The discovery that stomach ulcers are caused by bacteria is quite recent and was proved fairly conclusively in 1984 when the Australian scientist Barry Marshall drank a petri-dish full of the bacteria Helicobacter pylori and five days later developed serious gastritis, which cleared after antibiotic treatment. As stomach ulcers are quite common, and can be a major source of duodenal ulcers and stomach cancer, the discovery that they could be treated by a course of antibiotics was of major medical importance.
Recently, researchers from the University of Illinois have discovered a bacterial toxin that plays a part in inducing cell death, or apoptosis, in the cells of the human host. The toxin is called VacA (for vacuolating cytotoxin A) and had been shown previously to induce cell death although the mechanism was not known.
Cell death plays an important part in the development of gastric cancers. The cells die by apoptosis, which is a program of cell death built into each cell in your body. Rather than attacking the cells of the stomach lining the Helicobacter pylori releases a chemical which causes them to quietly commit suicide. In order to induce this the VacA toxin targets the mitochondria; the parts of the cell that are dedicated to producing energy.
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