Identification of Helicobacter pylori biofilms in human gastric mucosa

Abstract

The purpose of this study was to use endoscopically directed biopsies and scanning electron microscopy (SEM) to document the existence of Helicobacter pylori biofilms in human gastric mucosa. Patients underwent flexible esophagogastroduodenoscopies with three gastric mucosal biopsies. Rapid urease testing was performed to determine the presence or absence of H pylori. Urease-positive and urease-negative control specimens were imaged with SEM to obtain detailed images of gastric mucosa for the identification of biofilm colonies. Samples were obtained from patients who underwent esophagogastroduodenoscopies. Eleven were found to be H pylori positive and nine were H pylori negative. These were imaged at 500x and 1000x with electron microscopy. Dense, mature biofilms were present and attached to the cell surface of H pylori-positive specimens and were absent in urease-negative controls. Photomicrographs were obtained. Biofilms are complex microbiological ecosystems where sessile bacteria surround themselves in a protective matrix. This lifestyle affords protection, allows for growth in hostile environments, and alters host physiology. Many have hypothesized that H pylori infections resulting in gastric ulcers may be a manifestation of biofilms. Our investigation is the first to photographically document the existence of H pylori biofilms on human gastric mucosa. This elucidation of the ecology and pathophysiology of the mucosa of the organism is important to our understanding of a potential mechanism of this organism's resistance to current therapy and how to better eradicate it in the future.