Evaluation of Mutations in rdxA and frxA genes of Helicobacter pylori in Paraffin-Embedded Gastric Biopsy Specimens from Iranian Gastric Cancer and Gastritis Patients

Evaluation of Mutations in rdxA and frxA genes of Helicobacter pylori in Paraffin-Embedded Gastric Biopsy Specimens from Iranian Gastric Cancer and Gastritis Patients
tahereh ebrahimi,¹ vahideh tarhriz,^2,* shirin eyvazi,³ parivar yazdani,⁴
1. Department of Nano-Biotechnology, Pasteur Institute of Iran, Tehran, Iran
2. Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
3. Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4. Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
Introduction: Helicobacter pylori (H. pylori) infection is considered as one of the main causes of gastric cancer. Treatment failure of the infection often occurs due to antibiotic resistance. Herein, we aimed to evaluate the mutations in rdxA and frxA genes of H. pylori which may be associated with metronidazole resistance, in paraffin-embedded gastric biopsies from patients with gastric adenocarcinoma and gastritis in Tabriz, the northwest of Iran
Methods: In the study, 80 paraffin-embedded tissue sections from 40 gastric cancer and 40 gastritis patients in the Imam Reza hospital, Tabriz, Iran were collected. The existence of ureC gene was verified by PCR method. PCR reaction and sequencing were used for the evaluation of mutations in rdxA and frxA genes.
Results: The results of ureC amplification showed that DNA of H. pylori was present in the 82.66% of the obtained DNA samples. About 53.22% of samples were resistant to the metronidazole. The mutations of rdxA gene were 66.66% missense, 30.30% frameshift and 3.03% non-sense. The mutations of frxA gene were 36.36% missense, 54.54% frameshift and non-sense 9.09%.
Conclusion: missense and frameshift mutations are frequent in rdxA and frxA genes. Screening for these mutations could help researchers to investigate the most effective anti-H. pylori antibiotics and to prevent antibiotic resistance.
Keywords: Gastric cancer, H. pylori, metronidazole resistance