Know the bacteria around us
Know the bacteria around us
□ Wen/ Zhang Tao
Bacteria and protozoa are everywhere around us, and they can be found everywhere in our home, such as carpets, beds, remote controls, shower curtains, and even the freezer with frost. Only mold, scientists have found that the total number is insixMore than ten thousand kinds. Every gram of soil in the garden is on average100Ten thousand molds. When the mold matures, there will be many spores, which will fly in the air and then stick to us or pets and be taken home.
Black grape ear mold, saprophytic killer
Mold means "moldy fungus",Eukaryotes, close relatives of mushrooms, are all filamentous fungi that can cause food mildew. Fungi have a complete nucleus, and yeasts, Aspergillus and Penicillium all belong to fungi. Mushrooms that we eat every day, as well as Chinese herbal medicines such as Cordyceps sinensis and Ganoderma lucidum, belong to macrofungi. Grape ear mold is a saprophytic mold, which widely exists in the environment and can produce a variety of toxins, which will cause serious harm to human health. existtwentycentury30In Europe in the 1990 s, many newborn babies died of pulmonary hemorrhage caused by black grape ear mold. Not only on food, but also on the bathroom wall, washstand and even the inner wall of toilet, there are a lot of molds. Researchers have found that some families have it in every cubic meter of air.600A colony.
Black grape ear mold likes to breed on wet walls, saprophytic on all kinds of vegetables piled up for a long time and open condiments, which has chronic toxic effects on people and animals and even leads to lung inflammation. Therefore, when preserving vegetables and foods at home, attention should be paid to keeping them dry and storing them at low temperature to prevent mold growth; Fermented foods such as sauce, stinky tofu, soy sauce, beer, bread, etc. should be properly sealed to avoid being contaminated by toxic fungi such as black grape ear mold. It is not difficult to deal with black grape ear mold. It can be removed with disinfectant or bleaching powder in daily life to prevent them from breeding and spreading.
Psychrophilic bacteria, refrigerator residents
The refrigerator is not only a sterile fresh-keeping room insulated from the outside world, but also easily becomes a "hotbed" of psychrophilic bacteria. As their name suggests, these psychrophilic bacteria like cold environment. The reason why psychrophilic bacteria can survive and reproduce below freezing point is that they have a special lipid cell membrane. This kind of cell membrane can chemically resist the hardening caused by extreme cold, which makes the protein in the cell show "frost resistance". Below zero.10To℃twentyUnder the environment of℃, the metabolic processes of these microorganisms can be carried out in an orderly manner. Psychrophilic bacteria will attach themselves to the frozen packaging of supermarkets and even various foods, thus entering your refrigerator.
Eating food contaminated by psychrophilic bacteria can lead to nausea, vomiting, abdominal pain, diarrhea and other symptoms. Listeria monocytogenes, a member of psychrophilic bacteria family, can also cause purulent meningitis in newborns and infants, septicemia in adults, abortion in pregnant women and so on. So, how to prevent psychrophilic bacteria from polluting food? The weakness of psychrophilic bacteria is that they are not heat-resistant. Therefore, it is a good way to expel these microorganisms by defrosting the refrigerator at home regularly and cooperating with disinfection measures. besides,Food taken out of the refrigerator must be heated thoroughly. Finally, raw and cooked foods should be stored separately to avoid cross-contamination.
Of course, psychrophilic bacteria are not useless. Their unique anti-freezing characteristics have inspired many scientists, made people understand a new anti-freezing mechanism, and pointed out a new research direction for the problem that food crops are difficult to survive in cold regions.
Staphylococcus, a close friend of human beings.
Staphylococcus is the closest microorganism to human beings. As long as the human body can directly contact with them, they can be found almost everywhere. Some species, such as Staphylococcus epidermidis, even "live" on our skin directly. These microorganisms are spherical, but they like to pile up in large numbers to form grape clusters. The most well-known staphylococcus aureus is the chief culprit of traumatic infection. The strong smell of disinfectant in the hospital is to prevent the bacteria from multiplying and accumulating, causing infection. Poisoning caused by the corruption of dairy products and meat is also caused by enterotoxin produced by staphylococcus in the process of proliferation.
Little known is that staphylococci have made an important contribution to immunological research. For example, protein isolated from the cell wall of Staphylococcus aureus can specifically bind to antibody proteins, and become an indispensable tool in various immune response studies.
Although staphylococcus is everywhere, human beings have certain natural immunity to pathogenic staphylococcus. Only when the skin mucosa is injured or the immunity of the body is reduced, it is easy to cause infection. There is a certain amount of staphylococci in the environment, but it will always stimulate the immune system of the human body and maintain its activity. Therefore, paying attention to these microorganisms should not be aimed at completely eliminating them, but it is more important to strengthen self-exercise and improve immunity.
Helicobacter pylori, a master of survival
Helicobacter pylori was first discovered by Barry Marshall and Robin Warren, so it was obtained.2005Nobel Prize in Physiology or Medicine. Helicobacter pylori is the only known gastric bacteria in human beings. Previously, the medical community has always believed that no bacteria can survive in a strong acid environment in the stomach for a long time.1994In 2006, the World Health Organization designated Helicobacter pylori as a class I carcinogen.
Helicobacter pylori is highly contagious and can be transmitted through hands, unclean food, unclean tableware and feces. Therefore, good hygiene habits should be developed in daily diet.,Prevent infection. Under normal circumstances, the stomach wall has a series of perfect self-protection mechanisms, which can resist the invasion of thousands of microorganisms through the mouth. Since Helicobacter pylori was found on the surface of gastric mucosal epithelial cells, it was realized that Helicobacter pylori was almost the only culprit that could break through this natural barrier.
As the only known bacteria living in human stomach, Helicobacter pylori can cause gastric ulcer, and a large number of studies have shown that it exceeds90%Duodenal ulcer and80%The left and right gastric ulcers are all caused by Helicobacter pylori infection. In recent years, it has also been found that Helicobacter pylori is not only related to chronic gastritis, peptic ulcer and gastric cancer, but also can cause other organ and tissue diseases, especially cardiovascular diseases, anemia and idiopathic thrombocytopenic purpura. Helicobacter pylori is very stubborn. Once infected, the self-healing rate is close to zero unless a formal treatment scheme is used.
There are two main challenges for Helicobacter pylori to break through the gastric wall barrier: first, they must survive in corrosive gastric juice; Second, they must pass through the thick mucus layer and reach the most suitable living environment-the gastric epidermal cell layer. Helicobacter pylori neutralizes the acidity of hydrochloric acid in the stomach by secreting urease. Biologists have always assumed that Helicobacter pylori gets power to pass through mucus by rotating flagella. however2009In, when scientists stopped supplying urea to Helicobacter pylori in the laboratory, they found that under this condition, Helicobacter pylori could not continue to move in the simulated mucus. Studies have shown that the chemical reaction of neutralizing gastric acid also changes the conformation of protein in mucus, making it change from a gel close to solid to a fluid more suitable for Helicobacter pylori to move.
There are many organisms like Helicobacter pylori scattered around us and in our bodies. They are extremely tiny, but they have formidable physical strength, but we often ignore them. If we really look around with a microscope, the large number of unknown family members may scare us into running away and giving up our warm home. In fact, we don’t have to be so alarmed. Members who have been classified as harmful, of course, we should concentrate on eliminating them, but other appropriate microorganisms will stimulate the human immune system and improve our immunity. As long as we can keep the family living environment clean and ventilated, clean regularly and clean up the dead corners of refrigerators, shower curtains and other places, it is not difficult to control these family members within the range of living in harmony with human beings.
