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

Extent of Virulence and Antibiotic Resistance Genes in Helicobacter pylori and Campylobacteria

Helicobacter pylori, a member of the clade campylobacteria, is the leading cause of chronic gastritis and gastric cancer. Virulence and antibiotic resistance of H. pylori are of great concern to public health. However, the relationship between virulence and antibiotic resistance genes in H. pylori in relation to other campylobacteria remains unclear. Using the virulence and comprehensive antibiotic resistance databases, we explored all available 354 complete genomes of H. pylori and compared it with 90 species of campylobacteria for virulence and antibiotic resistance genes/proteins. On average, H. pylori had 129 virulence genes, highest among Helicobacter spp. and 71 antibiotic resistance genes, one of the lowest among campylobacteria. Just 2.6% of virulence genes were shared by all campylobacterial members, whereas 9.4% were unique to H. pylori. The cytotoxin-associated genes (cags) seemed to be exclusive to H. pylori. Majority of the isolates from Asia and South America were cag2-negative and many antibiotic resistance genes showed isolate-specific patterns of occurrence. Just 15 (8.8%) antibiotic resistance genes, but 103 (66%) virulence genes including 25 cags were proteomically identified in H. pylori. Arcobacterial members showed large variation in the number of antibiotic resistance genes and there was a positive relation with the genome size. Large repository of antibiotic resistance genes in campylobacteria and a unique set of virulence genes might have important implications in shaping the course of virulence and antibiotic resistance in H. pylori.

Antibiotic-induced ROS-mediated Fur allosterism contributes to Helicobacter pylori resistance by inhibiting arsR activation of mutS and mutY

The increasing antibiotic resistance of Helicobacter pylori primarily driven by genetic mutations poses a significant clinical challenge. Although previous research has suggested that antibiotics could induce genetic mutations in H. pylori, the molecular mechanisms regulating the antibiotic induction remain unclear. In this study, we applied various techniques (e.g., fluorescence microscopy, flow cytometry, and multifunctional microplate reader) to discover that three different types of antibiotics could induce the intracellular generation of reactive oxygen species (ROS) in H. pylori. It is well known that ROS, a critical factor contributing to bacterial drug resistance, not only induces damage to bacterial genomic DNA but also inhibits the expression of genes associated with DNA damage repair, thereby increasing the mutation rate of bacterial genes and leading to drug resistance. However, further research is needed to explore the molecular mechanisms underlying the ROS inhibition of the expression of DNA damage repair-related genes in H. pylori. In this work, we validated that ROS could trigger an allosteric change in the iron uptake regulatory protein Fur, causing its transition from apo-Fur to holo-Fur, repressing the expression of the regulatory protein ArsR, ultimately causing the down-regulation of key DNA damage repair genes (e.g., mutS and mutY); this cascade increased the genomic DNA mutation rate in H. pylori. This study unveils a novel mechanism of antibiotic-induced resistance in H. pylori, providing crucial insights for the prevention and control of antibiotic resistance in H. pylori.

Tumor-infiltrating mast cells stimulate ICOS+ regulatory T cells through an IL-33 and IL-2 axis to promote gastric cancer progression

INTRODUCTION

In solid tumors, regulatory T cell (Treg) and mast cell perform different roles depending on the microenvironment. Nevertheless, mast cell and Treg-mediated interactions in gastric cancer (GC) are unclear, as are their regulation, function, and clinical significance.

OBJECTIVE

The present study demonstrated the mechanism of tumor-infiltrating mast cells stimulating ICOS+ regulatory T cells via the IL-33/IL-2 axis to promote the growth of gastric cancer.

METHODS

Analyses of 98 patients with GC were conducted to examine mast cell counts, ICOS+ Tregs, and the levels of IL-33 or IL-2. Isolated ICOS+ Treg and CD8+ T cell were stimulated, cultured and tested for their functional abilities in vitro and in vivo.

RESULTS

GC patients exhibited a significantly more production of IL-33 in tumors. Mast cell stimulated by tumor-derived IL-33 exhibited a prolonged lifespan through IL-33 mediated inhibition of apoptosis. Moreover, mast cells stimulated by tumor-derived IL-33 secreted IL-2, which induced Treg expansion. These inducible Tregs displayed an activated immunosuppressive phenotype with positive expression for the inducible T cell co-stimulator (ICOS). In vitro, IL-2 from IL to 33-stimulated mast cells induced increased numbers of ICOS+ Tregs with increased immunosuppressive activity against proliferation and effector function of CD8+ T cell. In vivo, ICOS+ Tregs were treated with anti-IL-2 neutralizing antibody followed by co-injection with CD8+ T cells in GC mouse model, which showed an increased CD8+ T cell infiltration and effector molecules production, meanwhile tumor growth and progression were inhibited. Besides, reduction in GC patient survival was associated with tumor-derived ICOS+ Tregs.

CONCLUSION

Our results highlight a crosstalk between GC-infiltrating mast cells and ICOS+ Tregs and provide a novel mechanism describing ICOS+ Treg expansion and induction by an IL-33/mast cell/IL-2 signaling axis in GC, and also provide functional evidence that the modulation of this immunosuppressive pathway can attenuate GC-mediated immune tolerance.

Role of proton pump inhibitors dosage and duration in Helicobacter pylori eradication treatment: Results from the European Registry on H. pylori management

BACKGROUND

Management of Helicobacter pylori (H. pylori) infection requires co-treatment with proton pump inhibitors (PPIs) and the use of antibiotics to achieve successful eradication.

AIM

To evaluate the role of dosage of PPIs and the duration of therapy in the effectiveness of H. pylori eradication treatments based on the 'European Registry on Helicobacter pylori management' (Hp-EuReg).

METHODS

Hp-EuReg is a multicentre, prospective, non-interventionist, international registry on the routine clinical practice of H. pylori management by European gastroenterologists. All infected adult patients were systematically registered from 2013 to 2022.

RESULTS

Overall, 36,579 patients from five countries with more than 1000 patients were analysed. Optimal (≥90%) first-line-modified intention-to-treat effectiveness was achieved with the following treatments: (1) 14-day therapies with clarithromycin-amoxicillin-bismuth and metronidazole-tetracycline-bismuth, both independently of the PPI dose prescribed; (2) All 10-day (except 10-day standard triple therapy) and 14-day therapies with high-dose PPIs; and (3) 10-day quadruple therapies with clarithromycin-amoxicillin-bismuth, metronidazole-tetracycline-bismuth, and clarithromycin-amoxicillin-metronidazole (sequential), all with standard-dose PPIs. In first-line treatment, optimal effectiveness was obtained with high-dose PPIs in all 14-day treatments, in 10- and 14-day bismuth quadruple therapies and in 10-day sequential with standard-dose PPIs. Optimal second-line effectiveness was achieved with (1) metronidazole-tetracycline-bismuth quadruple therapy for 14- and 10 days with standard and high-dose PPIs, respectively; and (2) levofloxacin-amoxicillin triple therapy for 14 days with high-dose PPIs. None of the 7-day therapies in both treatment lines achieved optimal effectiveness.

CONCLUSIONS

We recommend, in first-line treatment, the use of high-dose PPIs in 14-day triple therapy and in 10-or 14-day quadruple concomitant therapy in first-line treatment, while standard-dose PPIs would be sufficient in 10-day bismuth quadruple therapies. On the other hand, in second-line treatment, high-dose PPIs would be more beneficial in 14-day triple therapy with levofloxacin and amoxicillin or in 10-day bismuth quadruple therapy either as a three-in-one single capsule or in the traditional scheme.

In vitro anti-bactrical activity and its preliminary mechanism of action of the non-medicinal parts of Sanguisorba officinalis L. against Helicobacter pylori infection

ETHNOPHARMACOLOGICAL RELEVANCE

Sanguisorba officinalis L. (S. officinalis L.), known as Di Yu (DY) in Traditional Chinese Medicine (TCM), are used to treat burns, vomiting of blood, asthma, intestinal infections, and dermatitis. It has been reported that the root of DY has a significant inhibitory effect on Helicobacter pylori (H. pylori). However, there is currently little research on the composition analysis and anti-H. pylori infection properties of the non-medicinal parts of DY, such as its stems, leaves, and flowers.

AIM OF STUDY

The commonly used eradication therapies for H. pylori infection are antibiotic-based therapies. With the increasing antibiotic resistance of H. pylori, it is urgent to find effective alternative therapies. To find alternative therapies and increase the utilization of DY, this study aims to investigate the phytochemistry profile, in vitro anti-H. pylori activity, and preliminary antibacterial mechanism of the non-medicinal parts of DY.

