Campylobacter pylori: a newly recognized infectious agent in the gastrointestinal tract.

Recent experience with the gastritis-associated organism Campylobacter pylori is reviewed, placing special emphasis on pathologic aspects. C. pylori is a spiral, gram-negative, urease-producing bacillus that has been found to infect the stomach in many people. C. pylori organisms are readily seen overlying the gastric epithelium, often in large numbers. Demonstration in gastric biopsies with silver stains is most vivid, but other faster, simpler stains such as Giemsa, acridine orange, and, at times, hematoxylin-eosin are satisfactory for routine purposes. The frequent occurrence of C. pylori in persons with chronic active gastritis has been confirmed in medical centers around the world. In addition, epidemiological, serological, pathological, and clinical observations suggest that C. pylori infection occurs in stomachs of duodenal ulcer patients with a frequency approaching 100%, and the infection may be relevant to pathogenesis or therapeutic response in duodenal ulcer disease. C. pylori probably also causes an acute infectious gastritis associated with hypochlorhydria. C. pylori still requires extensive investigation to establish its pathogenic role in upper gastrointestinal disorders, but evidence continues to accumulate that such a role exists and that it may be important.