DETECTION OF COCCOID HELICOBACTER-PYLORI - LIGHT-MICROSCOPIC IMMUNOGOLD-SILVER ENHANCING STAIN

Background. Helicobacter pylori (H. pylori) can be morphologically div ided into spiral and coccoid forms. Although many different staining p rocedures for light microscopy have been developed to detect H. pylori , there are no reports that the coccoid forms can be specially identif ied by a staining method. The ability to identify the coccoid form of H. pylori by light microscopy would be important for studies evaluatin g its possible role in gastric disease. We examined whether both the c occoid and the spiral forms could be stained using anti-H. pylori anti body. Methods. Specimens from the stomachs of dyspeptic patients with proven H. pylori infection and H. pylori from culture (1st and 4th day ) were stained with the light microscopic immunogold silver enhancing stain using the rabbit IgG specific for H. pylori. Cultured H. pylori was also stained with electron microscopic immunogold staining method using the same antibody. The number of coccoid forms was counted by sc anning electron microscopy. Results. Biopsies and H. pylori from 6 pat ients were studied. H. pylori from both biopsy material and culture ap peared as black organisms by light microscopic immunogold silver enhan cing stain. The coccoid forms constituted 0.4% and 98.3% on days 1 and 4 of culture, respectively (by scanning electron microscopy). The ant igen recognized by the anti-H. pylori antibody was located on the surf ace of the flagella, the cell wall, or in the cytoplasm by immunoelect ron microscopy. Conclusion. This study shows that both spiral and cocc oid forms of H. pylori can be detected by light microscopic immunogold silver enhancing stain using anti-H. pylori antibody. This simple sta in is to be proven useful for studies aimed at understanding whether t he coccoid form plays a role in disease.