MATERIALS AND METHODS

The non-medicinal parts of DY extracts were obtained by using hot water reflux method. The chemical composition of these extracts was analyzed using colorimetric method, high-performance liquid chromatography (HPLC), and ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). The in vitro anti-H. pylori activity was investigated using broth microdilution method, checkerboard dilution method, time-kill curve, time-inhibition curve, scanning electron microscopy, and transmission electron microscopy. Transcriptional sequencing technology was used to study the effect of DY stems and flowers on the gene expression of H. pylori and explore possible antibacterial mechanisms.

RESULTS

The non-medicinal parts of DY contain abundant phytochemicals, such as total phenols and total flavonoids, and possess strong inhibitory and bactericidal activity against both standard and clinical strains of H. pylori in vitro. The MIC was 80-1280 μg/mL and the MBC was 80-2560 μg/mL, and the strength of the antibacterial effects was dependent on the concentration of phytochemicals (total polyphenols, gallic acid and ellagic acid). In addition, the combination of non-medicinal parts of DY with antibiotics, such as amoxicillin, metronidazole, levofloxacin, and clarithromycin, did not result in any antagonistic effects. All of them could disrupt the morphology, internal microscopic and cell wall structures of H. pylori thereby acting as an inhibitor. The mechanism of action was found to be the disruption of H. pylori morphology, internal microstructure, and cell wall. Transcriptomic analysis showed that the non-medicinal parts of DY significantly regulated the gene expression of H. pylori, especially the metabolic pathway.

CONCLUSIONS

This study analyzed the chemical composition of the non-medicinal parts of DY and confirmed its inhibitory and bactericidal activities against H. pylori, both standard and clinical strains. Additional, the mechanism of inhibition involves disrupting the structure of H. pylori cells, altering gene expression, and interfering with bacterial metabolic pathways. This study provides a reference for further resource utilization and the development of H. pylori drugs using the non-medicinal parts of DY.

Study of Helicobacter pylori Isolated from a High-Gastric-Cancer-Risk Population: Unveiling the Comprehensive Analysis of Virulence-Associated Genes including Secretion Systems, and Genome-Wide Association Study

BACKGROUND

The prevalence of gastric cancer in Mongolia, in East Asia, remains the highest in the world. However, most Helicobacter pylori strains in Mongolia have a less virulent Western-type CagA. We aimed to determine how H. pylori genomic variation affected gastric diseases, especially gastric cancer, based on comprehensive genome analysis.

METHODS

We identified a set of 274 virulence-associated genes in H. pylori, including virulence factor and outer membrane protein (OMP) genes, the type four secretion system gene cluster, and 13 well-known virulence gene genotypes in 223 H. pylori strains and their associations with gastric cancer and other gastric diseases. We conducted a genome-wide association study on 158 H. pylori strains (15 gastric cancer and 143 non-gastric cancer strains).

RESULTS

Out of 274 genes, we found 13 genes were variable depending on disease outcome, especially iron regulating OMP genes. H. pylori strains from Mongolia were divided into two main subgroups: subgroup (Sg1) with high risk and Sg2 with low risk for gastric cancer. The general characteristics of Sg1 strains are that they possess more virulence genotype genes. We found nine non-synonymous single nucleotide polymorphisms in seven genes that are linked with gastric cancer strains.

CONCLUSIONS

Highly virulent H. pylori strains may adapt through host-influenced genomic variations, potentially impacting gastric carcinogenesis.

Linolenic acid-metronidazole inhibits the growth of Helicobacter pylori through oxidation

BACKGROUND

Resistance to antibiotics is one the main factors constraining the treatment and control of Helicobacter pylori (H. pylori) infections. Therefore, there is an urgent need to develop new antimicrobial agents to replace antibiotics. Our previous study found that linolenic acid-metronidazole (Lla-Met) has a good antibacterial effect against H. pylori, both antibiotic-resistant and sensitive H. pylori. Also, H. pylori does not develop resistance to Lla-Met. Therefore, it could be used for preparing broad-spectrum antibacterial agents. However, since the antibacterial mechanism of Lla-Met is not well understood, we explored this phenomenon in the present study.

AIM

To understand the antimicrobial effect of Lla-Met and how this could be applied in treating corresponding infections.

METHODS

H. pylori cells were treated with the Lla-Met compound, and the effect of the compound on the cell morphology, cell membrane permeability, and oxidation of the bacteria cell was assessed. Meanwhile, the differently expressed genes in H. pylori in response to Lla-Met treatment were identified.

RESULTS

Lla-Met treatment induced several changes in H. pylori cells, including roughening and swelling. In vivo experiments revealed that Lla-Met induced oxidation, DNA fragmentation, and phosphatidylserine ectropionation in H. pylori cells. Inhibiting Lla-Met with L-cysteine abrogated the above phenomena. Transcriptome analysis revealed that Lla-Met treatment up-regulated the expression of superoxide dismutase SodB and MdaB genes, both anti-oxidation-related genes.

CONCLUSION

Lla-Met kills H. pylori mainly by inducing oxidative stress, DNA damage, phosphatidylserine ectropionation, and changes on cell morphology.

Lactobacillus acidophilus NCFM and Lactiplantibacillus plantarum Lp-115 inhibit Helicobacter pylori colonization and gastric inflammation in a murine model

Purpose

To determine the role of Lactobacillus strains and their combinations in inhibiting the colonization of H. pylori and gastric mucosa inflammation.

Methods

Human gastric adenocarcinoma AGS cells were incubated with H. pylori and six probiotic strains (Lactobacillus acidophilus NCFM, L. acidophilus La-14, Lactiplantibacillus plantarum Lp-115, Lacticaseibacillus paracasei Lpc-37, Lacticaseibacillus rhamnosus Lr-32, and L. rhamnosus GG) and the adhesion ability of H. pylori in different combinations was evaluated by fluorescence microscopy and urease activity assay. Male C57BL/6 mice were randomly divided into five groups (uninfected, H. pylori, H. pylori+NCFM, H. pylori+Lp-115, and H. pylori+NCFM+Lp-115) and treated with two lactobacilli strains (NCFM and Lp-115) for six weeks. H. pylori colonization and tissue inflammation statuses were determined by rapid urease test, Hematoxylin-Eosin (HE) staining, immunohistochemistry, and qRT-PCR and ELISA.

Results

L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, L. paracasei Lpc-37, L. rhamnosus Lr-32, and L. rhamnosus GG reduced H. pylori adhesion and inflammation caused by H. pylori infection in AGS cells and mice. Among all probiotics L. acidophilus NCFM and L. plantarum, Lp-115 showed significant effects on the H. pylori eradication and reduction of inflammation in-vitro and in-vivo. Compared with the H. pylori infection group, the mRNA and protein expression levels of IL-8 and TNF-α in the six Lactobacillus intervention groups were significantly reduced. The changes in the urease activity (ureA and ureB) for 1-7h in each group showed that L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, and L. rhamnosus GG effectively reduced the colonization of H. pylori. We observed a higher ratio of lymphocyte and plasma cell infiltration into the lamina propria of the gastric mucosa and neutrophil infiltration in H. pylori+NCFM+Lp-115 mice. The infiltration of inflammatory cells in lamina propria of the gastric mucosa was reduced in the H. pylori+NCFM+Lp-115 group. Additionally, the expression of IFN-γ was decreased significantly in the NCFM and Lp-115 treated C57BL/6 mice.

Conclusions

L. acidophilus NCFM and L. plantarum Lp-115 can reduce the adhesion of H. pylori and inhibit the gastric inflammatory response caused by H. pylori infection.

