[Scanning electron microscopic study of Campylobacter pylori and associated gastroduodenal lesions]

The detection of Campylobacter pylori was carried out with scanning electron microscopy (SEM) on 4,590 biopsies taken from 1,714 adult patients (1,348 duodenal biopsies, 1,690 antral biopsies and 1,552 fundic biopsies). The mucus was removed and the fragments of mucosa were then fixed with glutaraldehyde, dehydrated, critical point-dried with CO2 or hexamethyldisilazane, mounted, coated with gold, and observed with SEM. Under SEM, C. pylori was characterized by its spiral-shape (long form 2.5 to 6 microns) or by its curved-shape (short form 1.5 microns) and by its relatively constant diameter (0.5 micron). C. pylori was present in 671 patients (40 p. 100) and was found mainly in the fundus and antrum, near the neck of the gastric glands and at the level of the intracellular spaces. It was never present on the surface of enterocytes but was found in the 26 duodenal biopsies in the gastric metaplasia areas and on the surface of adjacent muciparous cells. The main epithelial lesions associated with C. pylori were of an erosive or desquamative type. The high definition observed using SEM allowed C. pylori to be distinguished from other microorganisms observed on the surface of the gastroduodenal mucosa: bacilli and cocci contaminants, Candida albicans, Giardia lamblia, spirochetes and other Campylobacters. SEM is a specific and rapid technique (less than 2 hours) which determines the morphology, localisation of bacteria as well as the associated lesions of the mucous cells.