High incidence of antibiotic resistance amongst isolates of Helicobacter pylori collected in Nottingham, UK, between 2001 and 2018

Helicobacter pylori culture positivity and antimicrobial susceptibility profiles (Vancouver, Canada)

INTRODUCTION

Helicobacter pylori is associated with gastrointestinal diseases including gastritis and peptic ulcers. Despite its significance, there is a scarcity of antimicrobial susceptibility testing (AST) data available for this organism in North America.

OBJECTIVES

The aim of this study was to assess the AST profile and identify factors associated with H. pylori culture positivity in a cohort of patients with refractory H. pylori undergoing gastric biopsies.

METHODS

We retrospectively reviewed gastric biopsy specimens received for culture between July 2009 and February 2023. We analyzed specimen transport time, Gram smear results, direct urease test findings, culture positivity and AST profiles. Using gradient strip methodology and European Committee on Antimicrobial Susceptibility Testing breakpoints, AST was conducted for amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracycline.

RESULTS

Of 579 biopsy samples received for H. pylori culture, 228 (39.4%) tested positive. Samples transported within <1 h had significantly higher odds (1.81 times, P < 0.015) of being culture positive compared to those with longer transport times. Smear-positive samples had substantially higher odds (18.8 times, P < 0.001) of culture positivity compared to smear-negative. Urease-positive samples demonstrated notably higher odds (7.7 times, P < 0.001) of culture positivity compared to urease-negative samples. The collection of isolates from gastric biopsies showed susceptibility rates of 97.3% to amoxicillin, 99.1% to tetracycline, 50.4% to levofloxacin, 25.9% to metronidazole and 12.9% to clarithromycin.

CONCLUSIONS

Short sample transport time was associated with improved H. pylori recovery rates. In this cohort of refractory H. pylori cases, susceptibility rates were high for amoxicillin and tetracycline and low for clarithromycin, metronidazole and levofloxacin. Susceptibility rates remained stable over time.

Menadione reduces the expression of virulence- and colonization-associated genes in Helicobacter pylori

Novel treatment options are needed for the gastric pathogen Helicobacter pylori due to its increasing antibiotic resistance. The vitamin K analogue menadione has been extensively studied due to interest in its anti-bacterial and anti-cancer properties. Here, we investigated the effects of menadione on H. pylori growth, viability, antibiotic resistance, motility and gene expression using clinical isolates. The MIC of menadione was 313 µM for 11/13 isolates and 156 µM for 2/13 isolates. The minimum bactericidal concentrations were 1.25-2.5 mM, indicating that concentrations in the micromolar range were bacteriostatic rather than bactericidal. We were not able to experimentally evolve resistance to menadione in vitro. Sub-MIC menadione (16 µM for 24 h) did not significantly inhibit bacterial growth but significantly (P<0.05) changed the expression of 1291/1615 (79.9%) genes encoded by strain 322A. The expression of the virulence factor genes cagA and vacA was downregulated in the presence of sub-MIC menadione, while genes involved in stress responses were upregulated. Sub-MIC menadione significantly (P<0.0001) inhibited the motility of H. pylori, consistent with the predicted effects of the observed significant (P<0.05) downregulation of cheY, upregulation of rpoN and changes in the expression of flagellar assembly pathway genes seen in the transcriptomic analysis. Through in-depth interrogation of transcriptomic data, we concluded that sub-MIC menadione elicits a general stress response in H. pylori with survival in the stationary phase likely mediated by the upregulation of surE and rpoN. Sub-MIC menadione caused some modest increases in H. pylori susceptibility to antibiotics, but the effect was variable with strain and antibiotic type and did not reach statistical significance. Menadione (78 µM) was minimally cytotoxic to human gastric adenocarcinoma (AGS) cells after 4 h but caused a significant loss of cell viability after 24 h. Given its inhibitory effects on bacterial growth, motility and expression of virulence- and colonization-associated genes, menadione at low micromolar concentrations may have potential utility as a virulence-attenuating agent against H. pylori.