Preparation of Corn Peptides with Anti-Adhesive Activity and Its Functionality to Alleviate Gastric Injury Induced by Helicobacter pylori Infection In Vivo

More than 50% of the world population is infected with Helicobacter pylori (H. pylori), which is classified as group I carcinogen by the WHO. H. pylori surface adhesins specifically recognize gastric mucosal epithelial cells' (GES-1 cells) receptor to complete the adhesion. Blocking the adhesion with an anti-adhesion compound is an effective way to prevent H. pylori infection. The present study found that corn protein hydrolysate, hydrolyzed by Neutral, effectively alleviated gastric injury induced by H. pylori infection through anti-adhesive and anti-inflammatory effects in vitro and in vivo. The hydrolysate inhibited H. pylori adhesion to GES-1 cells significantly, and its anti-adhesive activity was 50.44 ± 0.27% at 4 mg/mL, which indicated that the hydrolysate possessed a similar structure to the GES-1 cells' receptor, and exhibited anti-adhesive activity in binding to H. pylori. In vivo, compared with the H. pylori infection model group, the medium and high dose of the hydrolysate (400-600 mg/kg·bw) significantly decreased (p < 0.05) the amount of H. pylori colonization, pro-inflammatory cytokines (IL-6, IL-1β, TNF-α and MPO), chemokines (KC and MCP-1) as well as key metabolites of NF-κB signaling pathway levels (TLR4, MyD88 and NF-κB), and it increased antioxidant enzyme contents (SOD and GSH-Px) and the mitigation of H. pylori-induced pathological changes in the gastric mucosa. Taken together, these results indicated that the hydrolysate intervention can prevent H. pylori-induced gastric injury by anti-adhesive activity and inhibiting the NF-κB signaling pathway's induction of inflammation. Hence, the corn protein hydrolysate might act as a potential anti-adhesive agent to prevent H. pylori infection.

Prevalence of Helicobacter pylori Antibiotic Resistance in Patients Enrolled in Guangzhou, China

PURPOSE

Helicobacter pylori (H. pylori) infection is a high-risk factor for the occurrence of gastric cancer. The quadruple therapy has been widely used as the first-line treatment for H. pylori in China. However, the increasing resistance rate to antibiotics has become a major challenge in the treatment of H. pylori. Therefore, there is an urgent need for rapid and cost-effective detection of antibiotic resistance to different antibiotics. To evaluate the prevalence of H. pylori antibiotic resistance in Guangzhou and the diagnostic performance of DOB value of 13C UBT in predicting antibiotic resistance.

PATIENTS AND METHODS

In this retrospective study, we collected data from 193 H. pylori culture-positive patients in Guangzhou on their DOB values and resistance to antibiotics. We analyzed the antibiotic resistance rate of commonly used antibiotics in quadruple therapy, and the diagnostic efficacy of DOB value was evaluated.

RESULTS

The resistance rates of clarithromycin (CLA) and levofloxacin (LEV) were 46.1% and 44.0%, respectively. In the age group under 40, the resistance rate of LEV was lower than that of CLA. However, the diagnostic efficacy of DOB value was found to be low and it could not serve as an independent indicator for diagnosing resistance to CLA and LEV.

CONCLUSION

The high resistance rates of CLA and LEV in H. pylori patients in Guangzhou indicate the urgent need for effective detection methods. The DOB value is not a direct indicator of antibiotic resistance to CLA and LEV. Therefore, it is important to use a combination of diagnostic methods to accurately assess antibiotic resistance in H. pylori infection.

Epidemiology of Helicobacter pylori Resistance to Antibiotics (A Narrative Review)

Helicobacter pylori (H. pylori) is the most common bacterial infection worldwide and one of the main etiological factors of chronic gastritis, peptic ulcer disease, and stomach neoplasms. The mass application of antibiotics without testing, especially during the last years of the pandemic of SARS-CoV-2, could lead to a dramatic increase in antibiotic resistance and reduced effectiveness of eradication regimens for H. pylori infection. The epidemiology of H. pylori resistance to antibiotics still has unclear mechanisms. Antibiotic policy should be intensified to optimize treatment, and regular monitoring of resistance of H. pylori in different geographical regions should be conducted. Individualized treatment according to susceptibility testing is strongly advisable, and the best treatment regimens should be selected. The mutations in the genes encoding the antibiotic target protein are significant risk factors for H. pylori resistance. Iatrogenic errors in diagnosis and prescribing treatment for the failure of H. pylori eradication are other important risk factors. The low level of awareness and compliance with the correct treatment influence the rate of H. pylori resistance. Epidemiological surveillance of antibiotic resistance and the adoption of new treatment strategies are needed. The discovery of an efficient vaccine against H. pylori could reduce the pressure of the world's growing antibiotic resistance.

Effectiveness of eradication therapy for Helicobacter pylori infection in Africa: a systematic review and meta-analysis

BACKGROUND

The effectiveness of Helicobacter pylori (H. pylori) eradication depends on the treatment protocol. This study investigates the H. pylori eradication rate in Africa using the best available evidence from databases.

METHODS

Databases were searched and results were pooled together. Heterogeneity between studies was assessed using I² test statistics. Stata version 13 software was employed to compute the pooled eradication rate. In the subgroup analysis comparison, the finding is considered significant when the confidence intervals did not overlap.

RESULTS

Twenty-two studies from 9 African countries with a total population of 2,163 were included in this study. The pooled eradication rate of H. pylori was 79% (95% CI: 75%-82%), heterogeneity (I² = 93.02%). In the subgroup analysis by study design, a higher eradication rate was reported from observational studies (85%, 95% CI: 79%-90%), compared to randomized control trials (77%, 95% CI: 73%-82%); by the duration of therapy, higher eradication rate was reported in 10-days regimen (88%, 95% CI: 84%-92%), compared to 7-days regimen (66%, 95% CI: 55%-77%); by country, the highest eradication rate was found in Ethiopia (90%; 95% CI: 87%-93%) and the lowest eradication rate was reported in Ivory Coast (22.3%; 95% CI:15%-29%); by type of H. pylori test, the highest eradication rate was reported when rapid urease test coupled with histology (88%, 95% CI: 77%-96%), and the lowest eradication rate was reported with histology alone (22.3%; 95% CI:15%-29%). Significant heterogeneity was observed with pooled prevalence (I² = 93.02%, P < 0.000).

CONCLUSIONS

In Africa, the first-line therapy showed a variable eradication rate for H. pylori. This study demonstrates the necessity to optimize current H. pylori treatment regimens in each country, taking into account the antibiotic susceptibility. Future RCT studies with standardized regimens are warranted.

From Antibiotic Resistance to Antibiotic Renaissance: A New Era in Helicobacter pylori Treatment

Helicobacter pylori (H. pylori) is a common bacterial infection that can cause gastric diseases, including gastric cancer. The standard treatment for H. pylori infection is a combination of antibiotics and acid suppressants, but antibiotic resistance has become a significant problem that can reduce treatment efficacy. The development of novel treatment strategies for H. pylori is necessary to reduce the burden of this infection on public health. This review article examines H. pylori antibiotic resistance and future treatment possibilities. We discuss transitioning from trial and error to antimicrobial stewardship and using multi-strain probiotics as an adjunct therapy for H. pylori eradication. This review article provides an extensive overview of H. pylori antibiotic resistance and future treatment possibilities. It begins with an introduction and background of the topic, followed by a literature review. The review of the literature covers the transition from trial and error to antimicrobial stewardship, the diagnosis and treatment of H. pylori, the comparative effectiveness of multiple first-line treatment regimens, the ideal H. pylori treatment for the present and future, the use of probiotics to reduce adverse events and improve eradication rates, and the use of novel and effective therapeutic regimens in an era of increasing antibiotic resistance. The conclusion summarizes the review's findings and provides recommendations for future research. The terms Helicobacter pylori, infection, antibiotic resistance, clarithromycin, macrolide resistance, proton pump inhibitors, vonoprazan, triple regimen, susceptibility, and stewardship were used in a PubMed literature search. Finally, the article highlights the urgent need for a global collaborative approach toward tackling antibiotic resistance in H. pylori infections.

DEVELOPMENT OF APIGENIN LOADED GASTRORETENTIVE MICROSPONGE FOR THE TARGETING OF HELICO BACTER PYLORI

The goal of the present work was to invent an apigenin-stacked gastroretentive microsponge to target H. pylori. The quasi-emulsion technique was used to prepare microsponges, which were then tested for various physicochemical properties, in-vivo gastric retention, and in-vitro anti-H. pylori study. The microsponge that demonstrated a comparatively good product yield (76.23 ± 0.84), excellent entrapment efficiency (97.84 ± 0.85), sustained in-vitro gastric retention period, and prolonged drug release were chosen for further investigations. The microsponge's SEM analysis showed that it had a spherical form, porous surface, and interconnected spaces. No drug-polymer interactions were detected in the FTIR investigation. Apigenin was found to be dispersed in the microsponge's polymeric matrix according to DSC & XRD investigations. Moreover, the microsponge in the rat's stomach floated for 4 h, according to the ultrasonography. The antibacterial activity of apigenin against H. pylori was nearly two folds more than the pure apigenin and had a more sustained release in the best microsponge, according to the in vitro MIC data, when compared to pure apigenin. To sum up, the developed gastroretentive microsponge with apigenin offers a viable alternative for the efficient targeting of H. pylori. But more preclinical & clinical studies of our best microsponge would yield considerably more fruitful results.

