Gastric habitation by Helicobacter pylori: insights into acid adaptation

• Published in: Trends in pharmacological sciences (Regular ed.) Vol. 21; no. 11; pp. 413 - 416
• Main Authors: Sachs, George, Scott, David, Weeks, David, Melchers, Klaus
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2000
• Subjects: Animals; Bacterial Proteins - genetics; Helicobacter Infections - microbiology; Helicobacter pylori; Helicobacter pylori - enzymology; Helicobacter pylori - genetics; Helicobacter pylori - growth & development; Humans; Hydrogen-Ion Concentration; Membrane Transport Proteins; Stomach - microbiology; Urease - metabolism
• ISSN: 0165-6147; 1873-3735
• DOI: 10.1016/S0165-6147(00)01554-6

Bacteria have developed remarkable mechanisms to withstand hostile environments and, on occasion, select hostile environments to avoid competition. The habitation of the human stomach by Helicobacter pylori is an example of the latter. This organism is of medical interest because it causes peptic ulcer disease and predisposes to gastric cancer. The means whereby this bacterium resists gastric acidity is not only of biological interest but provides a natural pharmacological and therapeutic target for its eradication. Recent studies have shown that acid-induced activation of a urea channel regulates intra-bacterial urease activity, which enables maintenance of the pH of the periplasm of the bacteria within viable limits during gastric acidity. This appears to be an adaptation mechanism that is unique to Helicobacter species. Because no other organism inhabits the normal human stomach, targeting of drugs to these acid resistance mechanisms should provide an antibiotic that is selective for H. pylori..