Application of PCR and ELISA for Investigation the Helicobacter pylori in Stool Specimens of Infected Patients

Abstract

Background: Infection with Helicobacter pylori is a global health issue, and non-invasive and accurate testing is a promising diagnostic method. Because H. pylori antibodies collapse quite gradually even after effective treatment. So, the tests for identifying the antibody of H. pylori are missing specificity and sensitivity. Instead, the tests of stool antigen for H. pylori are described as an alternative method because they have more reliability and simplicity. Aim: The study was aimed to assess the performance of enzyme-linked immunosorbent assays (ELISA), for the detection of H. pylori antigen in stool and compare it to molecular tests by using two housekeeping genes. Methods: Stool samples were collected from patients (85) who attended the Gastroenterology and Hepatology Teaching Center in Baghdad, Iraq, and underwent esophagogastroduodenoscopy (EGD) for biopsy in a period extended from November 2020 to July 2021. PCR and ELISA were used to Investigate H. pylori in stool specimens of infected patients. Results: The result revealed that 74/85 (87.88%) of specimens were positive by ELISA, whereas 49/85 (57.6%) were positive for the 16 SrRNA gene related to Helicobacter genus and 35/85 (41.1%) were positive for amiA gene related to H. pylori species, and that means the ELISA test is more accurate than PCR analysis for detection of H. pylori bacteria in stool specimen. Conclusion: Detection H. pylori Ag using the ELISA test was superior to the molecular test. Therefore, the ELISA test might replace other methods and could be used for the detection of active H. pylori infection before the inauguration of treatment between dyspeptic patients.