Helicobacter pylori detection and antimicrobial susceptibility testing

Association Between Biofilm Formation and Structure and Antibiotic Resistance in H. pylori

Background

Persistent infections caused by Helicobacter pylori (H. pylori), which are resistant to antibiotic treatment, pose a growing global public health concern. Biofilm formation is known to be associated with persistent infections due to its role in enhancing antimicrobial resistance and the tolerance of many pathogenic bacteria.

Objective

This study aims to evaluate the biofilm formation of clinical isolates of H. pylori and its impact on antibiotic eradication.

Methods

The thickness, morphology, and structure of biofilms derived from nine H. pylori strains were examined using confocal laser scanning microscopy, scanning electron microscopy, and transmission electron microscopy. Subsequently, the susceptibility of both planktonic and biofilm bacteria was assessed through the determination of minimum inhibitory concentration and minimum biofilm eradication concentration for amoxicillin, clarithromycin, levofloxacin, and tetracycline.

Results

The results revealed varying biofilm thicknesses and densities among the strains, characterised by the presence of numerous filaments intertwining and connecting bacterial cells. Additionally, several cases exhibited susceptibility based on MIC measurements but resistance according to MBEC measurements, with MBEC indicating a higher resistance rate. Pearson Correlation analysis demonstrated a positive correlation between biofilm thickness and MBEC results (0 < r < 1), notably significant for amoxicillin (r = 0.801, P = 0.009) and tetracycline (r = 0.696, P = 0.037).

Conclusion

Different strains of H. pylori exhibit variations in their capacity to release outer membrane vesicles (OMVs) and form biofilms. Biofilm formation can influence the effectiveness of amoxicillin and tetracycline in eradicating susceptible bacterial strains.

The second Irish Helicobacter pylori Working Group consensus for the diagnosis and treatment of Helicobacter pylori infection in adult patients in Ireland

BACKGROUND

There has been an increase in resistance to many of the antimicrobials used to treat Helicobacter pylori (H. pylori) nationally and internationally. Primary clarithromycin resistance and dual clarithromycin and metronidazole resistance are high in Ireland. These trends call for an evaluation of best-practice management strategies.

OBJECTIVE

The objective of this study was to revise the recommendations for the management of H. pylori infection in adult patients in the Irish healthcare setting.

METHODS

The Irish H. pylori working group (IHPWG) was established in 2016 and reconvened in 2023 to evaluate the most up-to-date literature on H. pylori diagnosis, eradication rates and antimicrobial resistance. The 'GRADE' approach was then used to rate the quality of available evidence and grade the resulting recommendations.

RESULTS

The Irish H. pylori working group agreed on 14 consensus statements. Key recommendations include (1) routine antimicrobial susceptibility testing to guide therapy is no longer recommended other than for clarithromycin susceptibility testing for first-line treatment (statements 6 and 9), (2) clarithromycin triple therapy should only be prescribed as first-line therapy in cases where clarithromycin susceptibility has been confirmed (statement 9), (3) bismuth quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) is the recommended first-line therapy if clarithromycin resistance is unknown or confirmed (statement 10), (4) bismuth quadruple therapy with a proton pump inhibitor, levofloxacin and amoxicillin is the recommended second-line treatment (statement 11) and (5) rifabutin amoxicillin triple therapy is the recommend rescue therapy (statement 12).

CONCLUSION

These recommendations are intended to provide the most relevant current best-practice guidelines for the management of H. pylori infection in adults in Ireland.

Exploring the Molecular Mechanisms of Macrolide Resistance in Laboratory Mutant Helicobacter pylori

Resistance to clarithromycin, a macrolide antibiotic used in the first-line treatment of Helicobacter pylori infection, is the most important cause of treatment failure. Although most cases of clarithromycin resistance in H. pylori are associated with point mutations in 23S ribosomal RNA (rRNA), the relationships of other mutations with resistance remain unclear. We examined possible new macrolide resistance mechanisms in resistant strains using next-generation sequencing. Two resistant strains were obtained from clarithromycin-susceptible H. pylori following exposure to low clarithromycin concentrations using the agar dilution method. Sanger sequencing and whole-genome sequencing were performed to detect resistance-related mutations. Both strains carried the A2142G mutation in 23S rRNA. Candidate mutations (T1495A, T1494A, T1490A, T1476A, and G1472T) for clarithromycin resistance were detected in the Mutant-1 strain. Furthermore, a novel mutation in the gene encoding for the sulfite exporter TauE/SafE family protein was considered to be linked to clarithromycin resistance or cross-resistance, being identified as a target for further investigations. In the Mutant-2 strain, a novel mutation in the gene that encodes DUF874 family protein that can be considered as relevant with antibiotic resistance was detected. These mutations were revealed in the H. pylori genome for the first time, emphasizing their potential as targets for advanced studies.

Description of a Case of Helicobacter pylori Infection with In Vitro Resistance to Tetracycline: An Exceptional Event with No Consequences?

Resistance in Helicobacter pylori to tetracycline is rare. We describe the case of an H. pylori strain with a high level of resistance to tetracycline (minimum inhibitory concentration = 12 mg/L). However, despite tetracycline resistance, bismuth quadritherapy was effective. Analysis of the patient's antibiotic treatment history over the previous 25 years revealed repeated 3-month courses of tetracycline for the treatment of acne, suggesting in vivo selection pressure responsible for the emergence of the triple mutation (AGA→TTC) in 16S rDNA associated with tetracycline resistance. This is a rare event but one worth monitoring, especially in view of the widespread use of bismuth quadritherapy for probabilistic treatment in countries where it is available.

Addressing Challenges in Standardizing Helicobacter pylori Treatment Protocols: Importance and Review

Helicobacter pylori, one of the top carcinogens, is associated with most cases of gastric cancer-related deaths worldwide. Over the past two decades, the rising rates of antibiotic resistance in the bacterium have reduced the efficacy of conventional antibiotic-based treatments. This underscores the urgency for continued research and novel treatment approaches. Establishing a worldwide accepted physician guideline for antibiotic prescription is crucial to combat antibiotic resistance and improve H. pylori infection management. Therefore, it is important to address the challenges that complicate the establishment of a universally accepted treatment protocol to prescribe an antibiotic regimen to eradicate H. pylori. The answers to the questions of why conventional standard triple therapy remains a first-line treatment choice despite its low efficacy, and how different factors affect therapy choice, are needed to identify these challenges. Hence, this review addresses concerns related to H. pylori treatment choice, role of antibiotic resistance and patient compliance in treatment outcomes, first-line vs. second-line therapy options, and methods for enhancing existing treatment methods. We also present a chart to aid antibiotic treatment prescription, which may support physician guidelines in this aspect. Eradication of H. pylori and patient adherence is paramount in overcoming antibiotic resistance in the bacterium, and our chart summarizes key considerations and suggests novel approaches to achieve this goal.

Testing for Helicobacter pylori in an era of antimicrobial resistance

Antimicrobial resistance in Helicobacter pylori has reached alarming levels and is compromising traditional empiric treatment of H. pylori. Antimicrobial susceptibility testing is routinely performed for infectious diseases when there is a risk of resistance and is now recommended to guide therapy for H. pylori. This mini-review overviews the current diagnostics for H. pylori with a focus on tests that enable susceptibility-guided treatment, including molecular tests performed directly on stool and endoscopically collected specimens.

Sequential versus Standard Triple Therapy for First-Line Helicobacter pylori Eradication: An Update

BACKGROUND

non-bismuth sequential therapy (SEQ) was suggested as a first-line anti-Helicobacter pylori treatment alternative to standard triple therapy (STT).

METHODS

We conducted a systematic review with a meta-analysis of randomized controlled trials (RCTs) comparing the efficacy of 10-day SEQ vs. STT (of at least 7 days) using bibliographical searches up to July 2021, including treatment-naïve adult or children. The intention-to-treat (ITT) eradication rate and the risk difference (RD) were calculated.

RESULTS

Overall, 69 RCTs were evaluated, including 19,657 patients (9486 in SEQ; 10,171 in STT). Overall, SEQ was significantly more effective than STT (82% vs. 75%; RD 0.08; p < 0.001). The results were highly heterogeneous (I2 = 68%), and 38 studies did not demonstrate differences between therapies. Subgroup analyses suggested that patients with clarithromycin resistance only and all geographical areas but South America could benefit more from SEQ. Both therapies have evolved over the years, showing similar results when STT lasted 14 days; however, a tendency toward lower SEQ efficacy was noted from 2010 onwards.

