[Polymorphism in Helicobacter pylori--a key function in recurrence of infection?].
Despite the fact that Helicobacter (H.) pylori is ubiquitous throughout the world, little is known at present about the source of infection and mode of transmission. Person-to-person transmission may be of importance. The fact that Helicobacter pylori can revert to a coccoid form stimulated speculation about its role in transmission and as a possible cause of reinfection in duodenal ulcer disease. Various antibacterial agents (bismuth subcitrate 32 mg/l bismuth subsalicylate 64 mg/l, amoxicillin 0.05 mg/l, ampicillin 2 mg/l, erythromycin 4 mg/l, glycochenodeoxycholic acid 423 mg/l, ursodeoxycholic acid 540 mg/l) inhibit the growth of H. pylori and stimulate the formation of coccoid structures. Ultrastructural and biochemical results show that the coccoid form meets the necessary criteria for survival. Thus, to be successful, treatment must aim not only at eliminating the vegetative form, but also at preventing the development of the coccoid form.