The discovery history of Helicobacter pylori

Helicobacter pylori, referred to as Hp, is a unipolar, multiple flagella, blunt end, spiral curved bacteria. A length of 2.5 to 4.0 m, and a width of 0.5 to 1.0 m. In the gastric epithelial cell surface often has a typical spiral or arc.

Since the discovery of Helicobacter pylori (Hp) by Marshall and Warren in 1983, it has caused a great stir in the international field of digestive diseases, and its discovery has greatly promoted the development of digestive diseases, especially gastroduodenal diseases Role in China in 1985 to carry out this study. Hp research has made significant progress in the treatment of ulcer disease. Then, the study of Hp also extends to the relationship with gastric cancer. Studies have shown that Helicobacter pylori is the development of many chronic gastropathy in an important pathogenic factor. Hp and chronic gastritis, peptic ulcer, gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma is closely related. Through the understanding of basic biological characteristics of Hp, will help to explore its pathogenesis, to develop the correct treatment program and the design of the vaccine.

Physiological characteristics of Helicobacter pylori

Helicobacter pylori is a micro-aerobic bacteria, environmental oxygen requirements of 5 to 8%, in the atmosphere or absolute anaerobic environment can not survive. Many of the solid medium for H. pylori isolated culture medium, Brinell agar use more, but the need to add appropriate amount of whole blood or fetal bovine serum as a supplement to grow. Often vancomycin, TMP, amphotericin B and other components to prevent bacterial growth inhibitor bacteria.

Helicobacter pylori does not respond to most of the classical biochemical experiments commonly used to identify intestinal bacteria in clinical microbiology experiments. The enzymatic reactions of seven enzymes, such as oxidase, catalase, urease, alkaline phosphatase, r-glutamyltranspeptidase and leucylpeptidase, are the basis for the biochemical identification of Helicobacter pylori.

Barry Marshall and Robin Warren drank a culture of Helicobacter pylori, which was soon followed by stomach trouble.

Molecular biological characteristics of Helicobacter pylori

The complete gene sequence of Helicobacter pylori has been determined, in which the urease gene has four open reading frames, UreA, UreB, UreC and UreD. The polypeptides encoded by UreA and UreB are structurally equivalent to the two subunits of the urease structure. Helicobacter pylori urease is extremely rich, about 15% of the bacterial protein, activity is equivalent to 400 times Proteus. Urease catalyzes the hydrolysis of urea to form "ammonia cloud" to protect the bacteria in the presence of high acid environment. In addition, there VacA gene and CagA gene, respectively, encoding vacuolating toxins and cytotoxin associated proteins. According to the expression of these two genes, Helicobacter pylori strains in turn divided into two main types: Ⅰ type contains CagA and VacA gene and express two proteins, Ⅱ type does not contain CagA gene, does not express two proteins, there are some As the intermediate expression, which expresses one of the virulence factors. Now more that type Ⅰ and gastric disease are more closely related.

Helicobacter pylori transmission

Oral transmission: China's traditional feeding, parents will chew the food after feeding the child, if the parents suffering from chronic gastritis, bacteria will be fed through the mouth of the way the pollution to the child.

Kiss between lovers: Helicobacter pylori is widely found in the infected person's saliva, plaque. Contact with infected persons saliva, food consumption by Helicobacter pylori contamination of food can cause infection.

Sneezing: patients with sneezing can be discharged through the nasal cavity with Helicobacter pylori, and there is a strong smell, need to be distinguished from oral inflammation.

Helicobacter pylori infection symptoms

1) Helicobacter pylori infection symptoms are mainly acid, heartburn and stomach pain, bad breath. This is mainly due to Helicobacter pylori induced gastrin secretion, and the occurrence of heartburn heartburn, and patients with gastric ulcer disease, Helicobacter pylori is caused by the occurrence of the main symptoms of stomach pain, bad breath, one of the most direct bacteria is the pyloric screw The bacteria. [2]

2) Helicobacter pylori can cause chronic gastritis. Occurrence of the main clinical manifestations are: upper abdominal discomfort, pain, and sometimes belching, acid reflux, nausea, vomiting symptoms, the course is relatively slow, but easy to recurrent.

3) patients infected with Helicobacter pylori produce a variety of pathogenic factors, causing gastric mucosal damage, the occurrence of clinical disease diversity, and patients will appear more acid reflux, belching, fullness, etc., are infected with pyloric screw Of patients with H. pylori were many times greater than those without H. pylori infection.

4) Helicobacter pylori infection is generally not particularly obvious symptoms, this time generally through the check to determine whether the Helicobacter pylori infection, Helicobacter pylori this pathogen, it is easy to induce gastrointestinal disease. Helicobacter pylori symptoms which is the performance of these.

Methods for the examination of Helicobacter pylori

Urea breath test: Hp has a strong endogenous urease, can break down the stomach and radionuclide labeled urea, produce CO2 and NH3, CO2 is absorbed by the lung exhaled, so just analyze the expiratory 14C or 13C can diagnose the presence of Hp.

Urea breath test - the principle is HP in the body produces urease, with 13C or 14C labeled urea after the dose taken by the subject, that is decomposed to produce carbon dioxide with isotope-tagged, collected breath specimen, with a liquid scintillation counter or Gas nuclide mass spectrometry detection of labeled carbon dioxide, high sensitivity, quantitative, non-traumatic patients without pain, simple and rapid method, whether the radical detection of HP is very reliable. Sensitivity 95%, specificity 95% - 100%.

Blood test: blood test is the method used to detect serum levels of antibodies to H. pylori. The human body in the infected by Helicobacter pylori, will produce antibodies in the body, because of this, so there will be the following two questions, resulting in inaccurate results.

Treatment of Helicobacter pylori

Helicobacter pylori positive treatment options include two categories, are basically commonly used drugs, a class of bismuth-based formulations, such as proton pump inhibitors. The other is Wei Shuyuan compound probiotic microbiology of the new program, coupled with the two antibiotics, the most commonly used amoxicillin, then metronidazole, we often use the program is the three programs.