on H. pylori infection and delineate what is currently known about the virulence and pathogenesis mechanisms of H. pylori.

Characterization of Metronidazole-Resistant Giardia intestinalis Lines by Comparative Transcriptomics and Proteomics

Metronidazole (MTZ) is a clinically important antimicrobial agent that is active against both bacterial and protozoan organisms. MTZ has been used extensively for more than 60 years and until now resistance has been rare. However, a recent and dramatic increase in the number of MTZ resistant bacteria and protozoa is of great concern since there are few alternative drugs with a similarly broad activity spectrum. To identify key factors and mechanisms underlying MTZ resistance, we utilized the protozoan parasite Giardia intestinalis, which is commonly treated with MTZ. We characterized two in vitro selected, metronidazole resistant parasite lines, as well as one revertant, by analyzing fitness aspects associated with increased drug resistance and transcriptomes and proteomes. We also conducted a meta-analysis using already existing data from additional resistant G. intestinalis isolates. The combined data suggest that in vitro generated MTZ resistance has a substantial fitness cost to the parasite, which may partly explain why resistance is not widespread despite decades of heavy use. Mechanistically, MTZ resistance in Giardia is multifactorial and associated with complex changes, yet a core set of pathways involving oxidoreductases, oxidative stress responses and DNA repair proteins, is central to MTZ resistance in both bacteria and protozoa.

Factors Affecting the Intraluminal Therapy for Helicobacter pylori Infection

Helicobacter pylori (H. pylori) can be eradicated immediately while conducting an endoscopic examination. The eradication rate of intraluminal therapy for H. pylori infection (ILTHPI) is 53.7% (51/95) via local application of single-dose medicament containing amoxicillin, metronidazole, and clarithromycin. We aimed to evaluate factors affecting ILTHPI and to assess the efficacy among single antibiotics, and compared our results with combined antibiotics. We enrolled H. pylori-infected treatment-naïve symptomatic patients; 95 completed triple-antibiotic ILTHPI were evaluated for risk factors, along with 60 completed mono-antibiotic ILTHPI containing amoxicillin, clarithromycin, or metronidazole in each of the 20 patients. Univariate analysis revealed the significant influence of BMI (OR: 1.15; 95% CI: 1.03–1.27, p = 0.011) and gastric juice pH (OR: 1.35; 95% CI: 1.16–1.58, p = 0.0001). Logistic regression analysis also showed significant influence of gastric juice pH (OR: 1.30; 95% CI: 1.10–1.54, p = 0.002). The eradication rate of mono-antibiotic ILTHPI is significantly lower than triple-antibiotic ILTHPI (11.7% vs. 53.7%; p < 0.0001; α = 0.05, power = 1.0). The efficacy was 20% (4/20) for metronidazole, 10% (2/20) for amoxicillin, and 5% (1/20) for clarithromycin. In conclusion, the level of gastric juice pH is a crucial factor affecting the ILTHPI. The detection of gastric juice pH and selection of optimal intraluminal medicaments are important. Further studies with combined antibiotics for ILTHPI, perhaps metronidazole-containing medicaments, are recommended.

Adherence to international guidelines for the management of Helicobacter pylori infection among gastroenterologists and gastroenterology fellows in Italy: A Survey of the Italian Federation of Digestive Diseases - FISMAD

BACKGROUND

Information on the management of Helicobacter (H.) pylori infection by gastroenterologists and gastroenterology fellows are scarce. We aimed to assess practice of gastroenterologists and gastroenterology fellows and their adherence to guidelines for diagnosis and treatment of H. pylori infection in Italy.

MATERIALS AND METHODS

All gastroenterologists and gastroenterology fellows attending the National Congress of Digestive Diseases - FISMAD were invited to fill-in an on-line questionnaire. The questionnaire included questions on the diagnosis and treatment of H. pylori infection.

RESULTS

A total of 279 gastroenterologists and 61 gastroenterology fellows participated to the study. The 13 C-urea breath test was the most preferred method among gastroenterologists and fellows for the diagnosis of H. pylori infection (40.4% and 57.6%, respectively) and the confirmation of eradication (61.3% and 70%, respectively). Sequential therapy was the most preferred first-line treatment of H. pylori for both gastroenterologists and gastroenterology fellows (31.8% and 44%, respectively), followed by bismuth quadruple therapy (31% and 27.6%, respectively) and clarithromycin triple therapy (26.8% and 22.4%, respectively). Only 30% of gastroenterologists and 38.5% of fellows used the clarithromycin triple therapy for the recommended duration of 14 days. Bismuth quadruple therapy was the most preferred second-line therapy for both gastroenterologists and fellows. The majority of gastroenterologists and fellows would prefer an empirical therapy at third line (72.6% and 62.5%, respectively) and a susceptibility-guided therapy at fourth line (46.7% and 71.4%, respectively).

