A multinational team of researchers showed that babA, a protein that helps H. pylori stay in the stomach, has evolved in many strains of the bacteria in Latin America. The protein is used by virulent strains of H. pylori that are the targets of a long-term vaccine development effort.
"If we can improve our understanding of how H. pylori adheres to the stomach lining, we may be able to develop better ways to prevent or decrease infections," says Douglas E. Berg, Ph.D., Alumni Professor of Molecular Microbiology at Washington University School of Medicine in St. Louis and a contributor to the research, which appears in the July 23 issue of Science. "H. pylori is a very clever pathogen, but its need to stick to the stomach lining may be its Achilles' heel."
Epidemiologists estimate that H. pylori infections are present in over half of the world's population. Most infections in the United States and other industrialized nations can be treated with antibiotics, but treatments are too costly for many sufferers in underdeveloped nations, where the bacteria's pervasiveness and poor sanitation significantly increase the risk of repeat infections. In addition, resistance to standard drug therapies is a major problem in these countries.
H. pylori can survive in human stomachs for decades, employing many tricks to do so. To avoid being flushed out by digestive processes, the bacteria stick to cells lining the stomach wall, from which they also steal nutrients.
BabA, one of several "adhesins" that help H. pylori stick to the stomach wall, binds to a carbohydrate structure known as the Lewis b antigen receptor. In humans with different blood types, t
Contact: Michael C. Purdy
Washington University School of Medicine