Effectiveness of 7-day triple therapy with half-dose clarithromycin for the eradication of Helicobacter pylori without the A2143G and A2142G point mutations of the 23S rRNA gene in a high clarithromycin resistance area

Background

Tailored therapy has been widely used for patients with Helicobacter pylori (H. pylori) infection in South Korea. Herein, we evaluated the treatment outcomes of tailored clarithromycin-based triple therapy (TT) in patients infected with H. pylori.

Methods

We enrolled 460 patients without A2142G and A2143G point mutations by dual priming oligonucleotide-based polymerase chain reaction who had taken TT and undergone the urease breath test to evaluate eradication in clinical practice. Eradication rates according to the treatment duration and dose of clarithromycin were analyzed.

Results

Among 460 patients (164 women, median age 63.0 years), 250 patients underwent TT with full-dose clarithromycin (TT-full CLA), and 216 patients underwent TT with half-dose clarithromycin (TT-half CLA). The eradication rates were 88.0% (220/250) in patients with TT-full CLA and 85.2% (179/210) in patients with TT-half CLA. In 250 patients with TT-full CLA, the eradication rates were 86.8% (33/38) in patients with 7-day TT-full CLA and 88.2% (187/212) in patients with 10-day or 14-day TT-full CLA (P = 0.788). In 210 patients with TT-half CLA, the eradication rates were 84.2% (139/165) in those with a 7-day TT-half CLA and 88.9% (40/45) in those with a 10-day or 14-day TT-half CLA (P = 0.436).

Conclusion

For patients with H. pylori infection without A2142G and A2143G point mutations by DPO-PCR in clinical practice, treatment extension above 7-day TT with full CLA did not improve the eradication rates. Future studies on the treatment outcomes of TT-half CLA considering effectiveness and compliance are warranted.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy of Н. pylori infection.

Key points. Chronic gastritis caused by Н. pylori infection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include 13C-urea breath test, H. pylori stool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In Russia H. pylori strains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy for Н. pylori infection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case of H. pylori infection the decision for eradication therapy should be made, which is especially relevant as eradication of H. pylori has been recognized as an effective measure for the prevention of gastric cancer.

Clinical Practice Guidelines of Russian Gastroenterological Association, Scientific Society for the Clinical Study of Human Microbiome, Russian Society for the Prevention of Non-Communicable Diseases, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy for <i>H. pylori</i> Diagnostics and Treatment in Adults

Aim: bring to the attention of practitioners indications for anti-Helicobacter therapy, methods and procedure for diagnostics and eradication therapy of Н. pylori infection.

Key points. Chronic gastritis caused by Н. pylori infection, including asymptomatic persons, may be considered as an indication for eradication therapy of Н. pylori as etiological therapy and opportunistic screening for gastric cancer prevention. Indications, for obligatory anti-Helicobacter therapy include peptic ulcer, gastric MALT lymphoma, early gastric cancer (EGC) with endoscopic resection. H. pylori primary diagnostics methods include 13C-urea breath test, H. pylori stool antigen lab test, rapid urease test and serological method. The serological method cannot be used after anti-Helicobacter therapy.

In Russia H. pylori strains' resistance to clarithromycin does not exceed 15 % in most regional studies. The first line therapy for Н. pylori infection eradication is the standard triple therapy including a proton pump inhibitor (PPI), clarithromycin and amoxicillin, enhanced with bismuthate tripotassium dicitrate. A classic four-component therapy based on bismuthate tripotassium dicitrate or quadrotherapy without bismuth drug products which includes PPI, amoxicillin, clarithromycin and metronidazole, may be used as alternative to the first line eradication therapy. The standard triple therapy may be prescribed for 14 days only in those regions, where it has been proven to be effective. Quadrotherapy with bismuthate tripotassium dicitrate is also used as main second line therapy in case of standard triple therapy, bismuth enhanced standard triple therapy or combined therapy failure. Another second line therapy includes PPI, levofloxacin and amoxicillin, to which a bismuth-containing drug product may be added. The third line therapy is selected individually based on previously used treatment settings.

Conclusion. In each case of H. pylori infection the decision for eradication therapy should be made, which is especially relevant as eradication of H. pylori has been recognized as an effective measure for the prevention of gastric cancer.

The Importance of Accurate Early Diagnosis and Eradication in Helicobacter pylori Infection: Pictorial Summary Review in Children and Adults

Among the most widespread childhood infections, Helicobacter pylori (H. pylori) develops potentially life-threatening conditions in adults if not appropriately treated. Helicobacter pylori is a common human pathogen that was first described in the stomach many years ago. The discovery of H. pylori was crucial in gastroenterology; this bacterium is associated with chronic gastritis, peptic ulcers, gastric cancer, and lymphoid tissue lymphoma related to the gastric mucosa. Studies published so far estimate that approximately 10% of subjects infected with H. pylori develop a peptic ulcer, and 1-3% of subjects develop gastric cancer. The clinical manifestations are variable and characteristically depend on the individual factors of the host. Various methods of detection and diagnosis of H. pylori infection have been developed, each with advantages, disadvantages, and/or limitations. Available diagnostic tests are usually performed using invasive (endoscopy, biopsy, rapid urease test, cultures, and molecular tests) and noninvasive methods (urea breath test, stool antigen examination, and serological and molecular tests). Although there is extensive accessibility for diagnosing and treating H. pylori infection, the prevalence of antibiotic resistance is not negligible. Thus, numerous studies and meta-analyses are focused on a new orientation of gastroenterologists in diagnosing and treating H. pylori infections. A fascinating perspective hypothesis is the administration of probiotics to reduce H. pylori adhesion to gastric epithelial cells, preventing H. pylori colonization, especially in children, or reinfection with H. pylori in high-risk adult patients.

Treatment strategies and pharmacist-led medication management for Helicobacter pylori infection

Half of the world's population is Helicobacter pylori carrier. Updated guidelines and consensus have been issued across regions with the main aim of reducing social transmission and increasing H. pylori eradication rate. Although alternative therapies including traditional Chinese medicine and probiotics have also been used to improve H. pylori eradication rate in clinical practice, current mainstream treatment is still dependent on triple and quadruple therapies that includes antibacterial agents (e.g., amoxicillin and furazolidone) and proton pump inhibitor. Researches also assessed the eradication rate of optimized high-dose dual therapy in treating H. pylori infection. With the increase of antibiotic resistance rate, the treatment strategies for H. pylori infection are constantly adjusted and improved. Besides, low medication compliance is another key influencing factor for H. pylori treatment failure. Emerging studies indicate that pharmacists' intervention and new pharmaceutical care methods can enhance patient medication compliance, reduce adverse drug reactions, and improve H. pylori eradication rate. The purpose of this review is to summarize the advances in treating H. pylori infection and highlight the necessity of developing novel strategies to cope with the increasing challenges and to achieve personalized medication. Also, this review attaches great importance to pharmacists in optimizing H. pylori treatment outcomes as a routine part of therapy.

The management of Helicobacter pylori infection and prevention and control of gastric cancer in China

Helicobacter pylori (H. pylori) infection, a type-1 carcinogen, was closely associated with gastric cancer (GC). Successfully eradicating H. pylori infection could reduce the incidence of GC. China was a country with high incidence of GC and high prevalence of H. pylori infection. Nearly half of worldwide GC new cases and deaths attributed to H. pylori infection occurred in China. H. pylori prevalence varied over time with the improvement of socioeconomic status and sanitary conditions. The knowledge of antibiotic resistance rate in time was important to guide the clinical choice of antibiotics use in the regimens. With the publication of five Chinese consensus reports on the management of H. pylori infection and the effort of public preach of H. pylori-related knowledge, the standardization of H. pylori diagnosis and treatment by clinicians was improved. Bismuth-containing quadruple therapy was widely applied in clinical practice of H. pylori eradication because of high efficacy and safety. High-dose Proton Pump Inhibitor-amoxicillin dual therapy or vonoprazan-amoxicillin dual therapy showed comparable efficacy and lower side effects than bismuth-containing quadruple therapy, which were the alternative choice. The diagnosis rate of early GC was low and distinguishing Chinese GC risk population for the further endoscopy screening was important. Efforts have been done to establish prediction models to stratify GC risk in the Chinese GC risk population. We reviewed the current situation of the management of H. pylori infection and prevention and control of GC in China here.