CONCLUSIONS

Prior to 2010, SEQ was significantly more effective than STT, notably when 7-day STT was prescribed. A tendency toward lower differences between SEQ and STT has been noted, especially when using 10-day STT. None of the therapies achieved an optimal efficacy and therefore cannot be recommended as a valid first-line H. pylori treatment.

A low-voltage alternant direct current electroporation chip for ultrafast releasing the genome DNA of Helicobacter pylori bacterium

Nucleic acid detection, as an important molecular diagnostic method, is widely used in bacterial identification, disease diagnosis. For detecting the nucleic acid of bacteria, the prerequisite is to release nucleic acids inside the bacteria. The common means to release nucleic acids is the chemical method, which involves complex processes, is time-consuming, and remains chemical inhibitors. Compared with chemical methods, electroporation as a physical method has the advantages of easy operation, short-time consumption, and chemical reagents free. However, the current works using electroporation often necessitates high-frequency or high-voltage conditions, entailing bulky power devices. Herein, we propose a low-voltage alternant direct current (LADC) electroporation chip and the corresponding miniature device for ultrafast releasing the genome DNA from Helicobacter pylori (H. pylori) for detection. We connected a micrometer-interdigital electrode in the chip with a 20 V portable battery to make the miniature device. Using this low-voltage device, our chip released genome DNA of H. pylori within only 5 ms, achieving a cell lysis rate of 99.5%. We further combined this chip with a colorimetric loop-mediated isothermal amplification assay to visually detect H. pylori within ~ 25 min at 10 CFU/μL. We detected 11 clinical samples using the chip, and the detection results were consistent with those of the clinical standard. The results indicate that the LADC electroporation chip is useful for ultrafast release of genome DNA from bacteria and is expected to promote the development of nucleic acid detection in POCT and other scenarios.

New strategies for Helicobacter pylori isolation and sequencing analysis for virulence genes contributing to its pathogenicity

BACKGROUND

Helicobacter pylori is a fastidious pathogen that is required a complicated medium for growth. Invading epithelial cells of the stomach. H. pylori virulence factors are classified by function, acidic resistivity, adhesion, chemotaxis and motility, molecular mimicry, immunological invasion and modulation, and toxins formation such as cytotoxin-associated genes A (cagA) and vacuolating cytotoxin A (vacA). This study aims to determine a simple and innovative technique to isolate H. pylori from gastric biopsies and assess pathogenicity by virulence factor gene detection.

METHODS

A total of 200 patients who were suspected of having H. pylori infection had two antral gastric biopsies undertaken. A rapid urease test (RUT) was used for one, and Brain Heart Infusion broth (BHI) was used to cultivate the other. The molecular study included diagnostics utilizing the 16sRNA housekeeping gene along with the identification of the virulence factors genes (cagA, cagT, and vacA) and sequencing, RESULT: Of the 200 antral gastric biopsies collected, 135 were positive rapid urease tests, and 17 H. pylori isolates were successfully obtained from 135 biopsies. The 16SrRNA as a housekeeping gene is confirmed, and about 53%, 70.5%, and 82.3% of the 17 isolates show carrying cagA, cagT, and vacA genes, respectively. All peptic ulcer isolates have the cagA gene, while Gastroesophageal Reflux Disease (GERD) and non-peptic ulcer disease (NPUD) isolates show the lack of the cagA gene. All bacteria, which were isolated from peptic ulcer, nodular gastritis, and gastritis patients, have a vacA gene.

CONCLUSION

The effective method for isolating H. pylori is centrifuging the transport broth after 24 h of incubation. The cagA toxin causes peptic ulcer while vacA toxin induces several histopathological changes in the stomach. Three virulence genes were present in all peptic ulcer-causing bacteria, while only one or none were present in the GERD and NPUD biopsy isolates.

Tailored therapy guided by genotypic resistance of clarithromycin and levofloxacin detected by polymerase chain reaction in the first-line treatment of Helicobacter pylori infection

OBJECTIVES

We aimed to explore the efficacy and safety of tailored therapy guided by genotypic resistance in the first-line treatment of Helicobacter pylori (H. pylori) infection in treatment-naive patients.

METHODS

Gastric mucosal specimens were taken during gastroscopy, and main mutations of clarithromycin- and levofloxacin-resistant genes were detected by polymerase chain reaction (PCR). Sensitive antibiotics were selected individually for treating H. pylori infection with tailored bismuth-containing quadruple therapy (BQT) consisting of esomeprazole 20 mg twice daily, bismuth potassium citrate 220 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily, or levofloxacin 500 mg once daily, or metronidazole 400 mg four times daily. Safety and patient compliance were assessed 1-3 days after eradication. Treatment outcome was evaluated by urea breath test 4-8 weeks after eradication.

RESULTS

One hundred and thirty-two treatment-naive patients with H. pylori infection were included. PCR results suggested resistance rates of 47.7% and 34.9% for clarithromycin and levofloxacin, respectively, and a dual resistance rate of 18.2%. Eradication rates of tailored BQT were 87.1% and 95.8% by intention-to-treat (ITT) analysis and per-protocol (PP) analysis, respectively. There was no statistically significant difference in the efficacy of 7-day clarithromycin-containing, 7-day levofloxacin-containing, and 14-day full-dose metronidazole-containing BQT (ITT analysis: P = 0.488; PP analysis: P = 0.833). The incidence of adverse events was 19.7%, and patient compliance was 97.7%.

CONCLUSION

Tailored BQT guided by genotypic resistance can achieve satisfactory efficacy, safety, and patient compliance in the first-line treatment of H. pylori infection.

Diagnosis of ''Helicobacter pylori infection of the gastric biopsy'' by rapid urease test, histopathology and Raman spectroscopy

This study aim to investigate the diagnostic potential of Raman spectroscopy in comparison with rapid urease test and histopathology in diagnosis of H. pylori infection. A comparative study was conducted at Pathology Laboratory and a total of 94 samples were collected from patients based on Rome IV criteria. Sensitivity, specificity and accuracy of histopathology, rapid urease test and for Raman spectroscopy were investigated. Rapid urease test showed 23 false negative results of H. pylori as compared to Raman spectroscopy and histopathology. We concluded that Raman spectroscopy showed sensitivity (94.5%), accuracy (94.0%) and specificity of (87.5%) in the diagnosis of H. pylori infection. However rapid urease test showed specificity of 92.5% while low sensitivity 75%, and 78% accuracy as compared to Raman spectroscopy and histopathology . This study illustrates the applicability of Raman spectroscopy as a potent innovative detection tool for the molecular detection of H. pylori infection in gastritis.

Co-administration of amoxicillin-loaded chitosan nanoparticles and inulin: A novel strategy for mitigating antibiotic resistance and preserving microbiota balance in Helicobacter pylori treatment

Helicobacter pylori (H. pylori) is a causative agent of various gastrointestinal diseases and eradication mainly relies on antibiotic treatment, with (AMX) being a key component. However, rising antibiotic resistance in H. pylori necessitates the use of antibiotics combination therapy, often disrupting gut microbiota equilibrium leading to further health complications. This study investigates a novel strategy utilizing AMX-loaded chitosan nanoparticles (AMX-CS NPs), co-administered with prebiotic inulin to counteract H. pylori infection while preserving microbiota health. Following microbroth dilution method, AMX displayed efficacy against H. pylori, with a MIC50 of 48.34 ± 3.3 ng/mL, albeit with a detrimental impact on Lactobacillus casei (L. casei). The co-administration of inulin (500 μg/mL) with AMX restored L. casei viability while retaining the lethal effect on H. pylori. Encapsulation of AMX in CS-NPs via ionic gelation method, resulted in particles of 157.8 ± 3.85 nm in size and an entrapment efficiency (EE) of 86.44 ± 2.19 %. Moreover, AMX-CS NPs showed a sustained drug release pattern over 72 h with no detectable toxicity on human dermal fibroblasts cell lines. Encapsulation of AMX into CS NPs also reduced its MIC50 against H. pylori, while its co-administration with inulin maintained L. casei viability. Interestingly, treatment with AMX-CS NPs also reduced the expression of the efflux pump gene hefA in H. pylori. This dual treatment strategy offers a promising approach for more selective antimicrobial treatment, minimizing disruption to healthy microbial communities while effectively addressing pathogenic threats.