CONCLUSIONS

Practices of gastroenterologists and gastroenterology fellows are in line with guidelines' recommendations, apart for the first-line treatment of H. pylori infection. Targeted educational interventions to improve adherence to guidelines are needed.

Worldwide and Regional Efficacy Estimates of First-line Helicobacter pylori Treatments: A Systematic Review and Network Meta-Analysis

BACKGROUND

Eradication of Helicobacter pylori infection is challenging. We aimed to determine the optimal first-line H. pylori treatments at global and regional levels.

METHODS

We searched Embase, PubMed, Cochrane CENTRAL, Web of Science, Scopus, WHO ICTRP, ClinicalTrials.gov, and ISRCTN registry, for randomized controlled trials published during 2011-2020. Utilizing a network meta-analysis in a Bayesian framework, success rates of 23 regimens were compared. The effect size was standardized risk ratio (RR) with 95% credible interval (CrI). Pooled eradication rate (ER) with 95% CrI was also reported for top combinations. The reference regimen was 7-day clarithromycin-based triple therapy.

RESULTS

This review identified 121 trials comprising 34,759 participants. Globally, 14-day levofloxacin-based sequential therapy was the most efficient (RR: 1.43; 95% CrI, 1.26-1.59) with low certainty of evidence, followed by modified bismuth-containing quadruple therapy (proton pump inhibitor+bismuth compounds+clarithromycin+amoxicillin) for 10 days (RR: 1.35; 95% CrI, 1.22-1.48) and 14 days (RR: 1.27; 95% CrI, 1.12-1.42), and 14-day hybrid therapy (RR: 1.27; 95% CrI, 1.19-1.36). The corresponding ERs were 98.7% (95% CrI, 86.9-100.0), 93.2% (95% CrI, 84.2-100.0), 87.6% (95% CrI, 82.1-93.8), and 87.6% (95% CrI, 77.3-98.0), respectively. Continentally, the most effective combinations were: 10-day clarithromycin-based sequential therapy [(RR: 1.21; 95% CrI, 1.02-1.42), (ER: 89.5%, 95% CrI, 75.5-100.0)] for Africa, 14-day levofloxacin-based sequential therapy [(RR: 1.41; 95%CrI, 1.27-1.58), (ER: 98.7%, 95% CrI, 88.9-100.0)] for Asia, and 14-day clarithromycin-based triple therapy [(RR: 1.58; 95% CrI, 1.25-2.04), (ER: 94.8%; 95% CrI, 75.0-100.0)] for Europe. For Northern America, no sufficient data were found for network meta-analysis. In South America, none of the combinations were superior to the reference regimen.

CONCLUSION

Although results of this network meta-analysis revealed optimal combinations for empiric therapy, the treatment preference would be based on the local pattern of antibacterial resistance, when the necessary information exists.

Improving Antibacterial Activity of a HtrA Protease Inhibitor JO146 against Helicobacter pylori: A Novel Approach Using Microfluidics-Engineered PLGA Nanoparticles

Nanoparticle drug delivery systems have emerged as a promising strategy for overcoming limitations of antimicrobial drugs such as stability, bioavailability, and insufficient exposure to the hard-to-reach bacterial drug targets. Although size is a vital colloidal feature of nanoparticles that governs biological interactions, the absence of well-defined size control technology has hampered the investigation of optimal nanoparticle size for targeting bacterial cells. Previously, we identified a lead antichlamydial compound JO146 against the high temperature requirement A (HtrA) protease, a promising antibacterial target involved in protein quality control and virulence. Here, we reveal that JO146 was active against Helicobacter pylori with a minimum bactericidal concentration of 18.8–75.2 µg/mL. Microfluidic technology using a design of experiments approach was utilized to formulate JO146-loaded poly(lactic-co-glycolic) acid nanoparticles and explore the effect of the nanoparticle size on drug delivery. JO146-loaded nanoparticles of three different sizes (90, 150, and 220 nm) were formulated with uniform particle size distribution and drug encapsulation efficiency of up to 25%. In in vitro microdilution inhibition assays, 90 nm nanoparticles improved the minimum bactericidal concentration of JO146 two-fold against H. pylori compared to the free drug alone, highlighting that controlled engineering of nanoparticle size is important in drug delivery optimization.

