Coccoid forms of Helicobacter pylori causing active gastritis

According to research conducted by an investigator at St. Luke’s Roosevelt Hospital Center in New York, the coccoid form of Helicobacter pylori, thought to be dormant, can cause active gastritis. The study was presented at ASCP, held in September in Chicago.

Helicobacter pylori exists in two different morphological forms, spiral bacillary and coccoid. The spiral form is considered to be the infective form and the coccoid form the dormant one. At ASCP, researchers reported a case of chronic active gastritis associated exclusively with coccoid forms.

 An 89-year-old man presented with dyspeptic symptoms. An endoscopic gastric antral mucosal biopsy was performed. The tissue was examined using hematoxylin-eosin stain, giemsa stain, and immunohistochemical analysis using anti-Helicobacterpylori antibody on paraffin-embedded tissue sections. The gastric antralmucosa showed moderate chronic active gastritis. There were numerous basophilicrounded coccoid forms adherent to the surface and crypt epithelial cells in adistribution similar to spiral bacillary forms of H. pylori. These coccoid forms stained positive for giemsa stain and Helicobacter pylori immunohistochemical stain.

According to the researchers, there were no spiral bacillary forms of the bacteria identified after extensive examination of the level sections and immunohistochemical stain. Helicobacter pylori typically causes antral predominant chronic active gastritis. The patient in question had symptomatic chronic active gastritis; the biopsy showed coccoid forms of the bacterium in absence of spiral bacillary forms.