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Updated: Jun 25, 2025

Gastric Mucosa Quantitative Polymerase Chain Reaction Analysis for Detecting Helicobacter pylori and Antibiotic Resistance
Published on: March 7, 2025
Exploring the Molecular Mechanisms of Macrolide Resistance in Laboratory Mutant Helicobacter pylori
Meltem Ayaş1,2, Sinem Oktem-Okullu3, Orhan Özcan4
1Department of Medical Laboratory Techniques, Vocational School of Health Services, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey.
Abstract:
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.
Insights
New mutations in Helicobacter pylori may cause clarithromycin resistance, a common cause of treatment failure. Researchers identified novel mutations in TauE/SafE and DUF874 proteins, suggesting new targets for antibiotic resistance research.
Area of Science:
- Microbiology
- Genetics
- Pharmacology
Background:
- Clarithromycin resistance in Helicobacter pylori is a major cause of treatment failure.
- While 23S rRNA mutations are common, other resistance mechanisms are not fully understood.
Purpose of the Study:
- To investigate novel macrolide resistance mechanisms in H. pylori.
- To identify new mutations associated with clarithromycin resistance.
Main Methods:
- Generation of resistant H. pylori strains through exposure to low clarithromycin concentrations.
- Whole-genome sequencing and Sanger sequencing to detect mutations.
- Agar dilution method for determining susceptibility.
Main Results:
- Both resistant strains possessed the known A2142G mutation in 23S rRNA.
- Mutant-1 strain showed candidate mutations in 23S rRNA and a novel mutation in the TauE/SafE protein gene.
- Mutant-2 strain exhibited a novel mutation in the DUF874 family protein gene.
Conclusions:
- Novel mutations in TauE/SafE and DUF874 family proteins may contribute to clarithromycin resistance or cross-resistance in H. pylori.
- These newly identified mutations represent potential targets for future research into antibiotic resistance mechanisms.
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