5. want to serum medium sterilization, it is appropriate to use A. intermittent sterilization B. pasteurization C. autoclave sterilization D. circulating steam sterilization E. ultraviolet light Irradiation 6. The most commonly used and effective method to kill bacterial germ cells is A. ultraviolet irradiation B. dry-roasting sterilization C. intermittent sterilization D. circulating steam sterilization E. autoclave sterilization 7. The best effect of moist-heat sterilization is A. autoclave sterilization B. circulating steam C. intermittent sterilization D. pasteurization E. boiling method 8. B.95% C.75% D.50% E.30% 9.About ultraviolet light, which of the following is not correct A. can interfere with the synthesis of D.NA. B. Disinfection effect is related to the time of action C. Commonly used in the air, the surface of the goods to disinfect D. irritation to the eyes and the skin E. Penetrating power 10.On the principle of the disinfectant action is to A. make the bacterial protein denaturation B. to make the bacterial protein coagulation C. to make the bacterial enzyme Inactivity D. Destruction of bacterial cell membranes E. All of the above are correct 11. ultraviolet sterilization principle is A. destruction of bacterial cell wall peptidoglycan structure B. so that the bacterial protein denaturation coagulation C. destruction of D.NA. configuration D. affect the permeability of the cell membrane E. and the combination of bacterial nuclear proteins 12. serum, antitoxin, etc. can be used in which of the following methods of sterilization A. Heating 56 ℃ for 30min B. ultraviolet light irradiation C. Bacterial filter filtration D. High-pressure steam sterilization E. Pasteurization 13. The main basis for determining whether disinfection sterilization is complete is A. propagules are completely eliminated B. Germ cells are completely eliminated C. Flagellar protein denaturation D. Bacteriophage D. NA. denaturation E. None of the above 14. The cause of dysbiosis is ( ) A. Ecological agents used in large quantities B. Normal flora of the genetic characteristics of the obvious changes in the C. Normal flora of drug resistance obviously changed D. Normal flora of drug-resistant bacteria obviously changed D. the proliferation of normal flora E. the composition and number of normal flora 15. The description of normal flora is correct ( ) A. Under normal circumstances, normal flora is beneficial to the human body B. Dysentery bacilli in the intestinal tract can produce alkaline substances to antagonize other bacteria C. Normal flora in the oral cavity are mainly aerobic D. Even healthy fetuses carry normal flora E. Even healthy fetuses carry normal flora D. Normal flora in the oral cavity are mainly aerobic D. Even healthy fetuses carry normal flora E. Even healthy fetuses carry normal flora E. Even healthy fetuses carry normal flora E. Even healthy fetuses carry normal flora D. Even healthy fetuses carry normal flora D. Even healthy fetuses carry normal flora E. E. The types and numbers of normal flora remain stable throughout a person's life. 16. The incorrect description of dysbiosis is ( ) A. The further development of dysbiosis, resulting in a series of clinical symptoms and signs can be called dysbiosis B. Dysbiosis is also known as alternating flora or dual infection C. Long-term use of antibiotics will change the resistance of members of the normal flora, thus causing dysbiosis D. Dysbiosis can be caused by the use of antibiotics for a long period of time. D. Ecological agents can be used to treat dysbiosis E. Endocrine disorders can also cause dysbiosis 17. Laboratory equipment commonly sterilized by dry baking method is ( ) A. glassware B. pipette head C. bacterial filters D. scalpels, scissors E. rubber gloves 18. On the boiling disinfection method, which of the following is wrong ( ) A. Boiling 100 ℃ for 5 minutes can kill bacterial propagules B. can be used for general surgical instruments, syringes, and other equipment. Used for general sterilization of surgical instruments, syringes, needles C. Adding 1-2% sodium bicarbonate in water can raise the boiling point to 105 ℃ D. Commonly used in the disinfection of eating utensils E. Not enough to kill all bacteria. 19. the method of killing pathogenic microorganisms on the surface of the object is called () A. sterilization B. antiseptic C. aseptic operation D. disinfection E. aseptic 20. neosporin is used for disinfection of the skin surface of the commonly used concentration is () A.0.01 ~ 0.05% B.0.05 ~ 0.1% C.1 ~ 5% D.10% E.2% four, questions and answers 1.Try to describe the factors affecting the effectiveness of the action of chemical disinfectants. 2. Describe the principles and types of moist heat sterilization 3. Briefly describe the beneficial effects of normal intestinal flora on the body. 4. what is dysbiosis and dysbiosis and what is its mechanism? ANSWERS: I. Nouns Answers 1. sterilization kills pathogenic microorganisms on an object but does not necessarily kill bacterial germ cells, such as alcohol used for injections. 2. sterilization: a method that kills pathogenic microorganisms (including pathogens, nonpathogens, propagules, and germ cells) on all of an object, such as autoclaving. Requirements are higher than sterilization. 