Isolation of Helicobacter pylori from Biopsy Samples of Patients with Gastritis

Abstract

Over 50% of the world's population is infected with Helicobacter pylori. Initial reports from all over the world indicate that ~ 95% of duodenal ulcers and 85% of gastric ulcers occur in the presence of H. pylori infection. Chronic infection with this pathogen is associated with the development of peptic ulcers and is linked to an increased risk of gastric cancer. The role of H. pylori in gastric cancer was first announced by the International Agency for Research on Cancer (IARC), when they labeled H. pylori a class I carcinogen. The present study was conducted to isolate H. pylori from tissue biopsies. Samples were collected from the stomach antrum or corpus during the period March 2017 to January 2018. Biopsy samples were confirmed by rapid urease test (RUT). The results showed that 83 samples were positive for H. pylori. Biopsies (n = 83) collected during endoscopic examinations were cultivated for 3-7 days using a growth medium selective for H. pylori. About 70 bacterial cultures from the biopsy samples were isolated as positive cultures. All isolates were stained with Gram-negative bacteria. The bacterial culture isolates also showed positive results using oxidase, catalase, and urease tests. H. pylori are fastidious microorganisms. The culture is 100% specific, but sensitivity is low. Several factors are involved in successful H. pylori cultivation, including method, time, procedure for tissue processing, composition of culture media, contamination of biopsy forceps, and the requirement of specific microbiological expertise. However, this method is currently the only way to obtain pure cultures for selecting antibiotics and biological compounds to reduce drug resistance. Further investigations should focus on developing biological compounds for the treatment of H. pylori infection.