ISOLATION AND DETECTION OF HELICOBACTER PYLORI FROM PATIENTS SUFFERING FROM PEPTIC ULCER USING BIOCHEMICAL TESTS AND MOLECULAR TECHNIQUES

Abstract

Helicobacter pylori is the causative agent of most cases of gastritis. There is no established gold standard for the diagnosis of H. pylori infection. A reliable diagnosis is crucial to confirm that eradication therapy has been successful. Eighty gastric biopsy and blood samples were obtained from fasting Jordanian patients with Esophago-Gastro-Doudenoscopy (EGD). Several diagnosis tests for H. pylori infections were used and compared including: Culture, microscopic examination, histopathology, Rapid Urease Test (RUT), serology, biochemical tests, antibiotic susceptibility test and molecular method. Forty two patients were considered H. pylori positive in both histopathology examination and RUT test. On the other hand, 57 patient were detected to have anti-IgA, IgG H. pylori antibody positive by ELISA test. Ten patients had equivocal results but not in both tests. A total of 19 biopsy samples were positive for H. pylori according to culture test. This result was confirmed by endoscopic examination, urease, catalase and oxidase. A high percentages of resistance to vancomycin, polymyxin B and amoxicillin was observed (100, 100 and 94.7%, respectively) with various degree of sensitivity to all of the first line of antibiotics. Molecular technique (PCR) was used to detect CagA gene which appeared positive in 14 patients. We conclude that the histopathology and RUT tests are reliable invasive diagnosis for H. pylori. However, culture test appear to be the most important (if the therapy failed) to detect antibiotic susceptibility to H. pylori strains.