A comparative proteomic approach using metabolic pathways for the identification of potential drug targets against Helicobacter pylori

Screening Marine Microbial Metabolites as Promising Inhibitors of Borrelia garinii: A Structural Docking Approach towards Developing Novel Lyme Disease Treatment

Lyme disease caused by the Borrelia species is a growing health concern in many parts of the world. Current treatments for the disease may have side effects, and there is also a need for new therapies that can selectively target the bacteria. Pathogens responsible for Lyme disease include B. burgdorferi, B. afzelii, and B. garinii. In this study, we employed structural docking-based screening to identify potential lead-like inhibitors against the bacterium. We first identified the core essential genome fraction of the bacterium, using 37 strains. Later, we screened a library of lead-like marine microbial metabolites (n = 4730) against the arginine deiminase (ADI) protein of Borrelia garinii. This protein plays a crucial role in the survival of the bacteria, and inhibiting it can kill the bacterium. The prioritized lead compounds demonstrating favorable binding energies and interactions with the active site of ADI were then evaluated for their drug-like and pharmacokinetic parameters to assess their suitability for development as drugs. Results from molecular dynamics simulation (100 ns) and other scoring parameters suggest that the compound CMNPD18759 (common name: aureobasidin; IUPAC name: 2-[(4R,6R)-4,6-dihydroxydecanoyl]oxypropan-2-yl (3S,5R)-3,5-dihydroxydecanoate) holds promise as a potential drug candidate for the treatment of Lyme disease, caused by B. garinii. However, further experimental studies are needed to validate the efficacy and safety of this compound in vivo.

Exploring the inhibitory potential of in silico-designed small peptides on Helicobacter pylori Hp0231 (DsbK), a periplasmic oxidoreductase involved in disulfide bond formation

Introduction: Helicobacter pylori is a bacterium that colonizes the gastric epithelium, which affects millions of people worldwide. H. pylori infection can lead to various gastrointestinal diseases, including gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. Conventional antibiotic therapies face challenges due to increasing antibiotic resistance and patient non-compliance, necessitating the exploration of alternative treatment approaches. In this study, we focused on Hp0231 (DsbK), an essential component of the H. pylori Dsb (disulfide bond) oxidative pathway, and investigated peptide-based inhibition as a potential therapeutic strategy. Methods: Three inhibitory peptides designed by computational modeling were evaluated for their effectiveness using a time-resolved fluorescence assay. We also examined the binding affinity between Hp0231 and the peptides using microscale thermophoresis. Results and discussion: Our findings demonstrate that in silico-designed synthetic peptides can effectively inhibit Hp0231-mediated peptide oxidation. Targeting Hp0231 oxidase activity could attenuate H. pylori virulence without compromising bacterial viability. Therefore, peptide-based inhibitors of Hp0231 could be candidates for the development of new targeted strategy, which does not influence the composition of the natural human microbiome, but deprive the bacterium of its pathogenic properties.

Comparison Between Real-time Ammonium and pH Measurement, Immunohistochemistry, and Histochemistry for the Diagnosis of Helicobacter pylori

BACKGROUND

Helicobacter pylori (HP) infection has been implicated in several malignant and nonmalignant conditions. The confirmatory diagnosis of HP requires an endoscopic biopsy, followed by a rapid urease test, culture, and/or histopathologic examination using hemotoxylin and eosin, histochemical stains, or immunohistochemistry against HP. EndoFaster is a novel device that can perform real-time ammonium and pH measurements in gastric juice, allowing a diagnosis of HP during gastroduodenal endoscopy.

GOAL

This study aimed to validate the accuracy of EndoFaster and to compare different histochemical and immunohistochemical techniques for the diagnosis of HP infection.

STUDY

Consecutive patients who underwent upper endoscopy at our center were prospectively enrolled. During the endoscopy procedure, gastric juice was aspirated to perform an automatic analysis by EndoFaster and gastric biopsies were taken. Histologic sections were reviewed to assess the histopathologic features. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the EndoFaster test, Diff-Quick (DQ), and immunohistochemistry against HP (anti-HP) using Warthin-Starry as the gold standard for HP detection.

RESULTS

Overall, 80 patients were enrolled. In 19 cases (23,75%), histology was normal. In the remaining cases, varying degrees of inflammation were found. The sensitivity, specificity, positive predictive value, and negative predictive value were 73.33%, 86.00%, 75.86%, and 84.31% for the EndoFaster test using 67 ppm/mL as the positive threshold; 73.33%, 100%, 100%, and 86.21% for DQ; and 79.31%, 88.00%, 79.31%, and 88.00% for anti-HP, respectively.

CONCLUSIONS

The EndoFaster test has good sensitivity and specificity for the diagnosis of HP during the gastroscopy procedure. DQ and anti-HP are excellent alternatives to Warthin-Starry for the detection of HP.

Helicobacter pylori treatment in the post-antibiotics era-searching for new drug targets

Abstract

Helicobacter pylori, a member of Epsilonproteobacteria, is a Gram-negative microaerophilic bacterium that colonizes gastric mucosa of about 50% of the human population. Although most infections caused by H. pylori are asymptomatic, the microorganism is strongly associated with serious diseases of the upper gastrointestinal tract such as chronic gastritis, peptic ulcer, duodenal ulcer, and gastric cancer, and it is classified as a group I carcinogen. The prevalence of H. pylori infections varies worldwide. The H. pylori genotype, host gene polymorphisms, and environmental factors determine the type of induced disease. Currently, the most common therapy to treat H. pylori is the first line clarithromycin–based triple therapy or a quadruple therapy replacing clarithromycin with new antibiotics. Despite the enormous recent effort to introduce new therapeutic regimens to combat this pathogen, treatment for H. pylori still fails in more than 20% of patients, mainly due to the increased prevalence of antibiotic resistant strains. In this review we present recent progress aimed at designing new anti-H. pylori strategies to combat this pathogen. Some novel therapeutic regimens will potentially be used as an extra constituent of antibiotic therapy, and others may replace current antibiotic treatments.

Key points

• Attempts to improve eradication rate of H. pylori infection.

• Searching for new drug targets in anti-Helicobacter therapies.