Impact of insufficient doses of medications on Helicobacter pylori eradication: a retrospective observational study

BACKGROUND AND AIMS

The doses of medications may influence the success of Helicobacter pylori (H. pylori) eradication. This real-world observational study aimed to explore the impact of insufficient doses of medications prescribed for the bismuth-containing quadruple therapy (BQT) regimen on successful H. pylori eradication.

METHODS

We retrospectively screened the patients who were diagnosed with H. pylori infection and received BQT regimens for H. pylori eradication at our department between January 2017 and July 2020. The rate of successful H. pylori eradication was compared according to the doses of medications prescribed. Standard doses were defined according to the clinical guidelines.

RESULTS

Overall, 1054 patients were included. The rate of successful H. pylori eradication was 78.2% (824/1054). Among them, proton pump inhibitors (PPIs) and antibiotics were prescribed at insufficient doses in 37.0% (390/1054) and 6.7% (71/1054) of patients, respectively. Furthermore, pantoprazole (98.7% [385/390]) was the most common type of PPIs prescribed at insufficient doses, and nitroimidazoles (85.9% [61/71]) were the most common type of antibiotics prescribed at insufficient doses. Among the patients receiving colloidal bismuth pectin (CBP) (200mg tid) and standard-dose antibiotics, the rate of successful H. pylori eradication was lower in insufficient-dose PPIs group than standard-dose PPIs group (78.1% [271/347] versus 82.6% [438/530], P=0.095). Among the patients receiving CBP (200mg tid) and standard-dose PPIs, the rate of successful H. pylori eradication was significantly lower in insufficient-dose antibiotics group than standard-dose antibiotics group (37.8% [14/37] versus 82.6% [438/530], P<0.0001). Among the patients receiving CBP 200mg tid, the rate of successful H. pylori eradication was significantly lower in patients receiving both PPIs and antibiotics at insufficient doses than those at standard doses (46.4% [13/28] versus 82.6% [438/530], P<0.0001).

CONCLUSION

Among the BQT regimens, PPIs and/or antibiotics, especially pantoprazole and metronidazole, are often prescribed at insufficient doses, compromising the success of H. pylori eradication.

Helicobacter Pylori-Induced Gastric Infections: From Pathogenesis to Novel Therapeutic Approaches Using Silver Nanoparticles

Helicobacter pylori is the first formally recognized bacterial carcinogen and the most important single digestive pathogen responsible for the induction of gastroduodenal diseases such as gastritis, peptic ulcer, and, finally, gastric neoplasia. The recently reported high rates of antimicrobial drug resistance hamper the current therapies of H. pylori, with therapeutic failure reaching up to 40% of patients. In this context, new treatment options and strategies are urgently needed, but the successful development of these new therapeutic tools is conditioned by the understanding of the high adaptability of H. pylori to the gastric acidic environment and the complex pathogenic mechanism. Due to several advantages, including good antibacterial efficiency, possible targeted delivery, and long tissular persistence, silver nanoparticles (AgNPs) offer the opportunity of exploring new strategies to improve the H. pylori therapy. A new paradigm in the therapy of H. pylori gastric infections using AgNPs has the potential to overcome the current medical limitations imposed by the H. pylori drug resistance, which is reported for most of the current organic antibiotics employed in the classical therapies. This manuscript provides an extensive overview of the pathology of H. pylori-induced gastritis, gastric cancer, and extradigestive diseases and highlights the possible benefits and limitations of employing AgNPs in the therapeutic strategies against H. pylori infections.

Biochemical and Kinetic Characterization of the Glucose-6-Phosphate Dehydrogenase from Helicobacter pylori Strain 29CaP

Helicobacter pylori (H. pylori) has been proposed as the foremost risk factor for the development of gastric cancer. We found that H. pylori express the enzyme glucose-6-phosphate dehydrogenase (HpG6PD), which participates in glucose metabolism via the pentose phosphate pathway. Thus, we hypothesized that if the biochemical and physicochemical characteristics of HpG6PD contrast with the host G6PD (human G6PD, HsG6PD), HpG6PD becomes a potential target for novel drugs against H. pylori. In this work, we characterized the biochemical properties of the HpG6PD from the H.pylori strain 29CaP and expressed the active recombinant protein, to analyze its steady-state kinetics, thermostability, and biophysical aspects. In addition, we analyzed the HpG6PD in silico structural properties to compare them with those of the HsG6PD. The optimal pH for enzyme activity was 7.5, with a T_1/2 of 46.6 °C, at an optimum stability temperature of 37 °C. The apparent K_m values calculated for G6P and NADP⁺ were 75.0 and 12.8 µM, respectively. G6P does not protect HpG6PD from trypsin digestion, but NADP⁺ does protect the enzyme from trypsin and guanidine hydrochloride (Gdn-HCl). The biochemical characterization of HpG6PD contributes to knowledge regarding H. pylori metabolism and opens up the possibility of using this enzyme as a potential target for specific and efficient treatment against this pathogen; structural alignment indicates that the three-dimensional (3D) homodimer model of the G6PD protein from H. pylori is different from the 3D G6PD of Homo sapiens.

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.

Linolenic Acid-Metronidazole: a Compound Relieving Drug Resistance and Inhibiting Helicobacter pylori

Metronidazole (Met) is the first choice for treating Helicobacter pylori (Hp). However, Hp is easy to resistant, making Met unable to be widely used. How to overcome Hp’s Met resistance is still an issue. In this study, Met was used as the primary raw material with linolenic acid to prepare a novel compound-linolenic acid-metronidazole (Lla-Met). The MIC, minimum bactericidal concentration (MBC), colonization amount of Hp in gastric mucosa, etc., were evaluated, respectively. Lla-Met was successfully prepared by the detection of nuclear magnetic resonance, etc., and its MIC and MBC to Hp were 2~4 μg/mL, 8~16 μg/mL. Moreover, in vivo experiments, Lla-Met significantly reduced the colonization of drug-resistant Hp in gastric mucosa. In the toxicity test, Lla-Met inhibited rate to GES-1 and BGC823 cells were 15% at 128 μg/mL; the mice were administered 10 times treatment Lla-Met treatment (240 mg/kg), have no difference significant injuries were found in their stomach, liver, spleen, kidney, and weight. In addition, Hp G27 continued for 18 days in vitro with sub-Lla-Met concentration, G27 did not show drug resistance to Lla-Met; Lla-Met did not exert an effect on non-Hp species with 128 μg/mL; Compared with a neutral environment, when the acid concentration is 3.0, Lla-Met is not decomposed and has better stability. Conclusion: Lla-Met, a newly prepared compound, has relatively well antibacterial of Met-resistant and sensitive Hp, with a capability of overcoming the metronidazole resistance of Hp.

The Challenges of Eradicating Pediatric Helicobacter pylori Infection in the Era of Probiotics

Helicobacter pylori (H. pylori), the most common infection of childhood, results in life-threatening complications during adulthood if left untreated. Most of these complications are related to H. pylori-induced chronic inflammation. The dysbiosis caused by H. pylori is not limited to the gastric microenvironment, but it affects the entire gastrointestinal tract. Eradication of H. pylori has recently become a real challenge for clinicians due to both the persistent increase in antibiotic resistance worldwide and the wide spectrum of side effects associated with the eradication regimens resulting; therefore, there is an urgent need for more effective and less noxious treatment options. Thus, probiotics might be a promising choice in both adults and children with H. pylori infection since their role in improving the eradication rate of this infection has been proved in multiple studies. The positive effects of probiotics might be explained by their abilities to produce antimicrobial compounds and antioxidants, alter local gastric pH, and subsequently decrease H. pylori colonization and adherence to gastric epithelial cells. Nevertheless, if used alone probiotics do not considerably increase the eradication rate.