In silico design and in vitro assessment of anti-Helicobacter pylori compounds as potential small-molecule arginase inhibitors

Related to a variety of gastrointestinal disorders ranging from gastric ulcer to gastric adenocarcinoma, the infection caused by the gram-negative bacteria Helicobacter pylori (H. pylori) poses as a great threat to human health; hence, the search for new treatments is a global priority. The H. pylori arginase (HPA) protein has been widely studied as one of the main virulence factors of this bacterium, being involved in the prevention of nitric oxide-mediated bacterial cell death, which is a central component of innate immunity. Given the growing need for the development of new drugs capable of combating the infection by H. pylori, the present work describes the search for new HPA inhibitors, using virtual screening techniques based on molecular docking followed by the evaluation of the proposed modes of interaction at the HPA active site. In vitro studies of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), followed by cytotoxicity activity in gastric adenocarcinoma and non-cancer cells, were performed. The results highlighted compounds 6, 11, and 13 as potential inhibitors of HPA; within these compounds, the results indicated 13 presented an improved activity toward H. pylori killing, with MIC and MBC both at 64 µg/mL. Moreover, compound 13 also presented a selectivity index of 8.3, thus being more selective for gastric adenocarcinoma cells compared to the commercial drug cisplatin. Overall, the present work demonstrates the search strategy based on in silico and in vitro techniques is able to support the rational design of new anti-H. pylori drugs.

Efficacy of Twice a Day Bismuth Quadruple Therapy for Second-Line Treatment of Helicobacter pylori Infection

Bismuth quadruple therapy (BQT) is an effective treatment for Helicobacter pylori infection. However, frequent dosing schedules of BQT regimen often compromise drug adherence and may affect treatment outcomes. This retrospective study aimed to investigate the efficacy of twice-daily BQT compared to that of four times a day therapy. From August 2018 to November 2020, adult patients who failed first-line standard triple therapy and underwent BQT were eligible. Patients were categorized into two groups according to dosing schedule: (i) the BQT group (n = 213) who received standard BQT administered four times a day; and (ii) the BQTb group (n = 141) who received proton pump inhibitor, bismuth 600 mg, metronidazole 500 mg, and tetracycline 1 g twice a day. The eradication rate did not differ between the BQT (92.5%) and the BQTb groups (90.1%) (p = 0.441). Adherence and adverse event rate were similar between the two groups. Multivariate analysis showed that current smoking was associated with eradication failure; however, dosing frequency was not associated with the efficacy of eradication therapy. This study suggested that twice a day BQT is as effective as four times a day therapy for second-line treatment of H. pylori infection.

The impacts of probiotics in eradication therapy of Helicobacter pylori

Helicobacter pylori (H. pylori) is a well-known pathogen that infects approximately half of the world's population. It is a pathogenic agent with potential health hazards related to diverse diseases, especially digestive diseases, such as chronic gastritis, peptic ulcer, and gastric carcinoma. In clinical, antibiotics are commonly applied in eradication therapy of H. pylori. However, the increase in antibiotic resistance and side effects has induced the failure of eradication therapy. Recent studies have shown that probiotic supplementation has promising application prospects. It can restore the gastrointestinal microbiota balance and prevent dysbacteriosis caused by antibiotics. Furthermore, it has been reported to have direct or indirect inhibitory effects on H. pylori. Probiotics may have a beneficial effect on H. pylori eradication. However, the strain, dosages, duration times, and safety of probiotic supplementation need further study before clinical applications.

Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni²⁺ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

RP-HPLC-DAD Method Development and Validation for Simultaneous Determination of Lansoprazole, Tinidazole, Amoxicillin and Naproxen in Their Raw Materials and Combined Dosage Form: DOE Approach for Optimization of the Proposed Method

BACKGROUND

Helicobacter pylori infection is a common cause of peptic ulcer disease and dyspepsia. In addition, it may result in gastric cancer and gastric mucosa associated lymphoid tissue lymphoma. First-line therapy usually is consisted of triple therapy containing Clarithromycin or Amoxicillin, one of the proton pump inhibitors and Metronidazole or Tinidazole. In addition to the triple therapy, an analgesic is required to relieve the pain such as; Naproxen.

