%0 Journal Article %T Cytotoxic isolates of Helicobacter pylori from Peptic Ulcer Diseases decrease K+-dependent ATPase Activity in HeLa cells %A Awasthi Shanjana %A Ayyagari Archana %J BMC Gastroenterology %D 2003 %I BioMed Central %R 10.1186/1471-230x-3-31 %X The patients were retrospectively grouped on the basis of endoscopic and histopathological observation as having gastritis or peptic ulcer. The HeLa cells were incubated with the broth culture filtrates (BCFs) of H. pylori isolates from patients of both groups and observed for the cytopathic effects: morphological changes and viability. In addition, the K+-dependent ATPase activity was measured in HeLa cells extracts.The cytotoxin production was observed in 3/7 (gastritis) and 4/4 (peptic ulcer) H. pylori isolates. The BCFs of cytotoxin producing H. pylori strains reduced the ATPase activity of HeLa cells to 40% of that measured with non-cytotoxin producing H. pylori strains (1.33 ¦̀mole Pi/mg protein and 3.36 ¦̀mole Pi/mg protein, respectively, p < 0.05). The decreased activity of ATPase enzyme or the release of cytotoxin also correlated with the increased pathogenicity indices of the patients.Our results suggest that the isolation of cytotoxic H. pylori is more common in severe form of acid peptic diseases (peptic ulcer) than in gastritis patients from India. Also the cytotoxin released by H. pylori impairs the ion-transporting ATPase and is a measure of cytotoxicity.Helicobacter pylori is a spiral Gram negative, microaerophilic bacterial parasite that inhabitates gastric epithelium [1]. The long-term H. pylori infection has been found associated with gastritis, gastric and duodenal ulcer, B-cell lymphoma and adenocarcinoma of the stomach [2-4]. H. pylori infection is common in both developed and developing countries. It is estimated that in developed countries 30¨C50% of the adult population is infected. In developing countries, the prevalence of H. pylori infection is noted even higher-approximately 80% [5,6]. Interestingly, not all the H. pylori infected individuals develop peptic ulcer or gastric cancer. A significant number of patients have milder form of disease, like inflammation in stomach and duodenum [7,8]. Such discriminatory behavior of H. pylori can be l %K Helicobacter pylori %K Cytotoxin and ATPase %U http://www.biomedcentral.com/1471-230X/3/31