Targeting the Essential Transcription Factor HP1043 of Helicobacter pylori: A Drug Repositioning Study

Antibiotic-resistant bacterial pathogens are a very challenging problem nowadays. Helicobacter pylori is one of the most widespread and successful human pathogens since it colonizes half of the world population causing chronic and atrophic gastritis, peptic ulcer, mucosa-associated lymphoid tissue-lymphoma, and even gastric adenocarcinoma. Moreover, it displays resistance to numerous antibiotics. One of the H. pylori pivotal transcription factors, HP1043, plays a fundamental role in regulating essential cellular processes. Like other bacterial transcription factors, HP1043 does not display a eukaryote homolog. These characteristics make HP1043 a promising candidate to develop novel antibacterial strategies. Drug repositioning is a relatively recent strategy employed in drug development; testing approved drugs on new targets considerably reduces the time and cost of this process. The combined computational and in vitro approach further reduces the number of compounds to be tested in vivo. Our aim was to identify a subset of known drugs able to prevent HP1043 binding to DNA promoters. This result was reached through evaluation by molecular docking the binding capacity of about 14,350 molecules on the HP1043 dimer in both conformations, bound and unbound to the DNA. Employing an ad hoc pipeline including MMGBSA molecular dynamics, a selection of seven drugs was obtained. These were tested in vitro by electrophoretic mobility shift assay to evaluate the HP1043–DNA interaction. Among these, three returned promising results showing an appreciable reduction of the DNA-binding activity of HP1043. Overall, we applied a computational methodology coupled with experimental validation of the results to screen a large number of known drugs on one of the H. pylori essential transcription factors. This methodology allowed a rapid reduction of the number of drugs to be tested, and the drug repositioning approach considerably reduced the drug design costs. Identified drugs do not belong to the same pharmaceutical category and, by computational analysis, bound different cavities, but all display a reduction of HP1043 binding activity on the DNA.

Gossypol from Gossypium spp. Inhibits Helicobacter pylori Clinical Strains and Urease Enzyme Activity: Bioactivity and Safety Assessments

This study investigates the inhibitory activities of gossypol, a natural polyphenolic compound from Gossypium spp., against Helicobacter pylori (HP) clinical strains and a urease enzyme that plays a key role in the pathogenesis of HP. Gossypol was detected to exhibit a bacteriostatic action against all the HP strains tested with minimum inhibitory concentration (MIC) values ranging from 3.51 to 4.14 µg/mL. The activity of HP urease (HPU) was efficiently impeded by gossypol with a 50% inhibitory concentration (IC50) value of 3.3 µM using an Electrospray Ionization–Mass Spectrometry (ESI-MS)-based method. The in vitro cytotoxicity assay showed no significant cytotoxic properties of gossypol against human gastric epithelial cells. Additionally, molecular docking studies were performed to assess the binding mode and the molecular interactions of gossypol with HPU with a binding affinity value of −8.1 kcal/mol compared with an HPU–acetohydroxamic acid (a standard urease inhibitor) docking complex (–6.1 kcal/mol). The overall results reveal that gossypol might help fight against HP infection by two mechanisms of action: inhibition of the growth of HP and inhibition of urease.

Changes in Helicobacter pylori Treatment from Discovery to Nowadays: A High-Level Analysis of PubMed Publications

Background

Since the discovery of Helicobacter pylori (H. pylori) 40 years ago, treatment options have changed dramatically adjacent to new drugs development and the emergence of multi-drug resistance. In this study, we aimed to assess published literature on treatment regimens for H. pylori in the past four decades, with regards to specific drug resistance and geographic distribution.

Methods

We have queried PubMed for all available H. pylori-related entries published during 1987–2020. For each entry, we retrieved the title, abstract, and keywords. Two gastrointestinal specialists decided in consensus on a list of terms to classify entries. The terms specify types of treatment and different types of regimens. Annual trends of publications were plotted for different treatment types and sub-analyses.

Results

Overall, 47,170 H. pylori-related entries were published between 1987 and 2020. Medication treatment showed the highest number of total publications 6183/47,170 (13.1%), followed by antibiotics 5493/47,170 (11.6%), and probiotic which was substantially lower (0.7%). For treatment regimens type, triple therapy had the highest number of publications 2400/47,170 (5.1%) followed by sequential therapy 342/47,170 (0.7%), and bismuth quadruple therapy 115/47,170 (0.2%). Analysis by antibiotic resistance showed that clarithromycin treatment had the highest number of publications 3537/47,170 (7.5%). Since 2013, there is a steep upward slope (5.1±0.7 publications/year, p < 0.001) for publications originating from China.

Conclusion

Our findings reflect the changes of the commonly prescribed regimens along the years, following the occurrence and the rise of H. pylori antibiotic resistance. In recent years, there is a steep rise in publications in countries with policies of screening and eradication for gastric cancer prevention, which is currently not applied in Western countries. A text-mining analysis of H. pylori publications contributes to the understanding of treatment options and development trends worldwide.

In-vitro anti-Helicobacter pylori activity and preliminary mechanism of action of Canarium album Raeusch. fruit extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Canarium album Raeusch. belongs to the Burseraceae family. Its ripe fruits, known as Qing Guo (QG) in Traditional Chinese Medicine (TCM), are used to treat sore throat, cough, and fish or crab poisoning. QG was reported to have antibacterial activity, and it exerted excellent anti-Helicobacter pylori (H. pylori) activity in our screening of abundant TCM. However, few studies have reported its anti-H. pylori activity and mechanism.

AIM OF STUDY

The commonly used eradication therapies for H. pylori infection are antibiotic-based therapies. With the increasing antibiotic resistance of H. pylori, interest in finding alternative therapies has been aroused. This study investigated the phytochemistry profile, in vitro anti-H. pylori activity and possible anti-bacterial mechanism of QG extracts.

MATERIALS AND METHODS

QG extracts were obtained by heat reflux extraction, ultrasonic extraction or liquid-liquid extraction with different solvents. The quantitative and qualitative phytochemical analyses were performed by colorimetric determination, high-performance liquid chromatography (HPLC), and UPLC-electrospray ionization mass spectrometry (ESI-MS). In vitro anti- H. pylori activity was assessed by broth micro-dilution method. Mechanism of action studies included morphological observation using electron microscopy, urease inhibition assay and determination of expression of virulence genes by RT-qPCR.

RESULTS

All QG extracts especially ethyl acetate extract (QGEAE) were rich in phenolic components, with the minimum inhibitory concentrations (MICs) on H.pylori of 39-625 μg/ml and minimum bactericidal concentrations (MBCs) of 78-1250 μg/ml. Both aqueous extract (QGAE) and QGEAE could induce the morphological and structural changes of H. pylori, inhibit urease activity with IC₅₀ of 1093 μg/ml and 332.90 μg/ml, respectively, and down-regulate the virulence genes, such as vacA and cagA.

CONCLUSIONS

QG may exhibit in vitro anti-H. pylori activity by inhibiting growth, destroying the bacterial structure and down-regulating the expression of virulence factors. Moreover, QG is the homology of food and TCM, which can be considered as a safe and convenient agent against H. pylori infection.

The efficacy and safety of furazolidone-bismuth quadruple therapy for Helicobacter pylori eradication with or without probiotic supplementation

Aim

In this clinical trial we use furazolidone-bismuth quadruple therapy with or without probiotics for H.pylori eradication.

Background

Increasing rates of eradication failure in H.pylori infection mainly due to antibiotic resistance has led to search for alternative regimens such as using novel antibiotics and/or using probiotic supplementation as conjunctive to the standard eradication regimens.

Methods

This double blind clinical trial was performed in gastrointestinal clinic of Loghman Hakim University Hospital, Tehran, Iran. Patients with a positive pathology test for H.pylori were enrolled to the study and received a 14 day course of furazolidone 100 mg q.i.d, bismuth 240 mg b.i.d, amoxicillin 1000 mg b.i.d, pantoprazole 40 mg b.i.d plus either probiotic (Familact) b.i.d or placebo b.i.d. Adverse effects and adherence to therapy were evaluated at the end of the treatment course. Eradication was established by H.pylori fecal antigen test.

Results

A total of 200 patients entered the study and were randomly assigned to two groups of placebo and probiotic. There was no significant difference regarding age or gender between placebo and probiotic groups. Adherence to therapy was higher than 90% in total and not significantly different between placebo and probiotic groups. Total eradication rate was 80.5% (n=161). Eradication rate was 84% in probiotic group vs 77% in placebo group (P=0.2). Total rate of adverse effects was 30% in probiotic group vs 62% in placebo group. The most common adverse effects were abdominal pain (15% in probiotic group vs 28% in placebo group, P=0.03) followed by diarrhea (5% in probiotic group vs 12% in placebo group, P=0.1).

Conclusion

According to our results, adding probiotic to furazolidone-bismuth quadruple therapy did no increase the eradication rate significantly. However, adverse effects particularly abdominal pain was lower in the probiotic group when compared with placebo.

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.

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.

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.