OBJECTIVE

A sensitive and selective method need to be developed and validated for simultaneous determination of four drugs (Amoxacillin, Tinidazole, Naproxen and Lansoprazole) used for treating Helicobacter pylori in their combined dosage forms.

METHODS

With the aid of experimental design, the cited drugs were separated and quantified. HPLC with diode array detector was used and metronidazole was the internal standard which is one of the drugs used for that case also. A thermo Scientific BDS Hypersil C18 column (5 µm, 250 mm x 4.6 mm) with mobile phase composed of acetonitrile: water (40:60, v/v), pH = 5 adjusted with phosphoric acid at 30° C was used for the separation of the cited drugs.

RESULTS

The method was linear over concentration ranges 10-500 µg/mL for Amoxacillin, 10-350 µg/mL for Tinidazole, 10-250 µg/mL for Naproxen and 2-20 μg/mL for Lansoprazole. The proposed method was fully validated according to ICH guidelines. Statistical analysis revealed no significant difference between the results obtained and the four reference methods for investigated drugs.

CONCLUSION

The method can be easily implemented in quality control studies of the cited drugs in their dosage forms.

HIGHLIGHTS

Experimental design was applied using Plackett-Burman design for preliminary screening of factors followed by Box-Behnken design for chromatographic method optimization.

Ninety-four thousand-case retrospective study on antibacterial drug resistance of Helicobacter pylori

BACKGROUND

The resistance rate to antibacterial drugs is the key inhibitor of Helicobacter pylori (H. pylori) eradication treatment.

AIM

To evaluate the prevalence and drug resistance of H. pylori based on big data.

METHODS

Gastric mucosal specimens were collected from naive patients undergoing upper gastrointestinal endoscopy for H. pylori culture and antimicrobial susceptibility testing (AST), including clarithromycin, levofloxacin, metronidazole and amoxicillin. Every 10 years of age was grouped as an age group. The H. pylori infection and resistance were explored based on the age group and gender.

RESULTS

The number of H. pylori-positive specimen was 94509 in 283823 gastric mucosal specimens, with an infection rate of 33.30%. The infection rate increased with age, and males had a higher infection rate than females. The average resistance rate of H. pylori to amoxicillin and metronidazole was 0.21% and 93.72%, which remained stable. The average resistance rate to clarithromycin was 23.99% with an increasing trend from 14.43% to 38.24%. The average resistance rate to levofloxacin was 30.29%, which increased from 17.07% to 39.42% and mostly stabilized after 2017. The resistance rate of H. pylori increased with age, except amoxicillin. H. pylori in females are at higher risk of resistance to metronidazole, but not to amoxicillin, regardless of the age group. Meanwhile, H. pylori in females are at higher risk of resistance to levofloxacin and clarithromycin in the 21-50 age group. The single, dual, triple and quadruple-drug resistance rate was 54.59%, 29.03%, 11.71% and 0.11%, respectively.

CONCLUSION

The resistance of H. pylori in Taizhou city is serious. Guided by the consensus report, individualized treatment based on AST is recommended.

Increasing Helicobacter pylori clarithromycin resistance in Australia over 20 years

OBJECTIVES

Helicobacter pylori infection is responsible for considerable morbidity and mortality worldwide, and eradication rates are falling in many countries, primarily due to clarithromycin and metronidazole resistance. However, there is a paucity of contemporary Australian data, which we sought to address by evaluating local rates of resistance of H. pylori to amoxicillin, clarithromycin, metronidazole, and tetracycline over the past 20 years.

DESIGN

All gastric biopsy specimens collected at endoscopy to detect H. pylori infection at a single centre underwent routine culture and antibiotic susceptibility testing between 1998-2017. Specimens from 12,842 patients were cultured for H. pylori, of which 1,473 positive cultures were tested for antibiotic susceptibility.

RESULTS

Antibiotic resistance to clarithromycin increased by 3.7% per year (IRR 1.037, p=0.014) over 20 years, with a corresponding 5.0% annual increase in minimum inhibitory concentration (MIC) (OR 1.050, p<0.001). Since 2010, average clarithromycin resistance has exceeded 20%, with >25% of isolates resistant in the last 2 years of data capture. By contrast, rates of resistance to metronidazole (35.3%), amoxicillin (0.14%) and tetracycline (0.34%) and their MICs have remained stable. Review of a representative sample of these patients (n=120, 8%) revealed that only 5% had documented prior H. pylori eradication therapy.