Helicobacter pylori infection in pregnant women: Gastrointestinal symptoms and pregnancy- related disorders

Helicobacter pylori (H. Pylori) is a gram-negative, flagellated and spiral-shaped bacterial pathogen that impacts approximately 46% among pregnant women globally and has been associated with various maternal-fetal complications. Iron deficiency anemia, fetal growth restriction, cardiovascular diseases, and insufficient nutrient absorption can be observed in pregnant women, as well as miscarriages and pregnancy-specific hypertensive disease, such as pre-eclampsia. Thus, the evidence supports the influence of H. pylori infection on fetal implantation/placentation failure, and positive strains of the cytotoxin-associated gene A of H. Pylori were reported as the most prevalent in these conditions. However, current knowledge indicates a relationship between this infection and the occurrence of hyperemesis gravidarum, characterized by frequent nausea and vomiting. Regarding the diagnosis of this bacterial infection, non-invasive approaches such as stool antigen test, urea breath test, and serological tests are more accepted during pregnancy, as they are easy to carry out and cost-effective. Finally, the bacteria eradication therapy should consider the risks and benefits for the pregnant woman and her child, with pharmacological intervention depending on the clinical presentation.

Management of Helicobacter pylori treatment failures: A large population-based study (HP treatment failures trial)

BACKGROUND

Helicobacter pylori treatment failure remains a challenging problem. This study aimed to identify predictive factors for successful eradication in patients following treatment failures.

METHODS

This was a retrospective cohort study. This study included 1,050 dyspeptic patients diagnosed with H. pylori infection at tertiary care center in Thailand between March 2014 and October 2021. Patients' demographic data, endoscopic findings, H. pylori culture, antimicrobial susceptibility testing (AST), treatment regimens and outcomes were analysed.

RESULTS

Of 1,050 patients with H. pylori infections, 302 (28.7%) experienced treatment failure (mean age 58.4 years; 44.7% males). AST was performed in 192. Resistance was observed for metronidazole (43.2%), levofloxacin (33.9%), clarithromycin (24%), and amoxicillin (2.1%). There was no tetracycline resistance. Multidrug-resistance (MDR) was significantly more common following treatment failure (45.5% vs. 15.7%, p<0.001). Baseline characteristics were similar between treatment successes and failures. Eradication rates after first-line and second-line regimens were 71.2% and 54.5%, respectively. Medication nonadherence [OR 36.6 (95%CI 8.65-155.03, p<0.001)] and MDR [OR 4.49 (95%CI 2.29-8.81, p<0.001)] were associated with treatment failure. Over time, resistance increased for metronidazole, levofloxacin, and clarithromycin, while eradication rates with triple therapy declined. Tailored antibiotic therapy [OR 4.92 (95%CI 1.61-14.99, p = 0.005)] and a regimen including 4-times-daily dosing of amoxicillin (2 grams/day) [OR 3.05 (95%CI 1.10-8.41, p = 0.032)] were significantly associated with treatment success after first-line failure. Eradication rates when using tailored therapy and 4-times-daily dosing of amoxicillin (2 grams/day) were 91.1% and 89.4%, respectively. Performing AST before first-line therapy resulted in the highest cure rates. AST performed after multiple treatment failures was also associated with higher eradication rates compared with the group without AST (94.4% vs. 50%,p = 0.008).

CONCLUSIONS

AST either before or after treatment failure correlated with a higher proportion of successful eradication. Nonadherence and the MDR infections predicted treatment failure. Tailored therapy and 4-times-daily dosing of amoxicillin after treatment failure were likely to be successful.

Antibiotic Resistance in Helicobacter pylori Isolates from Northwestern and Central Romania Detected by Culture-Based and PCR-Based Methods

Little evidence has been published regarding the antimicrobial resistance patterns of Helicobacter pylori (H. pylori) strains in Northwestern and Central Romania. The aim of this study was to determine the antibiotic resistance pattern of H. pylori isolates from gastric biopsies collected from patients living in Romania using ETEST® and GenoType HelicoDR. Gastric biopsies were obtained from 148 adult patients, 87 women and 61 men, the majority (131 patients) from Northwestern and Central Romania. Sixty-nine H. pylori strains were detected by both culture and PCR; sixty-three biopsies were negative by both techniques; one biopsy was positive by culture but negative by PCR; and fifteen biopsies were negative by culture but positive by PCR. Primary resistance against clarithromycin, fluoroquinolones, and metronidazole was found in 16.7%, 11.1%, and 13.3% of strains, respectively. No primary resistance has been detected against amoxicillin, tetracycline, and rifampicin. Secondary resistance against clarithromycin, fluoroquinolones, metronidazole, amoxicillin, tetracycline, and rifampicin was found in 75.8%, 30.3%, 65.5%, 1.8%, 1.8%, and 7.3% of the strains, respectively. The most frequent clarithromycin-resistant genotype detected by GenoType HelicoDR was A2147G (62.3%). Concordances between ETEST® and PCR for clarithromycin and fluoroquinolones were 85.5% and 78.3%, respectively. Further investigation of H. pylori resistance should be conducted to ensure proper eradication schemes.

Computational insights into VacA toxin inhibition: harnessing FDA-approved antibiotics against Helicobacter pylori

Cancer is a condition in which a few of the body's cells grow beyond its control and spread to other outward regions. Globally, gastric cancer (GC) is third most common cause of cancer-related mortality and the fourth most common kind of cancer. Persistent infection of VacA-positive Helicobacter pylori (H. pylori) modulates cellular physiology and leads to GC. About ∼70% of H. pylori are positive for vacuolating cytotoxin-A (VacA), and it infects ∼80-90% of world populations. Herein, for first time, we repurposed FDA-approved gram-negative antibiotics, which are feasible alternatives to existing regimens and may be used in combinatorial treatment against VacA-positive H. pylori. Out of 110 FDA-approved antibiotics, we retrieved 92 structures, which were screened against the VacA protein. Moreover, we determined that the top eight hit antibiotics viz; cefpiramide, cefiderocol, eravacycline, doxycycline, ceftriaxone, enoxacin, tedizolid, and cefamandole show binding free energies of -9.1, -8.9, -8.1, -8.0, -7.9, -7.8, -7.8 and -7.8 Kcal/mol, respectively, with VacA protein. Finally, we performed 100 ns duplicate MD simulations on the top eight selected antibiotics showing strong VacA binding. Subsequently, five antibiotics, including cefiderocol, cefpiramide, doxycycline, enoxacin, and tedizolid show stable ligand protein distance and good binding affinity revealed by the MM-PBSA scheme. Among the five antibiotics cefiderocol act as the most potent inhibitor (-28.33 kcal/mol). Furthermore, we also identified the hotspot residue like Asn-506, Tyr-529, and Phe-483 which control the interaction. Concisely, we identified antibiotics that can be repurposed against VacA of H. pylori and explored their molecular mechanism of interaction with VacA.Communicated by Ramaswamy H. Sarma.

A Review of Helicobacter pylori Diagnostics in Africa : From the Bedside to the Laboratory

Helicobacter pylori (H. pylori) is endemic in Africa with a prevalence estimate of 79.1%. In addition, there is a significant community burden of dyspepsia in Africa, similar to other western countries. However, the majority of infected persons do not manifest the disease. In Africa, for instance, peptic ulcer disease is prevalent, whereas gastric cancer has reportedly low incidence. Therefore, it is important that testing is focused, targeting individuals most likely to benefit from treatment. In Africa, there are currently no guidelines for H. pylori testing and treatment. Empirical treatment is common due to variable access to diagnostics and health care. To assess the spectrum of H. pylori testing in Africa, we performed a literature search in PubMed over the past 10 years, 2013 to 2023. Histology was the most widely used modality in 16 out of 18 countries. Capacity for culture was shown in 11 studies, importantly across regions of Africa. H. pylori serology was demonstrated in 8 countries, although it has limited sensitivity in identifying active infection. H. pylori test-and-treat strategy has been shown to be cost-effective. Particularly in a region with high antibiotic resistance, adopting this strategy ensures that only confirmed positive patients are treated. Furthermore, test-of-cure ought to be mandatory to guide future therapies. Health authorities can leverage polymerase chain reaction facilities, left behind by the coronavirus disease 2019 pandemic, to make molecular susceptibility testing available in the near future. A systematic approach to testing incorporating indication for endoscopy and medication use is recommended.

