Comparison of three diagnostic methods to confirm Helicobacter pylori infection

Abstract

Helicobacterpylori induces gastric inflammation in host and such gastritis increases the risk of gastric and duodenal ulceration as well as adenocarcinoma. Because peptic ulcer disease is the major cause of morbidity, accurate diagnosis of H. pylori infection is very important. Unfortunately, there is no gold standard among diagnostic tests for Helicobacter infections. If gastroscopy is performed, histopathology and urease test are the most often used. Still, culturing of this bacterium is essential for drug susceptibility testing and analysis of virulence factors. The aim of this study was to compare three diagnostic procedures--histopathology, urease test and culture, which are used to verify H. pylori infection. Three pairs of gastric mucosal biopsy specimens were collected from each of 28 dyspeptic patients undergoing endoscopy. Nineteen patients were not pretreated with antibiotics, while nine had received eradication therapy earlier. One pair of biopsy specimens was used for histopathologic examination, the second for urease test and the third was simultaneously cultured on nonselective and selective solid media. Isolate was identified as H. pylori on the basis of colony morphology, morphological properties and biochemical tests. In 14 out of 28 patients, H. pylori infection was confirmed on the basis of results of all diagnostic procedures. The concordance of these three methods was very good, because the results of histopathology, urease test and culture corresponded in 26 from 28 patients. The conclusion of our study is that culture, as the method with high degree of concordance with other two procedures and the only that can give information on drug susceptibility of Helicobacter, is recommended for diagnosis of Helicobacter pylori infection along with histopathology and urease test.