CONCLUSIONS

Over the last 20 years there has been a substantial rise in clarithromycin resistance, with stable metronidazole resistance and low rates of resistance to amoxicillin and tetracycline. Current first line H. pylori eradication therapy may fail to achieve adequate eradication rates, and optimal first line therapy in Australia should be revisited. This article is protected by copyright. All rights reserved.

The Efficacy of Probiotics in the Management of Helicobacter Pylori: A Systematic Review

Helicobacter pylori is a Gram-negative microorganism that causes chronic dyspepsia, gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma. Various antibiotic regimens are employed to eradicate it; however, antibiotic resistance has skyrocketed in recent years, resulting in a reduction in eradication rates. As a result, numerous novel therapeutic approaches are being adopted in clinical practice, and probiotics are being extensively investigated. Probiotics are living bacteria that, when consumed, offer many medicinal advantages that may be accomplished by altering the amount or activity of gut flora. Their beneficial influence on gut health, immune system modulation, and cancer therapy is the subject of extensive investigation. This is owing to their perceived safety and simplicity of use. The primary objective of this review is to learn about and investigate the function of probiotics in the eradication of H. pylori, either alone or in conjunction with traditional treatments.

Data have been collected from PubMed, PubMed Central, Medline, Cochrane, and Google Scholar, and relevant articles have been chosen following the PRISMA guidelines. Our search resulted in 2489 records, of which 123 full-text articles were screened for eligibility. Two reviewers independently performed the quality appraisal of 16 relevant articles, and ultimately 11 high-quality studies are included in this review. In conclusion, probiotic monotherapy does not have a significant effect on the eradication rates of H. pylori, but in conjunction with standard treatment regimens, there was mild improvement in the eradication rates but a significant reduction of side effects due to antibiotics.

Treatment of Helicobacter pylori infection in the presence of penicillin allergy

Therapy of Helicobacter pylori (H.pylori) requires a combination of antibiotics together with an acid suppressing agent; most treatment regimens include Amoxicillin as one of the antibiotics, which is an important constituent as resistance to it is low. However, allergies to the penicillin group of antibiotics are not uncommon, and treating H.pylori infection in such individuals can be challenging due to the restricted choice of regimens. The aim of this review is to summarise the evidence for therapeutic options in patients with H.pylori infection and penicillin allergy. A literature search was conducted in PubMed for English language publications using the key words ‘Helicobacter’ and ‘treatment’ or ‘therapy‘ and ‘penicillin’ or ‘beta-lactam’ and ‘allergy’ or ‘anaphylaxis’. Eighteen studies were identified that specifically evaluated H.pylori treatment success in penicillin allergic patients. The number of subjects in most of them was low and many were retrospective, uncontrolled, single cohort studies. The most effective option for first-line treatment appears to be Bismuth-based quadruple therapy for 10-14 d. The evidence supports second-line treatment with Levoflaxacin-based triple therapy for 10 d. Patients with persistent H.pylori infection after 2 treatment courses should be considered for testing to confirm penicillin allergy. Further treatment should be guided by the results of H.pylori culture and sensitivity testing.

Tailored susceptibility-guided therapy via gastric juice PCR for the first-line H. pylori eradication, a randomized controlled trial

BACKGROUND/PURPOSE

Clarithromycin-based standard triple therapy is still commonly adopted by 81.4% of physicians in real-world practice but yields low eradication rates. Therefore, we conducted this study to compare the efficacy of gastric juice-guided therapy for first-line eradication with the standard triple therapy, in order to provide an alternative to real-world practice.

METHODS

A total of 182 treatment-naïve Hp-infected patients were included and randomly allocated to either susceptibility-guided therapy (SGT) with gastric juice PCR or Clarithromycin-based standard triple therapy (STT) for 7 days.

RESULTS

The intention-to-treat eradication rates were 89% (81/91) in SGT and 75.8% in STT (p < 0.031). The per-protocol eradication rates were 91.0% (81/89) in SGT and 79.3% (69/87) in STT (p < 0.034). Among the subgroups of different antibiotic resistance, patients with SGT demonstrated superior eradication rates (91.7% vs 45.5%, p < 0.027) in the subgroup of both clarithromycin resistance and levofloxacin resistance.

CONCLUSION

This prospective randomized controlled trial demonstrated the reliable efficacy of susceptibility-guided therapy via gastric juice PCR for the first-line Hp eradication. In Asia-Pacific area, where standard triple therapy is still adopted by the majority of the physicians, it is a recommended alternative to overcome the increasing antibiotic resistance.