Published on February 28, 2008
Helicobacter pylori and gastric ulcers: Helicobacter pylori and gastric ulcers Slide2: Helicobacter pylori (H. pylori) is a spiral shaped bacterium that lives on the lining of the stomach, and is the major cause of nine out of ten ulcers. Slide3: The stomach contains a thick mucus layer, used to protect against its own gastric juices, which can degrade food, bacteria, and viruses. H. pylori is able to survive in the stomach by taking advantage of the protective mucus layer, and living in it. Slide4: H. pylori is able to fight off the stomach acid that does reach it with the enzyme urease. Urease converts urea into bicarbonate and ammonia, which are strong bases. These acid neutralizing chemicals around the H. pylori protect if from the acid in the stomach. Slide5: H. pylori can also survive because the body’s natural defenses cannot reach the bacterium in the mucus lining of the stomach. The immune system responds to an H. pylori infection by sending white cells, killer T cells, and other infection fighting agents, but they cannot reach the infection because they cannot easily get through the stomach lining. Transmission: Transmission It is thought that H. pylori is transmitted orally by ingestion of food or water contaminated with fecal matter. It is possible that H. pylori could be transmitted from the stomach to the mouth through gastro-esophagal reflux, or burping, and could then be transmitted through oral contact. Diagnosis: Diagnosis There are three diagnostic tests that can be done to test for the bacteria. *Breath tests *Blood tests *Endoscopy Breath Tests: Breath Tests There are two forms of the diagnostic breath test, the Carbon-14 and the Carbon-13 urea breath tests. In the C14 test the breath sample is read in a scintillation counter. In the C13 test the breath sample is read in a mass spectrometer. The reaction of urea Hydrolysis is important for diagnosis of H. pylori by the breath test. Blood test & Endoscopy: Blood test & Endoscopy A blood test can also be done to test for antibodies which stick to H. pylori. An endoscopy is another diagnostic test for H. pylori where a biopsy is taken and tested for the bacterium using a gram stain. Symptoms: Symptoms The main symptom is a burning or gnawing pain in the epigastrum, usually when the stomach is empty, between meals, or in the early morning. These symptoms can last for minutes to hours and may be relieved by eating or taking antacids. Treatment: Treatment Antibiotics such as amoxicillin or tetracycline are used to cure ulcers. Therapy is 1-2 weeks of one or two antibiotics and a medicine that will reduce the acid in the stomach. The acid suppressor is paired with the antibiotics because it helps alleviate ulcer-related symptoms, and helps heal gastric mucosal inflammation. Vaccines: Vaccines Vaccines are being tested on animals and humans, but currently there are no vaccines for the prevention of H. pylori. Long-term consequences of H. pylori infection?: Long-term consequences of H. pylori infection? Recent studies show an association between long-term infection with H. pylori and the development of gastric cancer. Although this is more common in countries like Columbia and China where H. pylori infects over half of the population in early childhood.