Advances on diagnosis of Helicobacter pylori infections

The association of Helicobacter pylori to several gastric diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer, and its high prevalence worldwide, raised the necessity to use methods for a proper and fast diagnosis and monitoring the pathogen eradication. Available diagnostic methods can be classified as invasive or non-invasive, and the selection of the best relies on the clinical condition of the patient, as well as on the sensitivity, specificity, and accessibility of the diagnostic test. This review summarises all diagnostic methods currently available, including the invasive methods: endoscopy, histology, culture, and molecular methods, and the rapid urease test (RUT), as well as the non-invasive methods urea breath test (UBT), serological assays, biosensors, and microfluidic devices and the stool antigen test (SAT). Moreover, it lists the diagnostic advantages and limitations, as well as the main advances for each methodology. In the end, research on the development of new diagnostic methods, such as bacteriophage-based H. pylori diagnostic tools, is also discussed.

Practice guidelines for the management of Helicobacter pylori infection: The Saudi H. pylori Working Group recommendations

The eradication rates for Helicobacter pylori globally are decreasing with a dramatic increase in the prevalence of antibiotic resistant bacteria all over the world, including Saudi Arabia. There is no current consensus on the management of H. pylori in Saudi Arabia. The Saudi Gastroenterology Association developed these practice guidelines after reviewing the local and regional studies on the management of H. pylori. The aim was to establish recommendations to guide healthcare providers in managing H. pylori in Saudi Arabia. Experts in the areas of H. pylori management and microbiology were invited to write these guidelines. A literature search was performed, and all authors participated in writing and reviewing the guidelines. In addition, international guidelines and consensus reports were reviewed to bridge the gap in knowledge when local and regional data were unavailable. There is limited local data on treatment of H. pylori. The rate of clarithromycin and metronidazole resistance is high; therefore, standard triple therapy for 10-14 days is no longer recommended in the treatment of H. pylori unless antimicrobial susceptibility testing was performed. Based on the available data, bismuth quadruple therapy for 10-14 days is considered the best first-line and second-line therapy. Culture and antimicrobial susceptibility testing should be considered following two treatment failures. These recommendations are intended to provide the most relevant evidence-based guidelines for the management of H. pylori infection in Saudi Arabia. The working group recommends further studies to explore more therapeutic options to eradicate H. pylori.

Drug-Resistant Helicobacter pylori: Diagnosis and Evidence-Based Approach

Helicobacter pylori (H. pylori) is the most common chronic bacterial infection, affecting approximately half of the world's population. H. pylori is a Class I carcinogen according to the World Health Organization, and the International Agency for Research on Cancer (IARC) has linked it to 90% of stomach cancer cases worldwide. The overall pattern points to a yearly reduction in eradication rates of H. pylori with the likelihood of success further decreasing after each unsuccessful therapeutic effort. Antimicrobial resistance in Helicobacter pylori is a major public health concern and is a predominant cause attributed to eradication failure. As a result, determining H. pylori's antibiotic susceptibility prior to the administration of eradication regimens becomes increasingly critical. Detecting H. pylori and its antimicrobial resistance has traditionally been accomplished by time-consuming culture and phenotypic drug susceptibility testing. The resistance of H. pylori to different antibiotics is caused by various molecular mechanisms, and advances in sequencing technology have greatly facilitated the testing of antibiotic susceptibility to H. pylori. This review will summarize H. pylori antibiotic resistance patterns, mechanisms, and clinical implications. We will also review the pros and cons of current antibiotic susceptibility testing methods. Along with a comparison of tailored susceptibility-guided regimens and empirical therapy based on the latest evidence, an evidence-based approach to such situations will be explored.

Clarithromycin-induced acute liver injury in a patient with positive Helicobacter pylori: a case report and review of the literature

Introduction and importance

While 14-day triple therapy with clarithromycin is a common approach for eradicating Helicobacter pylori infection, it is essential to note that this treatment does not come without potential side effects.

Case presentation

We present the case of a 34-year-old male who presented to the emergency department with severe vomiting and abdominal pain. Subsequent evaluation revealed that the patient had developed drug-induced liver injury (DILI).

Clinical discussion

DILI can cause acute hepatocellular or cholestatic damage, and chronic injury can lead to hepatocellular, cholestatic, vascular, or neoplastic manifestations.

Conclusion

Clinicians should exercise caution and be alert to the potential hepatotoxic effects of medications, especially when initiating triple therapy for H. pylori infection.

Targeted delivery of a short antimicrobial peptide (CM11) against Helicobacter pylori gastric infection using concanavalin A-coated chitosan nanoparticles

Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections. The present study aims to develop a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of H. pylori infection. Accordingly, chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. Con-A was used for coating CS nanoparticles to target H. pylori. The CS NPs and ConA-CS NPs were characterized by FTIR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The MIC of CM11-loaded ConA-CS NPs against H. pylori SS1 strain was analyzed in vitro. In order to evaluate the treatment efficiency in vivo, a gastric infection model of H. pylori SS1 strain was established in mice and histopathological studies and IL-1β cytokine assay were performed. Based on the results, the size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm, respectively. The prepared CM11-loaded ConA-CS NPs exhibited antibacterial activity against H. pylori SS1 strain with a concentration of 32 µg/ml. The highest healing process was observed in synthesized CM11-loaded ConA-CS NPs treatments and a significant decrease in IL-1β was observed. Our findings highlight the potential of chitosan nanoparticles as a drug delivery vehicle in the treatment of gastric infection model of H. pylori SS1 strain.

Biofilm of Helicobacter pylori: Life Cycle, Features, and Treatment Options

Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori's chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, shifted morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori-targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm-targeted treatment strategies.

Antibiotic Resistance, Susceptibility Testing and Stewardship in Helicobacter pylori Infection

Despite the declining trend of Helicobacter pylori (H. pylori) prevalence around the globe, ongoing efforts are still needed to optimize current and future regimens in view of the increasing antibiotic resistance. The resistance of H. pylori to different antibiotics is caused by different molecular mechanisms, and advancements in sequencing technology have come a far way in broadening our understanding and in facilitating the testing of antibiotic susceptibility to H. pylori. In this literature review, we give an overview of the molecular mechanisms behind resistance, as well as discuss and compare different antibiotic susceptibility tests based on the latest research. We also discuss the principles of antibiotic stewardship and compare the performance of empirical therapies based on up-to-date resistance patterns and susceptibility-guided therapies in providing effective H. pylori treatment. Studies and clinical guidelines should ensure that the treatment being tested or recommended can reliably achieve a pre-agreed acceptable level of eradication rate and take into account the variations in antibiotic resistance across populations. Local, regional and international organizations must work together to establish routine antibiotic susceptibility surveillance programs and enforce antibiotic stewardship in the treatment of H. pylori, so that it can be managed in a sustainable and efficient manner.

Molecular testing-guided therapy versus susceptibility testing-guided therapy in first-line and third-line Helicobacter pylori eradication: two multicentre, open-label, randomised controlled, non-inferiority trials

BACKGROUND

Helicobacter pylori infection is an important causal factor of gastric cancer and peptic ulcer disease and is associated with immune thrombocytopenic purpura and functional dyspepsia. In H pylori strains, point mutations in the 23S rRNA and gyrA genes are associated with clarithromycin resistance and levofloxacin resistance, respectively. Whether the efficacy of molecular testing-guided therapy is non-inferior to that of susceptibility testing-guided therapy for H pylori eradication is unclear. Therefore, we aimed to compare the efficacy and safety of molecular testing-guided therapy and traditional culture-based susceptibility testing-guided therapy in first-line and third-line treatment of H pylori infection.

