Comparison of four different methods for detection of Helicobacter pylori from gastric biopsies

Helicobacter pylori are commonly found colonizing the gastric mucosa of different populations. Its presence may be important in the pathogenesis of gastritis and peptic ulcer disease. The detection rates vary widely depending upon the diagnostic methods applied. In this study, multiple gastric biopsies were taken from the fundal and antral mucosa of 25 patients during endoscopy. In one patient, the procedure was repeated about two months after the initial biopsy. A total of 52 sets of specimens were obtained. One sample from each site was used to make imprint smear and tissue section. The other sample was used for microbiological culture and rapid urease test. An association between histological confirmed chronic gastritis (both active and inactive) and the morphological diagnosis of H. pylori by tissue sections was found in all of the 26 cases (52 specimens). There was an excellent concordance (96.2%) between the morphological diagnosis of H. pylori in the Gram-stained imprint smears and the tissue sections. There was a good concordance (86.5%) between the histology and the bacterial culture. Interestingly, a different species of gastric campylobacter-like organism with similar morphological appearance was also cultivated. The results of rapid urease test are unsatisfactory because urease was detected in less than 10% of culture-positive biopsies after 1 hour and 71.1% after 24 hours. In summary, culture and histology are complementary to each other. The combination of both is the "gold standard" for confirming the presence of H. pylori. As for rapid diagnosis, the Gram-stained imprint smears are shown to give satisfactory results.