Challenges and solutions in polymer drug delivery for bacterial biofilm treatment: A tissue-by-tissue account

To tackle the emerging antibiotic resistance crisis, novel antimicrobial approaches are urgently needed. Bacterial communities (biofilms) are a particular concern in this context. Biofilms are responsible for most human infections and are inherently less susceptible to antibiotic treatments. Biofilms have been linked with several challenging chronic diseases, including implant-associated osteomyelitis and chronic wounds. The specific local environments present in the infected tissues further contribute to the rise in antibiotic resistance by limiting the efficacy of systemic antibiotic therapies and reducing drug concentrations at the infection site, which can lead to reoccurring infections. To overcome the shortcomings of systemic drug delivery, encapsulation within polymeric carriers has been shown to enhance antimicrobial efficacy, permeation and retention at the infection site. In this Review, we present an overview of current strategies for antimicrobial encapsulation within polymeric carriers, comparing challenges and solutions on a tissue-by-tissue basis. We compare challenges and proposed drug delivery solutions from the perspective of the local environments for biofilms found in oral, wound, gastric, urinary tract, bone, pulmonary, vaginal, ocular and middle/inner ear tissues. We will also discuss future challenges and barriers to clinical translation for these therapeutics. The following Review demonstrates there is a significant imbalance between the research focus being placed on different tissue types, with some targets (oral and wound biofims) being extensively more studied than others (vaginal and otitis media biofilms and endocarditis). Furthermore, the importance of the local tissue environment when selecting target therapies is demonstrated, with some materials being optimal choices for certain sites of bacterial infection, while having limited applicability in others.

Revisiting Therapeutic Strategies for H. pylori Treatment in the Context of Antibiotic Resistance: Focus on Alternative and Complementary Therapies

The prevalence of Helicobacter pylori infection remains significant worldwide and it depends on many factors: gender, age, socio-economic status, geographic area, diet, and lifestyle. All successful infectious diseases treatments use antibiotic-susceptibility testing, but this strategy is not currently practical for H. pylori and the usual cure rates of H. pylori are lower than other bacterial infections. Actually, there is no treatment that ensures complete eradication of this pathogen. In the context of an alarming increase in resistance to antibiotics (especially to clarithromycin and metronidazole), alternative and complementary options and strategies are taken into consideration. As the success of antibacterial therapy depends not only on the susceptibility to given drugs, but also on the specific doses, formulations, use of adjuvants, treatment duration, and reinfection rates, this review discusses the current therapies for H. pylori treatment along with their advantages and limitations. As an alternative option, this work offers an extensively referenced approach on natural medicines against H. pylori, including the significance of nanotechnology in developing new strategies for treatment of H. pylori infection.

Enhanced Antibacterial Potential of Amoxicillin against Helicobacter pylori Mediated by Lactobionic Acid Coated Zn-MOFs

H. pylori (Helicobacter pylori) causes a common chronic infectious disease and infects around 4.4 billion people worldwide. H. pylori was classified as a member of the primary class of stomach cancer (stomach adenocarcinoma). Hence, this study was conducted to design a novel lactobionic acid (LBA)-coated Zn-MOFs to enhance bactericidal activity of Amoxicillin (AMX) against H. pylori. The synthesized Zn-MOFs were characterized by various techniques which included Dynamic Light Scattering (DLS), Fourier Transform Infrared (FT-IR) Spectroscopy, Powder X-ray diffraction, scanning electron microscope, and atomic force microscope. They were capable of encapsulating an increased amount of AMX and investigated for their efficacy to enhance the antibacterial potential of their loaded drug candidate. Interestingly, it was found that LBA-coated Zn-MOFs significantly reduced the IC₅₀, MIC, and MBIC values of AMX against H. pylori. Morphological investigation of treated bacterial cells further authenticated the above results as LBA-coated Zn-MOFs-treated cells underwent complete distortion compared with non-coated AMX loaded Zn-MOFs. Based on the results of the study, it can be suggested that LBA-coated Zn-MOFs may be an effective alternate candidate to provide new perspective for the treatment of H. pylori infections.

Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications

Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.

Rheumatic Heart Disease and Its Association with H. pylori Infection

Acute rheumatic fever (ARF) triggered by Group A streptococcus bacterium due to post-infectious and non-supportive pharyngeal infection. Depending on certain conditions, such as genetic predisposition to the disease, the prevalence of various cases of rheumatism and socioeconomic status in different regions, ARF can have different clinical manifestations. The disease typically manifested by one or more acute episodes, whereas 30-50% of all repeated ARF status can result in chronic rheumatic heart disease (RHD) with gradual and irreversible heart valve damage and also have been found to be correlated with a raised risk of myocardial infarction (MI), cardiovascular disease (CVD) and dyslipidemia. The RHD is the only long-term consequence of ARF and the most serious. The development to chronic RHD is determined by many factors, most notably the frequent episodes of rheumatic fever (RF). The RHD is known socially and economically as being the most frequent heart disease in vulnerable populations. H.pylori infection has been proposed to be involved RHD greater than that of the normal healthy people. H.pylori can be considered as one of the probable risk factor for RHD.It was concluded that patients with H. Pylori should be advised to follow up in cardiology clinics to avoid any complications.

Rescue Therapies for H. pylori Infection in Italy

Background/Aims: Curing Helicobacter pylori infection remains challenging for clinicians, as no proposed first-line therapy achieves bacterial eradication in all treated patients so that several patients need two or more consecutive treatments. Bacterial culture with antibiotics susceptibility testing is largely unachievable in Italy, and empiric second-line and rescue therapies are generally used. This study aimed to identify what eradication regimens perform better in Italy, following first-line therapy failure. Methods: We performed a literature search on PubMed for studies on standard therapy regimens used as second-line or rescue treatments performed in adult patients. Studies including modified drug combinations were not considered. Both intention-to-treat and per- protocol analyses were computed for each therapy subgroup. Results: Data from 35 studies with a total of 4830 patients were eventually considered. As a second-line therapy, Pylera® (90.6%) and a sequential regimen (89.8%) achieved eradication rates significantly higher than other therapies. For third-line therapy, a levofloxacin-based regimen and Pylera® achieved comparable eradication rates (88.2% vs. 84.7%; p = 0.2). Among therapies used as fourth (or more) attempts, Pylera® and a rifabutin-based therapy achieved 77.4% and 66.4% cure rates, respectively (p = 0.013). A therapy sequence based on the type of first-line therapy used was proposed. Conclusions: Data obtained through our review indicate that standard therapies for H. pylori eradication can be used when following an appropriate sequence, allowing clinicians to improve the cure rate without resorting to bacterial culture.

Molecular testing for H. pylori clarithromycin and quinolone resistance: a prospective Chinese study

In China, there is a high prevalence of antibiotic-resistant Helicobacter pylori infections in the population. The aim of the study was to assess a new ARMS-PCR test for detection of H. pylori clarithromycin resistance (CR) and quinolone resistance (QR) mutations and evaluate the spectrum of antibiotic resistance in patients from three Chinese provinces. Sanger sequencing and multiplex ARMS-PCR were used to detect H. pylori CR and QR bacteria in gastric biopsy samples. Among the 1,182 patients enrolled with gastritis, 643 (54.4%) were positive for H. pylori. Of these, 371 (57.7%) had antibiotic-resistant strains, comprising 236 (63.6%) with a single drug antibiotic-resistant strain and 135 (36.4%) with multiple drug-resistant strains. Following Sanger sequencing analysis of 23S rRNA and gyrA gene for mutations (antibiotic resistance markers), rates of CR, QR, and multidrug resistance (CR and QR) were 19.9, 12.0, and 25.8%, respectively. The 23S rRNA CR mutation A2143G (286, 96.9%) and the gyrA QR mutations C261A (85, 31.5%) and G271A (71, 26.3%) were common. Benchmarking against Sanger sequencing results, multiplex ARMS-PCR test had a high diagnostic sensitivity and specificity for detection of CR (96 and 93%), QR (95 and 92%) and multidrug resistance (95 and 95%). Based on our findings, the high incidence of single and multiple antibiotic resistance requires the routine checking of antibiotic resistance in all patients with suspected H. pylori infections. Multiplex ARMS-PCR is a simple and rapid test that can be now used for more efficient treatment of H. pylori infections and reduces the misuse of antibiotics.

Cytotoxin-Associated Gene A-Positive Helicobacter pylori Promotes Autophagy in Colon Cancer Cells by Inhibiting miR-125b-5p

Objectives

To investigate the effects of cytotoxin-associated gene A- (CagA-) positive Helicobacter pylori on proliferation, invasion, autophagy, and expression of miR-125b-5p in colon cancer cells.