METHODS

We did two multicentre, open-label randomised trials in Taiwan. In trial 1 (done at seven hospitals), treatment-naive individuals infected with H pylori who were aged 20 years or older were eligible for study inclusion. In trial 2 (done at six hospitals), individuals aged 20 years or older who failed treatment after two or more eradication therapies for H pylori infection were eligible for enrolment. Eligible patients were randomly assigned (1:1) to receive either molecular testing-guided therapy or susceptibility testing-guided therapy. The randomisation sequence was generated by computer using permuted block randomisation with a block size of 4. All investigators were masked to the randomisation sequence. Clarithromycin and levofloxacin resistance were determined by agar dilution test for measuring minimum inhibitory concentrations in the susceptibility testing-guided therapy group, and by PCR and direct sequencing for detection of 23S rRNA and gyrA mutations in the molecular testing-guided therapy group. Study participants received clarithromycin sequential therapy, levofloxacin sequential therapy, or bismuth quadruple therapy according to the resistance status to clarithromycin and levofloxacin. The 13C-urease breath test was used to determine the status of H pylori infection at least 6 weeks after eradication therapy. The primary outcome was the eradication rate by intention-to-treat analysis. The frequency of adverse effects was analysed in patients with available data. The prespecified margins for non-inferiority were 5% for trial 1 and 10% for trial 2. The trials are ongoing for post-eradication follow-up and registered with ClinicalTrials.gov, NCT03556254 for trial 1, and NCT03555526 for trial 2.

FINDINGS

Between March 28, 2018, and April 23, 2021, 560 eligible treatment-naive patients with H pylori infection were recruited and randomly assigned to the molecular testing-guided therapy group or the susceptibility testing-guided therapy group in trial 1. Between Dec 28, 2017, and Oct 27, 2020, 320 eligible patients with refractory H pylori infection were recruited and randomly assigned to the molecular testing-guided therapy group or the susceptibility testing-guided therapy group in trial 2. 272 men and 288 women were recruited for trial 1, and 98 men and 222 women were recruited for trial 2. In first-line H pylori treatment, infection was eradicated in 241 (86%, 95% CI 82-90) of 280 patients in the molecular testing-guided therapy group and 243 (87%, 83-91) of 280 patients in the susceptibility testing-guided therapy group by intention-to-treat analysis (p=0·81). In third-line H pylori treatment, infection was eradicated in 141 (88%, 83-93) of 160 patients in the molecular testing-guided therapy group and 139 (87%, 82-92) of 160 patients in the susceptibility testing-guided therapy group by intention-to-treat analysis (p=0·74). The difference in the eradication rate between the molecular testing-guided therapy group and the susceptibility testing-guided therapy group was -0·7% (95% CI -6·4 to 5·0; non-inferiority p=0·071) in trial 1 and 1·3% (-6·0 to 8·5; non-inferiority p=0·0018 in trial 2 by intention-to-treat analysis. We found no difference in adverse effects across both treatment groups in trial 1 and trial 2.

INTERPRETATION

Molecular testing-guided therapy was similar to susceptibility testing-guided therapy in first-line therapy and non-inferior to susceptibility testing guided therapy in third-line treatment of H pylori infection, supporting the use of molecular testing-guided therapy for H pylori eradication.

FUNDING

Ministry of Science and Technology of Taiwan, and Centre of Precision Medicine of the Higher Education Sprout Project by the Ministry of Education of Taiwan.

Global Antimicrobial Resistance Gene Study of Helicobacter pylori: Comparison of Detection Tools, ARG and Efflux Pump Gene Analysis, Worldwide Epidemiological Distribution, and Information Related to the Antimicrobial-Resistant Phenotype

We conducted a global-scale study to identify H. pylori antimicrobial-resistant genes (ARG), address their global distribution, and understand their effect on the antimicrobial resistance (AMR) phenotypes of the clinical isolates. We identified ARG using several well-known tools against extensive bacterial ARG databases, then analyzed their correlation with clinical antibiogram data from dozens of patients across countries. This revealed that combining multiple tools and databases, followed by manual selection of ARG from the annotation results, produces more conclusive results than using a single tool or database alone. After curation, the results showed that H. pylori has 42 ARG against 11 different antibiotic classes (16 genes related to single antibiotic class resistance and 26 genes related to multidrug resistance). Further analysis revealed that H. pylori naturally harbors ARG in the core genome, called the 'Set of ARG commonly found in the Core Genome of H. pylori (ARG-CORE)', while ARG-ACC-the ARG in the accessory genome-are exclusive to particular strains. In addition, we detected 29 genes of potential efflux pump-related AMR that were mostly categorized as ARG-CORE. The ARG distribution appears to be almost similar either by geographical or H. pylori populations perspective; however, some ARG had a unique distribution since they tend to be found only in a particular region or population. Finally, we demonstrated that the presence of ARG may not directly correlate with the sensitive/resistance phenotype of clinical patient isolates but may influence the minimum inhibitory concentration phenotype.

Susceptibility patterns and virulence genotypes of Helicobacter pylori affecting eradication therapy outcomes among Egyptian patients with gastroduodenal diseases

BACKGROUND

Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis.

AIM

To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen.

METHODS

H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation.

RESULTS

The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%–70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175–0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: –0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026–0.537).

CONCLUSION

This study’s low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.

Novel Sensitive Electrochemical Immunosensor Development for the Selective Detection of HopQ H. pylori Bacteria Biomarker

Helicobacter pylori (H. pylori) is a highly contagious pathogenic bacterium that can cause gastrointestinal ulcers and may gradually lead to gastric cancer. H. pylori expresses the outer membrane HopQ protein at the earliest stages of infection. Therefore, HopQ is a highly reliable candidate as a biomarker for H. pylori detection in saliva samples. In this work, an H. pylori immunosensor is based on detecting HopQ as an H. pylori biomarker in saliva. The immunosensor was developed by surface modification of screen-printed carbon electrodes (SPCE) with MWCNT-COOH decorated with gold nanoparticles (AuNP) followed by HopQ capture antibody grafting on SPCE/MWCNT/AuNP surface using EDC/S-NHS chemistry. The sensor performance was investigated utilizing various methods, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). H. pylori detection performance in spiked saliva samples was evaluated by square wave voltammetry (SWV). The sensor is suitable for HopQ detection with excellent sensitivity and linearity in the 10 pg/mL-100 ng/mL range, with a 2.0 pg/mL limit of detection (LOD) and an 8.6 pg/mL limit of quantification (LOQ). The sensor was tested in saliva at 10 ng/mL, and recovery of 107.6% was obtained by SWV. From Hill's model, the dissociation constant Kd for HopQ/HopQ antibody interaction is estimated to be 4.60 × 10^-10 mg/mL. The fabricated platform shows high selectivity, good stability, reproducibility, and cost-effectiveness for H. pylori early detection due to the proper choice of biomarker, the nanocomposite material utilization to boost the SPCE electrical performance, and the intrinsic selectivity of the antibody-antigen approach. Additionally, we provide insight into possible future aspects that researchers are recommended to focus on.

Cost-Effectiveness of Vonoprazan-Based and Rifabutin-Based vs Other Regimens as First-Line Treatment of Helicobacter pylori Infection in the United States

INTRODUCTION

The economic and clinical implications of eradicating Helicobacter pylori ( H. pylori ) with vonoprazan-based and rifabutin-based regimens vs other existing prepackaged first-line treatment options in the United States are unknown. Therefore, we evaluated the cost-effectiveness of vonoprazan-based and rifabutin-based and other prepackaged regimens for the first-line treatment of H. pylori from the perspective of US healthcare payers.

METHODS

We used the state-transition Markov model to conduct a cost-effectiveness analysis of H. pylori eradication with clarithromycin triple, bismuth quadruple, vonoprazan dual, vonoprazan triple, and rifabutin triple regimens. In a cycle length of 2 months, the model estimated the expected costs (expressed in 2022 US$), expected quality-adjusted life-years (QALY), incremental cost-effectiveness ratios, and expected net monetary benefit over 20 years. In addition, we accounted for the present value of future costs and QALY by applying a 3% discounting rate.

RESULTS

In this study, rifabutin triple therapy had a lower expected cost but was more effective than clarithromycin triple, bismuth quadruple, and vonoprazan dual regimens; hence, it dominated them. Vonoprazan triple therapy had a higher expected cost (US$ 1,172 vs US$ 1,048) and expected QALY (14.262 vs 14.256) than rifabutin triple therapy, yielding an estimated incremental cost-effectiveness ratio of US$ 22,573/QALY. The study suggested that vonoprazan triple treatment had the highest expected net monetary benefit and was the most cost-effective at willingness-to-pay thresholds between US$50,000 and US$150,000 per QALY, followed by rifabutin triple therapy.

DISCUSSION

H. pylori infection eradication with vonoprazan triple therapy would provide the greatest net health and monetary benefit from the perspective of US healthcare payers.

