Presence and density of Helicobacter pylori biofilms in human gastric mucosa in patients with peptic ulcer disease.

Our purpose was to use endoscopically directed biopsies and scanning electron microscopy to quantify Helicobacter pylori biofilm density on the surface of human gastric mucosa in urease-positive and -negative patients. Participating patients underwent flexible esophago-gastro-duodenoscopies coupled with gastric mucosal biopsies. Rapid urease testing was performed on all specimens to determine the presence of H. pylori, followed by scanning electron microscopy to identify the existence of biofilms. Samples were then analyzed using Carnoy Image Analysis Software to determine percent biofilm coverage of the total surface area. These data were compared to control specimens that were urease negative. Of the patients who tested urease positive for H. pylori, the average percent of total surface area covered by biofilms was 97.3%. Those testing negative had an average surface area coverage of only 1.64%. These differences were determined to be statistically significant at the 0.0001 level. This study demonstrates that compared with controls, urease-positive specimens have significant biofilm formation, whereas urease-negative specimens have little to none. This was reflected in the significantly increased biofilm surface density in urease positive specimens compared with urease-negative controls.