Helicobacter pylori: Routes of Infection, Antimicrobial Resistance, and Alternative Therapies as a Means to Develop Infection Control

Helicobacter pylori (H. pylori) is a Gram-negative, spiral-shaped bacterium that colonizes the gastric epithelium and is associated with a range of gastrointestinal disorders, exhibiting a global prevalence of approximately 50%. Despite the availability of treatment options, H. pylori frequently reemerges and demonstrates increasing antibiotic resistance, which diminishes the efficacy of conventional therapies. Consequently, it is imperative to explore non-antibiotic treatment alternatives to mitigate the inappropriate use of antibiotics. This review examines H. pylori infection, encompassing transmission pathways, treatment modalities, antibiotic resistance, and eradication strategies. Additionally, it discusses alternative therapeutic approaches such as probiotics, anti-biofilm agents, phytotherapy, phototherapy, phage therapy, lactoferrin therapy, and vaccine development. These strategies aim to reduce antimicrobial resistance and enhance treatment outcomes for H. pylori infections. While alternative therapies can maintain low bacterial levels, they do not achieve complete eradication of H. pylori. These therapies are designed to bolster the immune response, minimize side effects, and provide gastroprotective benefits, rendering them suitable for adjunctive use alongside conventional treatments. Probiotics may serve as adjunctive therapy for H. pylori; however, their effectiveness as a monotherapy is limited. Photodynamic and phage therapies exhibit potential in targeting H. pylori infections, including those caused by drug-resistant strains, without the use of antibiotics. The development of a reliable vaccine is also critical for the eradication of H. pylori. This review identifies candidate antigens such as VacA, CagA, and HspA, along with various vaccine formulations, including vector-based and subunit vaccines. Some vaccines have demonstrated efficacy in clinical trials, while others have shown robust immune protection in preclinical studies. Nevertheless, each of the aforementioned alternative therapies requires thorough preclinical and clinical evaluation to ascertain their efficacy, side effects, cost-effectiveness, and patient compliance.

Looking Back, Moving Forward: Challenges and Opportunities for Global Cervical Cancer Prevention and Control

Despite the introduction of Pap testing for screening to prevent cervical cancer in the mid-20th century, cervical cancer remains a common cause of cancer-related mortality and morbidity globally. This is primarily due to differences in access to screening and care between low-income and high-income resource settings, resulting in cervical cancer being one of the cancers with the greatest health disparity. The discovery of human papillomavirus (HPV) as the near-obligate viral cause of cervical cancer can revolutionize how it can be prevented: HPV vaccination against infection for prophylaxis and HPV testing-based screening for the detection and treatment of cervical pre-cancers for interception. As a result of this progress, the World Health Organization has championed the elimination of cervical cancer as a global health problem. However, unless research, investments, and actions are taken to ensure equitable global access to these highly effective preventive interventions, there is a real threat to exacerbating the current health inequities in cervical cancer. In this review, the progress to date and the challenges and opportunities for fulfilling the potential of HPV-targeted prevention for global cervical cancer control are discussed.

Helicobacter pylori infection in humans and phytotherapy, probiotics, and emerging therapeutic interventions: a review

The global prevalence of Helicobacter pylori (H. pylori) infection remains high, indicating a persistent presence of this pathogenic bacterium capable of infecting humans. This review summarizes the population demographics, transmission routes, as well as conventional and novel therapeutic approaches for H. pylori infection. The prevalence of H. pylori infection exceeds 30% in numerous countries worldwide and can be transmitted through interpersonal and zoonotic routes. Cytotoxin-related gene A (CagA) and vacuolar cytotoxin A (VacA) are the main virulence factors of H. pylori, contributing to its steep global infection rate. Preventative measures should be taken from people's living habits and dietary factors to reduce H. pylori infection. Phytotherapy, probiotics therapies and some emerging therapies have emerged as alternative treatments for H. pylori infection, addressing the issue of elevated antibiotic resistance rates. Plant extracts primarily target urease activity and adhesion activity to treat H. pylori, while probiotics prevent H. pylori infection through both immune and non-immune pathways. In the future, the primary research focus will be on combining multiple treatment methods to effectively eradicate H. pylori infection.