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

BACKGROUND

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

RESULTS

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

CONCLUSION

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

Thin Layer Immunoassay: An Economical Approach to Diagnose Helicobacter pylori Infection in Gastroduodenal Ulcer Disease Patients of Pakistan, a Comparative Analysis

Helicobacter pylori is a causative agent of gastritis, gastroduodenal ulcers and gastric adenocarcinoma. The majority of H. pylori-associated patients live in underdeveloped areas, facing the problem of lack of proper diagnostic facility. Hence, a simple and economical assay is required to handle the majority of gastric patients. Serum samples from gastroduodenal ulcers and gastritis patients were screened for H. pylori infection by thin layer immunoassay. A polystyrene plate coated with H. pylori sonicate whole cell antigen (10 µg/mL). Two-fold diluted patient's serum was allowed to react at 37 °C, incubated at 60 °C for 1 min over a water bath and the water condensation pattern for the H. pylori antibody was recorded. ELISAs were used as reference assays to evaluate the efficacy of the developed thin layer immunoassay (TLI). Gastric patients' blood samples (62% male and 6% female) tested positive for H. pylori, while age-wise, 15-25-year-old males (36%) and 65-75-year-old females (50%) showed the highest number of H. pylori infections. TLI showed sensitivity (72-67%), specificity (100%), accuracy (94-69%) and κ value (0.493-0.357) in comparison with wELISA (Surface whole cell ELISA), sELISA (sonicate whole cell ELISA) and kELISA (commercial KIT ELISA). We conclude that thin layer immunoassay is a low cost, fast, simple and clinically reliable method for H. pylori diagnosis at initial stages in patients in under-developed countries.

Antibiotic Resistance and Therapeutic Efficacy of Helicobacter pylori Infection in Pediatric Patients-A Tertiary Center Experience

One of the most widespread bacterial infections worldwide, Helicobacter pylori is thought to affect almost half of the world's population. Due to rising antibiotic resistance, treatment should be tailored according to antibiotic susceptibility testing (AST). This study aims to evaluate Helicobacter pylori antibiotic resistance and its therapeutic efficacy in children. We conducted a prospective, single-center study, that evaluated 68 children referred for upper gastrointestinal endoscopy (UGE) following chronic dyspeptic syndrome. Each patient underwent multiple biopsies to perform bacterial cultures with AST and histopathological examinations for the diagnosis. Patients without antibiotic resistance or negative cultures received a 10-day sequential therapy, while the others had the antibiotic regimen tailored based on AST. Fifty-nine patients with a positive biopsy-based diagnosis (24 males) were finally included. Bacterial cultures with AST were positive for 13 patients (22.03%) and the antibiotic resistance for clarithromycin was 15.38%. Fifty-seven patients were administered sequential therapy with an eradication rate of 94.73%. Clarithromycin-resistant patients were successfully treated with 10-day triple therapy of esomeprazole, amoxicillin, and metronidazole. Although bacterial cultures had a low positivity rate, sequential therapy had a successful eradication rate. Further studies are necessary to better assess Helicobacter pylori antibiotic resistance to provide tailored treatment and identify children that need closer monitoring.

Multidrug resistance in Helicobacter pylori infection

Helicobacter pylori (Hp), a well-known human pathogen, causes one of the most common chronic bacterial infections and plays an important role in the emergence of chronic progressive gastric inflammation and a variety of gastrointestinal diseases. The prevalence of Hp infection varies worldwide and is indirectly proportional to socio-economic status, especially during childhood. The response to the eradication therapy significantly depends on the antibiotic resistance specific to each geographical region; thus, currently, given the increasing prevalence of antimicrobial resistance (especially to clarithromycin, metronidazole, and levofloxacin), successful treatment for Hp eradication has become a real challenge and a critical issue. The most incriminated factors associated with multidrug resistance (MDR) in Hp proved to be the overuse or the improper use of antibiotics, poor medication adherence, and bacterial-related factors including efflux pumps, mutations, and biofilms. Up to 30% of first-line therapy fails due to poor patient compliance, high gastric acidity, or high bacteremia levels. Hence, it is of great importance to consider new eradication regimens such as vonoprazan-containing triple therapies, quintuple therapies, high-dose dual therapies, and standard triple therapies with probiotics, requiring further studies and thorough assessment. Strain susceptibility testing is also necessary for an optimal approach.

Personalized Approach in Eradication of Helicobacter pylori Infection

The increase in antibiotic resistance to Helicobacter pylori (H. pylori) is associated with a decrease in the effectiveness of eradication therapy. Although some success has been achieved by adjusting therapeutic regimens according to local data on resistance to certain antibiotics, a new approach is needed to ensure a better therapeutic response. Tailored therapy, based on sensitivity tests to antibiotics, is increasingly proving to be a superior therapeutic option, even as a first-line therapy. Moreover, the recently published Maastricht VI guidelines emphasize utilizing a susceptibility-guided strategy in respect to antibiotic stewardship as the first choice for eradication therapy. In addition, polymerase chain reaction (PCR) technology is becoming a standard tool in the diagnosis of H. pylori infections through non-invasive testing, which further optimizes the eradication process. We provide a review regarding the current position of the individualized approach in eradication therapy and its future prospects. Based on novel understandings, the personalized approach is an effective strategy to increase the successful eradication of H. pylori infections.

Evaluation of a Molecular Mosprie Assay for Detection of Helicobacter pylori and Resistance to Clarithromycin and Levofloxacin

BACKGROUND

Helicobacter pylori eradication regimens should be guided by antimicrobial susceptibility testing. The objective of this study was to evaluate the molecular-based Mosprie assay for detecting H. pylori resistance to clarithromycin and levofloxacin using gastric biopsies.

METHODS

A total of 185 culture-positive frozen gastric biopsies were included for Mosprie assay and also for 23S rRNA and gyrA gene sequencing. The susceptibility results by the Mosprie assay were compared with the E-test results retrospectively retrieved. The discordant results were analyzed by sequencing of the 23S rRNA and gyrA genes.

RESULTS

Susceptibility concordance between the Mosprie assay and E-test for clarithromycin and levofloxacin was 97.30% (180/185) and 88.11% (163/185), respectively. The full agreement between clarithromycin genotypes by Mosprie assay and the 23S rRNA sequencing results was observed in the 5 samples with discordant Mosprie assay and E-test results. However, for levofloxacin, of the 16 discordant samples with resistant phenotype but a susceptible genotype by Mosprie assay, 6 were found to have levofloxacin resistance-related gyrA gene mutations.

CONCLUSIONS

The rapid and reliable Mosprie assay can be recommended for H. pylori susceptibility testing of clarithromycin and levofloxacin on gastric biopsies. Future technical improvements are needed in detecting levofloxacin resistance-associated gene mutations.

Reassessment of the Broth Microdilution Method for Susceptibility Testing of Helicobacter pylori

BACKGROUND

Helicobacter pylori infection is an infectious disease and thus the eradication treatment should be guided by susceptibility testing. This study aimed to assess the applicability of broth microdilution as a routine susceptibility testing method for H. pylori.

METHODS

Susceptibility profiles of clarithromycin (CLR) and levofloxacin (LEV) resistance in 76 clinical H. pylori isolates were simultaneously assessed using agar dilution and broth microdilution methods. The correlation between the minimum inhibitory concentrations (MICs) obtained by the 2 methods was assessed by means of linear regression analysis.

RESULTS

The correlation between the MICs determined by broth microdilution method and agar dilution method was good for both CLR (r = 0.966) and LEV (r = 0.959). The susceptibility agreement between the 2 methods was 100% for CLR and 96.1% for LEV. Using the broth microdilution method, the false resistance was found in 3.9% (3 of 76) strains for LEV susceptibility testing. No false susceptibility was found for either CLR or LEV, and no false resistance was found for susceptibility testing of CLR.

CONCLUSIONS

The broth microdilution method is suitable for routine susceptibility testing of clinical H. pylori isolates.

Correlation analysis of gastric mucosal lesions with Helicobacter pylori infection and its virulence genotype in Guiyang, Guizhou province, China

Background

Helicobacter Pylori (H. pylori) infection is the most important factor affecting clinical outcome in patients with gastric mucosal lesions. This study aimed to investigate H. pylori infection in patients with gastric mucosal lesions and their virulence genotype in Guiyang, China.