Methods

Colon cancer cells were cocultured with H. pylori (CagA+) to analyze the effects of H. pylori on miR-125b-5p and autophagy. Colon cancer cells infected with H. pylori (CagA+) were mimicked by transfection of CagA plasmid. The effects of CagA on the proliferation, invasion, and autophagy of colon cancer cells were analyzed. Cell counting kit-8 (CCK-8), clone formation, and Transwell assays were used to detect cell viability, proliferation, and invasion ability, respectively. Proteins and miRNAs were detected by western blotting and qPCR, respectively.

Results

H. pylori (CagA+) inhibited expression of miR-125b-5p and promoted autophagy in colon cancer cells. MiR-125 b-5p was underexpressed in colon cancer cells after CagA overexpression. CagA promoted colon cancer cell proliferation, invasion, and autophagy. Overexpression of miR-125b-5p inhibited the proliferation, invasion, and autophagy of colon cancer cells and reversed the effects of CagA.

Conclusion

H. pylori (CagA+) infection may promote the development and invasion of colon cancer by inhibiting miR-125b-5p.

Efficacy of levofloxacin, omeprazole, nitazoxanide, and doxycycline (LOAD) regimen compared with standard triple therapy to eradicate Helicobacter pylori infection: a prospective randomized study from a tertiary hospital in India

AIM

In this study, the efficacy of 14-day triple therapy was compared with that of a novel ten-day LOAD regimen to eradicate Helicobacter pylori infection in India.

BACKGROUND

Helicobacter pylorus infection is widespread in India. Resistance to antibiotics commonly used against Helicobacter pylori is increasing rapidly, leading to traditional triple therapy's lower success. Therefore, a search for a new regimen is needed.

METHODS

In this randomized trial, patients with Helicobacter pylori infection were randomized to a group receiving LOAD therapy (levofloxacin 250 mg OD, omeprazole 40 mg BD, nitazoxanide 500 mg BD, and doxycycline 100 mg OD) for ten days or a group receiving standard triple therapy (pantoprazole 80 mg, amoxicillin 2000 mg, and clarithromycin 1000 mg daily) in divided doses for 14 days). Gastric biopsy/RUT was done 10-12 weeks after completing therapy to confirm Helicobacter pylori eradication.

RESULTS

Eradication rates were significantly greater with the LOAD regimen than with standard triple therapy on both intention-to-treat analysis (82.75% vs. 60.26%, p = 0.001; difference, 22.49% [95% CI, 8.5-18%] and per-protocol analysis (83.3% vs. 62.75%, p = 0.002; difference, 20.55% [95% CI, 7.1-22.5%]). Both treatment regimens were well tolerated.

CONCLUSION

Although the rate of eradication of H. pylori infection was significantly higher with the LOAD regimen than triple therapy, the efficacy was still suboptimal, possibly because of fluoroquinolone resistance or the short course of treatment.

A Mouse Model of Helicobacter pylori Infection

Infection with Helicobacter pylori (H. pylori) is of great distress because of its vital role in the pathogenesis of chronic gastritis, peptic ulcers, and in the multi-step carcinogenic process of gastric cancer. The increasing antibiotic resistance pattern of H. pylori worldwide has prompted the World Health Organization to put this organism in the priority pathogens list. To study the disease biology, evaluation of drugs, treatment outcome and to come up with probable vaccination strategies, competent animal models that reproduce the signature of human infection are essential. Initial reports about animal colonization with H. pylori have shown significant heterogeneity, to such an extent that Barry Marshall, Nobel laureate for the discovery of H. pylori , infected himself with the bacterium to show its involvement in acute gastric illness. A paradigm-shift discovery of the H. pylori mouse-adapted strain SS1 has opened the avenues of research regarding the organism and its pathogenicity. Although the mouse model of H. pylori infection is being utilized all over the world, there are certain issues that need awareness and specific information to achieve successful, consistent colonization with symptoms resembling human. This chapter details an established and reliable protocol for the development of a competent mouse model for H. pylori infection leading to various gastro-intestinal diseases.

Synergistic protective effects between docosahexaenoic acid and omeprazole on the gastrointestinal tract in the indomethacin-induced injury model

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used drugs due to their antipyretic, anti-inflammatory, and analgesic properties. However, NSAIDs can cause adverse reactions, mainly gastrointestinal damage. Omeprazole (OMP) exhibits gastroprotective activity, but its protection is limited at the intestinal level. For this reason, it is essential to utilize a combination of therapies that provide fewer adverse effects, such as the combined treatment of OMP and docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid with anti-inflammatory, analgesic, and gastroprotective activities. The objective of this study was to evaluate the pharmacological interaction between DHA and OMP in a murine model of indomethacin-induced gastrointestinal damage. The gastroprotective and enteroprotective effects of DHA (0.3-10 mg/kg, p.o.), OMP (1-30 mg/kg, p.o.), or the combination treatment of both compounds (3-56.23 mg/kg, p.o.) were evaluated in the indomethacin-induced gastrointestinal damage model (30 mg/kg, p.o.). Since DHA and OMP exhibited a protective effect in a dose-responsive fashion, the ED₃₀ for each individual compound was determined and a 1:1 combination of DHA and OMP was tested. Isobolographic analysis was used to determine any pharmacodynamic interactions. Since the effective experimental dose ED₃₀ (Zexp) of the combined treatment of DHA and OMP was lower than the theoretical additive dose (Zadd; p < .05) in both the stomach and small intestine their protective effects were considered synergistic. These results indicate that the synergistic protective effects from combined treatment of DHA and OMP could be ideal for mitigating damage generated by NSAIDs at the gastrointestinal level.

Determination of B- and T- cell epitopes for Helicobacter pylori cagPAI: An in silico approach

BACKGROUND/AIMS

Helicobacter pylori is classified as a gram-negative bacteria and can cause significant diseases, including gastric cancer, mucosa-associated lymphoid tumor, peptic ulcer, and chronic gastritis. Recent studies have shown that some autoimmune diseases are also associated with H. pylori. In the past decades, polymorphisms of certain genes of H. pylori, mechanisms and strains of H. pylori, and new therapeutic approaches have continued to be defined. Bioinformatic tools continue to be used in drug design and vaccine design. This study aimed to investigate the cag pathogenicity island (cagPAI) of H. pylori using an in silico approach, which could contribute to vaccine studies.

MATERIALS AND METHODS

The pathogenicity island of H. pylori was obtained from GenBank and analyzed with ClustalW software. Structures of cag Virb11 (Hp0525) and an inhibitory protein (Hp1451) were obtained, and codon optimization and secondary and tertiary structure prediction for the cagPAI of H. pylori were analyzed using Garnier-Osguthorpe-Rabson IV secondary structure prediction method and self-optimized prediction method with alignment software. The BcePred prediction server was used to distinguish linear B-cell epitopes, and prediction of T-cell was obtained with NetCTL and MHCPred.

RESULTS

According to the physicochemical parameters, the cagPAI of H. pylori was analyzed and found to be stable, and 2 B-cell epitopes of cagPAI of H. pylori and 2 T-cell epitopes of cagPAI were found in this study.

CONCLUSION

B- and T-cell epitopes that we have identified can induce both humoral and cellular immune responses. Thus, these epitopes have a potential for vaccine studies. Consequently, this in silico analysis should be combined with other pieces of evidence, including experimental data, to assign function.

Wheat Germ-Derived Peptides Exert Antiadhesive Activity against Helicobacter pylori: Insights into Structural Characteristics of Identified Peptides

Approximately 50-80% of the world population are infected with H. pylori, which is categorized as a class I carcinogen. Antiadhesive therapy is emerging as a promising alternative to antibiotics against bacterial infection. This study demonstrated that defatted wheat germ protein hydrolysates (DWGPH) effectively inhibited H. pylori adhesion to gastric epithelial cells. DWGPH prepared by pronase possessed the best activity where its inhibitory percentage at 10 mg/mL was 51.7 ± 6.8% and the minimum antiadhesive concentration was 0.31 mg/mL. The antiadhesive activity is attributable to peptides acting as receptor analogs in binding to H. pylori. Peptides with potential H. pylori-binding ability (n = 267) were identified, and their structural characteristics were comprehensively analyzed, including net charge, Boman index, instability index, aliphatic index, molecular weight, isoelectric point, hydrophobicity, and Hmoment (α-helix and β-sheet). This work provided an array of peptide sequences for further exploration as putative ligands of H. pylori adhesins and for elucidating molecular mechanisms.

Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases

Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.