Considering the clarithromycin resistance prevalence among Helicobacter pylori strains isolated from patients with Gastric complication

Objective: Helicobacter pylori is a major cause of gastric cancer. This study aimed to determine the frequency of clarithromycin resistance and its association with point mutations in the 23S rRNA gene. Methods: This study was conducted on 100 patients with gastric disorders who were referred to Valiasr Hospital in 2022. Two biopsy samples were obtained from each patient for pathological and microbiological examinations. Antimicrobial susceptibility testing was performed using the agar dilution method, and polymerase chain reaction (PCR) was used for molecular analysis.Results: Among the patients, 53% (53/100) were diagnosed as H. pylori-positive. Pathological findings indicated that 54.7% (29/53) of the H. pylori-positive patients had chronic gastritis, 37.7% (20/53) had severe active gastritis, and 7.5% (4/53) had intestinal metaplasia. Clarithromycin resistance was detected in 13.2% (7/53) of the patients. The MIC50 and MIC90 values were determined to be 0.125 mg/L and 2 mg/L, respectively. PCR results revealed that the A2142G point mutation in the 23S rRNA gene was present in all clarithromycin-resistant strains. Conclusions: Our findings indicate that the presence of the A2142G point mutation in the 23S rRNA gene may be associated with clarithromycin resistance in H. pylori strains. These results underscore the importance of routine screening for resistance genotypes to guide effective treatment strategies.