Methods

Pathological examinations of 1,364 biopsies from patients with upper gastrointestinal symptoms and H. pylori infection were analyzed according to different pathological types. The bacterial genome DNA was extracted from H. pylori strains isolated from gastric biopsies, and the cagA, vacA, and iceA virulence genes were detected and typed to analyze the correlation of their genotypes between different pathological lesions.

Results

The positive rate of H. pylori infection was approximately 19.9% (272/1,364), as determined by histopathological examination (HPE). It was more frequently detected in men than in women. A total of 85 H. pylori isolates were obtained from 280 clinical samples (positive rate 30.4%, 85/280). Of these 85 strains, cagA, vacA, and iceA genes were identified in 85.9%, 100%, and 83.5% of samples, respectively. Approximately 74.1% of strains were cagA East Asian type (cagA-ABD), and 11.8% of were cagA Western strains (cagA-AB, cagA-ABC), only present in patients with chronic non-atrophic gastritis. Gastric intraepithelial neoplasia and gastric cancer harbored both Asian strains. A total of 7 combinations of vacA genotypes were noted, among which s1c/m1b (30.6%) and s1c/m2 (41.2%) were the dominant genotypes. The predominant iceA genotype was iceA1 (64.7%).

Conclusions

We observed that the positive rate of H. pylori infection was related to the pathological type of patients' gastric mucosal lesions. Isolated H. pylori strains showed a unique genotype, mainly East Asian type cagA (ABD), vacA s1c/m2 genotype, and iceA1. These results provide an important reference for further studies of H. pylori in Guizhou province, China.

Diagnosis and Comparison of Three Invasive Detection Methods for Helicobacter pylori Infection

BACKGROUND

The purpose of this study was to compare different invasive methods for Helicobacter pylori (H. pylori) detection, namely PCR for H. pylori specific ureC gene, Rapid urease test (RUT), and histopathological examination by modified Giemsa staining.

METHODOLOGY

Endoscopic gastroduodenal biopsy materials were collected from dyspeptic patients who underwent endoscopic examination upon fulfilling the inclusion criteria. Three to four samples were collected from each patient after taking informed consent and proper clinical history. A rapid urease test (RUT) was done on spot with in-house RUT media from 1 specimen. One to two specimens were preserved in 10% formaldehyde for histopathology and PCR for ureC gene was done from 1 specimen. Collected biopsy specimens from gastric and duodenal mucosa of 142 patients were categorized as H. pylori-positive cases and H. pylori-negative cases based on the case definition used in the study upon positivity of 3 diagnostic tests.

RESULTS

Among 142 biopsy specimens, 34.5% were categorized as H. pylori-positive cases, 35.2% as H. pylori-negative cases, and finally 30.2% as doubtful or indeterminate cases. Rapid urease test was the most sensitive method, closely followed by ureC gene PCR and histopathology, with a sensitivity of 94.2%, 83.0%, and 76.5%, respectively. Whereas histology was the most specific, having 98.0% specificity followed by 83.0% in PCR. RUT was the least specific, with 55.5% specificity.

CONCLUSION

While histopathology could detect H. pylori infection with the highest specificity, for definitive diagnosis combination of any 2 methods should be used, if available.

Helicobacter pylori Antibiotic Resistance in Egypt: A Single-Center Study

Purpose

Helicobacter pylori (H. pylori) is the most common human bacterial infection worldwide, infecting approximately half of the world’s population. Although antibiotic use is indicated for H. pylori eradication, the recommended type of antibiotic varies from country to country according to the H. pylori resistance pattern; developing countries, such as Egypt, may have different patterns than developed countries. We evaluated the antibiotic resistance of H. pylori in Egypt.

Methods

This cross-sectional study included 134 adult patients with upper gastrointestinal (GI) complaints. Patients with a history of PPI during the last 2 weeks or antibiotics during the last 4 weeks before endoscopy were excluded. Upper GI endoscopies were performed and biopsies were collected for histopathology and H. pylori culture. Demographic, clinical, and endoscopic data were also collected. Antimicrobial susceptibility testing for H. pylori was performed for nine therapeutically relevant antibiotics using the Kirby–Bauer disc diffusion method.

Results

The H. pylori antibiotic resistance rates were as follows: moxifloxacin, 10%; doxycycline, 15%; levofloxacin, 20%; clarithromycin, 40%; azithromycin, 40%; erythromycin, 65%; rifampicin, 90%; amoxicillin, 95%; and metronidazole, 100%. Dual resistance rates were 40% for amoxicillin/clarithromycin, 40% for metronidazole/clarithromycin, and 95% for amoxicillin/metronidazole.

Conclusion

In Egyptian patients, H. pylori had >90% resistance to metronidazole and amoxicillin; modest resistance to erythromycin, azithromycin, and clarithromycin; and low resistance to moxifloxacin, and levofloxacin (≤20%). Dual resistance was high for amoxicillin/clarithromycin and amoxicillin/metronidazole, which prefers using quinolones rather than clarithromycin or metronidazole for first-line treatment of H. pylori in Egypt.

The influence of gastric atrophy on Helicobacter pylori antibiotics resistance in therapy-naïve patients

Background

Antibiotic susceptibility of Helicobacter pylori to antibiotics may vary among different niches of the stomach. The progression of chronic H. pylori gastritis to atrophy changes intragastric physiology that may influence selection of resistant strains.

Aim

To study the antibiotic resistance of H. pylori taking the severity of atrophic gastritis in antrum and corpus into account.

Methods

Helicobacter pylori-positive patients (n = 110, m = 32, mean age 52.6 ± 13.9 years) without prior H. pylori eradication undergoing upper gastrointestinal (GI) endoscopy for dyspeptic symptoms were included in a prospective study. Patients were stratified into three groups depending on the grade of atrophy: no atrophy (OLGA Stage 0), mild atrophy (OLGA Stage I–II) and moderate/severe atrophy (OLGA Stage III–IV). Two biopsies each from the antrum and the corpus and one from the angulus were taken and assessed according to the updated Sydney system. H. pylori strains were isolated from antrum and corpus biopsies and tested for antibiotic susceptibility (AST) for amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin by the agar dilution methods. A Chi-square test of independence with a 95% confidence interval was used to detect differences in the proportion of patients with susceptible and resistant H. pylori strains.

Results

Among 110 patients, primary clarithromycin resistance (R) was 30.0%, both in the antrum and corpus; metronidazole resistance accounted for 36.4 and 34.5% in the antrum and corpus; and levofloxacin was 19.1 and 22.7% in the antrum and corpus, respectively. Resistance rates to amoxicillin, tetracycline, and rifampicin were below 5%. Dual antibiotic resistance rate was 21.8%, and triple resistance rate was 9.1%. There was a significant difference in the resistance rate distribution in antrum (p < 0.0001) and corpus (p < 0.0001). With increasing severity of atrophy according to OLGA stages, there was a significant increase in clarithromycin-R and metronidazole-R.

Conclusion

In treatment-naïve patients, antibiotic resistance and heteroresistance were related to the severity of atrophy. The high clarithromycin resistance in atrophic gastritis suggests that H. pylori antibiotic susceptibility testing should always be performed in this condition before selecting the eradication regimen.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Antibiotic resistance of Helicobacter pylori isolated from patients in Nanjing, China: A cross-section study from 2018 to 2021

The increasing antibiotic resistance of Helicobacter pylori infection is a globally urging problem. To investigate the H. pylori resistance situation in Nanjing, China, we enrolled patients in Nanjing First Hospital from January 2018 to May 2021. H. pylori strains were isolated from patients who had at least one positive 13C-urea breath or rapid urease result. Subsequently, we performed antibiotic susceptibility tests on the isolated strains to clarithromycin, metronidazole, levofloxacin, amoxicillin, furazolidone and tetracycline. ARMS-PCR was conducted to determine H. pylori clarithromycin resistance gene mutation. Our results demonstrated that the primary resistance rates of metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone and tetracycline were 67.19% (1417/2109), 35.99% (759/2109), 24.23% (511/2109), 0.76% (16/2109), 0.28% (6/2109) and 0.09% (2/2109), respectively. The resistance rates of metronidazole, clarithromycin and levofloxacin elevated significantly after treatment and the three antibiotics composed the majority of multi-resistance patterns. However, the resistance rates of amoxicillin, furazolidone and tetracycline were still in low levels after treatment. ARMS-PCR showed a rather good consistency with antibiotic susceptibility test in detecting clarithromycin resistance, with a kappa value of 0.79. Overall, this study revealed the latest complex situation of antibiotic resistance of H. pylori infection in Nanjing and offered suggestions on clinical medication for curing H. pylori.

