Can Helicobacter pylori invade human gastric mucosa?: an in vivo study using electron microscopy, immunohistochemical methods, and real-time polymerase chain reaction.

UNLABELLED

BACKGROUND-GOALS: We used transmission electron microscopy and immunohistochemistry (IHC) to investigate how Helicobacter pylori affects the gastric mucosa of humans.

STUDY

Gastric biopsy specimens were obtained from 15 patients with gastric discomfort. The samples were processed using both microscopic examinations and a real-time polymerase chain reaction to detect H. pylori DNA. IHC staining was performed with an avidin-biotin complex immunoperoxidase kit for paraffin-embedded tissue sections. Polyclonal rabbit anti-H. pylori was used as a primary antibody.

RESULTS

IHC-applied slides with brown-stained spiral bacteria on the luminal surface and in the intercellular spaces of the gastric epithelium; electron-dense spiral H. pylori of approximately 200 to 300 nm in diameter both in the gastric lumen and between the gastric epithelial cells; coccoid or ellipsoid H. pylori attached to the epithelial cells through egg-cup-like pedestals; coccoid H. pylori within the endocytotic vesicles in the apical cytoplasmic part of the epithelial cells, thus suggesting their internalization by phagocytosis; electron-dense spiral H. pylori within the membrane-bounded vacuoles of both the gastric epithelial cells, and the lamina propria; a prominent vacuolization of gastric epithelial cells invaded by H. pylori; and swollen and lytic gastric epithelial cells that suggest a mucosal erosion and may lead to peptic ulcer. All of these microscopic findings were not present in the H. pylori DNA-negative specimens that were used as the control group.

CONCLUSION

This is the first histomicrobiologic study to show gastric cells invaded by H. pylori in patients with H. pylori infection confirmed by real-time polymerase chain reaction.