Evaluation of the Antibiotic Resistance Rate of Helicobacter pylori in Peptic Ulcer Patients in Tien Giang Central General Hospital, Tien Giang Province, Vietnam

BACKGROUND: Peptic ulcer (PU), trauma on the lining of the stomach and/or small intestine, is among the top five reasons for hospitalization in Tien Giang, a province in the South of Vietnam. Since Helicobacter pylori (HP) is one of the main causes of PU, its features, especially the antibiotic-resistant status, have critical significance in PU treatment. AIM: This study evaluates the HP infection prevalence, HP antibiotic resistance rate, and its associations with the patients’ sociodemographic characteristics. MATERIALS AND METHODS: A cross-sectional study was conducted on PU patients in Tien Giang province, Vietnam, from June 2020 to June 2021. The volunteers were tested for HP infection and antibiotic resistance using three methods, where appropriate, including Gram staining, CLO (urease) test, and bacterial culture method. RESULTS: Among 368 samples, 31.5% had infected with antibiotic-resistant HP. The resistance rates to five antibiotics commonly used in HP treatment, including metronidazole, clarithromycin, tetracycline, levofloxacin, and amoxicillin, were 96.6%, 94.8%, 70.7%, 61.2%, and 53.4%, respectively. The rates of tetracycline and clarithromycin resistance were related to alcohol consumption (t-test, p < 0.05). The HP treatment history was significantly associated with the levofloxacin resistance (t-test, p < 0.05). CONCLUSIONS: The emergence of antibiotic-resistant HP is a major public health concern in Tien Giang, Vietnam. This issue should be tackled at the national level to avoid the further spread of these multi-drug resistant HP strains.

Helicobacter pylori Antibiotic Resistance in the United States Between 2011 and 2021: A Systematic Review and Meta-Analysis

INTRODUCTION

Antimicrobial resistance among Helicobacter pylori strains has been rising globally, leading to declining eradication rates. We performed a systematic review and meta-analysis of the resistance patterns of H. pylori strains in the United States between 2011 and 2021.

METHODS

Ovid MEDLINE, Embase, CINAHL, and Cochrane CENTRAL databases were searched for manuscripts and conference abstracts published between 2011 and 2021 reporting H. pylori antibiotic resistance. A mixed-effects model estimated pooled rates of resistance to clarithromycin, amoxicillin, metronidazole, tetracycline, rifabutin, levofloxacin, or a combination of these, with 95% confidence intervals (CIs).

RESULTS

A total of 19 studies including 2,660 samples, met inclusion criteria. The pooled rate of resistance to metronidazole was 42.1% (95% CI 27.3%-58.6%), levofloxacin 37.6% (95% CI 26.3%-50.4%), clarithromycin 31.5% (95% CI 23.6%-40.6%), amoxicillin 2.6% (95% CI 1.4%-5.0%), tetracycline 0.87% (95% CI 0.2%-3.8%), rifabutin 0.17% (95% CI 0.00%-10.9%), and dual clarithromycin and metronidazole 11.7% (95% CI 0.1%-94.0%). Considerable data heterogeneity was evident for pooled resistance prevalence rates (I 2 &gt; 50%), with the exception of rifabutin resistance.

DISCUSSION

Metronidazole, levofloxacin, and clarithromycin resistance rates each exceed 30%; thus, choosing an empiric antibiotic regimen without knowledge of the likely pattern of antibiotic resistance is not appropriate. Resistance to tetracycline, rifabutin, and amoxicillin remains low. Given the scarcity of available data with considerable heterogeneity among studies, continued surveillance, ideally with a more systematic approach to data collection, is an increasingly important goal in H. pylori management.

The 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.

Automation of RIDA®GENE Helicobacter pylori PCR on the BD MAX™ System

PCR detection of Helicobacter pylori infection in gastric biopsies allows the detection of this bacterium and the mutations associated with macrolide resistance. The aim of this study was to evaluate the performance of RIDA®GENE H. pylori PCR (r-Biopharm) on a BD MAX™ System (Becton Dickinson). Two hundred ten gastric biopsies obtained were included. These biopsies were ground in nutrient broth. Two hundred microliters of this suspension was treated with proteinase K; 200 µL was transferred to a BD MAX™ sample tube then tested using RIDA®GENE H. pylori PCR reagents. In-house H. pylori PCR was used as a reference. The sensitivity of RIDA®GENE H. pylori PCR with BD MAX™ was 100%, the specificity was 99.08% (95% confidence interval (CI), 97.21-100%), the PPV was 99.02% (95% CI, 97.09-100%), and the NPV was 100% for the detection of H. pylori. The sensitivity was 97.14% (95% CI, 93.87-100%), the specificity was 100%, the PPV was 100%, and the NPV was 98.48% (95% CI, 96.08-100%) for categorization of macrolides resistance. The adaptation of RIDA®GENE H. pylori PCR on the BD MAX™ System is of considerable interest for microbiologists who seek to establish this assay in their laboratories.

Genotypic detection of metronidazole and clarithromycin resistance in dyspeptic patients with helicobacter pylori

In Egypt, antibiotic sensitivity analysis for Helicobacter pylori is not routinely performed. We aimed to identify the clarithromycin and metronidazole resistance directly from gastric biopsies for better guide treatment regimens. This cross-sectional descriptive study included 75 adult dyspeptic patients referred to the upper endoscopy unit in Suez Canal University Hospital, Ismailia, Egypt. Gastric biopsies were taken for rapid urease test (RUT) and cultured on brucella agar with antibiotic supplements. Genomic DNA was extracted directly from the specimen, and PCR was performed for direct detection of H. pylori. Also, to explore clarithromycin and metronidazole resistance, mutations in the 23S rRNA gene and the rdxA gene were investigated. We found that 60 samples were positive to RUT (80%), and only 4 samples were positive by culture. UreC gene was detected in 45 specimens. Meanwhile, 26 isolates were contained mutations at positions 2142 and 2143. Amplification of the metronidazole rdx gene was performed by conventional PCR. Out of 45 isolates, DNA sequence analysis of PCR product showed the wild type (ACA) in 9 isolates, while the mutant type (ATA) was detected in 28 isolates. We found a significant proportion of clarithromycin and metronidazole resistance among H. pylori infected patients in our region.

Association between Helicobacter pylori antibodies determined by multiplex serology and gastric cancer risk: A meta-analysis

BACKGROUND AND AIMS

Previous studies have reported the association between limited number of Helicobacter pylori (H. pylori) antigens and gastric cancer (GC) risk. The present study evaluated the association between serum antibodies against 15 different H. pylori proteins measured by using multiplex serology assay and GC risk.

METHODS

We searched PubMed databases, Embase, Web of Science, and Cochrane Library for relevant articles. A meta-analysis was used to pool studies and to estimate odds ratios (ORs) with 95% confidence intervals (95%CIs) of different H. pylori antigens associated with GC risk. Heterogeneity was investigated using Cochran's Q test and I-squared statistic.

RESULTS

Nine studies were identified, with a total of 3209 GC cases and 6964 controls. Five H. pylori virulence factors were significantly associated with non-cardia GC risk at p-value <0.0033 including: CagA (OR = 3.22, 95%CI: 2.10-4.94), HP0305 (OR = 1.72, 95%CI: 1.32-2.25), HyuA (OR = 1.42, 95%CI: 1.13-1.79), Omp (OR = 1.83, 95%CI: 1.30-2.58), and VacA (OR = 2.05, 95%CI: 1.67-2.52). However, none of the 15 antigens was associated with cardia GC risk. In subgroup analysis by ethnicity, we identified 7 antigens associated with the risk of non-cardia GC among East Asian while only two antigens were identified in European population. Nevertheless, CagA and GroEL showed a stronger association in Caucasian (CagA OR = 5.83, 95%CI: 3.31-10.26; GroEL OR = 3.66, 95%CI: 1.58-8.50) compared with East Asian (CagA OR = 2.20, 95% CI: 1.85-2.61; GroEL OR = 1.47, 95%CI: 1.29-1.68).

CONCLUSIONS

This study determined that H. pylori infection increases the risk of non-cardia GC with differential effects by its virulence factors and with different patterns among East Asian and European populations. These results advance the understanding of the effect of H. pylori on GC.