3. Antiseptic: prevent, inhibit the growth and reproduction of bacteria in vitro method, bacteria generally do not die. Such as chemical additives in food. 4. Asepsis: the absence of live bacteria in an object or on the surface of an object. 5. Aseptic operation: refers to the operation method to prevent microorganisms from entering the human body or other objects. Surgery, interventional therapy, etc. in medical treatment. 6. Normal flora: microorganisms of different types and numbers that settle on the surface of the human body and in open cavities. 7. Dysbiosis: the number and composition of normal flora among the obvious changes that is dysbiosis, mostly seen in the long-term use of antibiotics. Answers to fill in the blanks 1. destroying bacterial proteins, inhibiting or interfering with the enzyme system of bacteria and changing the permeability of cell membranes. 2. cauterization, dry roasting and incineration. 3. milk and alcohol. 4. boiling, pasteurization, autoclaving, intermittent sterilization, circulating steam sterilization. 5. Interference with bacterial D.NA. synthesis, mutation and death. 6. protection, attenuation 7. autoclave sterilization. 8. ultraviolet sterilization. 9. silver nitrate 10. gentian violet. 11. propagules, concentration, time of action. 12. concentration and duration of action, species and number of microorganisms, effect of organic matter in the environment on disinfectants, antagonism between disinfectants. 13. chlorine, bleach 14. excreta, ground 15. carbolic acid, lysol III. ANSWERS TO SINGLE-CHECK QUESTIONS 1. The main factors affecting the effect of chemical disinfectants are: (1) the concentration of the disinfectant and the time of action: the greater the concentration of the disinfectant, the longer the time of action, the better the bactericidal effect. However, it should be noted that the exception, alcohol in 70 ~ 75% of the strongest effect of sterilization, and its concentration is too high, will make the surface of the bacteria protein coagulation, so that the alcohol can not penetrate the bacteria to play a role in the internal. (2) Temperature and pH: Usually, the bactericidal effect of disinfectants is enhanced when the temperature rises. The bactericidal effect of disinfectants is also related to pH. Different disinfectants have different optimal pH, such as phenolic disinfectants are more effective in acidic environment. In addition, bacteria are more resistant at the appropriate pH, and if they deviate from their optimal pH, the bacteria will be easily killed. (3) Types and number of bacteria: Different types of bacteria have different sensitivities to disinfectants. The larger the number of bacteria, the higher the concentration of disinfectant required and the longer the action time. Therefore, the type and concentration of disinfectant should be selected according to the type and number of bacteria. (4) Influence of organic matter and other antagonists in the environment: Different chemical disinfectants have their own antagonistic substances. Bacteria are also often mixed with organic matter such as blood, sputum and pus. These mixtures can bind to the disinfectant and thus affect the bactericidal effect of the chemical disinfectant.2. Describe the principles and types of moist-heat sterilization Principles: coagulation and denaturation of bacterial corpuscular proteins; degradation of bacterial nucleic acids; and damage to the plasma membranes of bacteria. Category: (1) boiling method: boiling for 10 minutes can achieve the purpose of sterilization, if you need to kill the spores, you should extend the time to 1-3 hours. It can be used to sterilize surgical instruments, syringes, hoses and so on. (2) Circulating steam sterilization method: it is to disinfect with water steam at 100℃ under normal pressure, usually 10-15 minutes can kill the bacterial propagation body, but it is not guaranteed to kill the spores. (1) Intermittent sterilization method: the use of repeated circulation of steam heating, can kill all the bacterial propagules and spores, mainly used for heat-resistant substances, such as some nutrient culture medium sterilization. (2) High-pressure steam sterilization: the best sterilization effect, the most widely used sterilization method. Usually the pressure is 1.05kg/cm2, the temperature is 121.3℃, lasting 15-30 minutes. It can kill all microorganisms including bacterial spores. This method is suitable for the sterilization of high temperature and moisture resistant items, such as saline, general culture media surgical instruments. (3) Pasteurization: Heating 61.1-68.8°C for 30 minutes or 71.7°C for 15-30 seconds can kill pathogenic and acrobatic bacteria in the articles without destroying the quality of the articles. Such as the sterilization of milk and alcohol. 3. Briefly describe the beneficial effects of normal intestinal flora on the body. (1) Defense against foreign pathogenic bacteria: such as the composition of human intestinal mucosal surface to form a biological barrier to prevent the invasion of pathogens and adhesion. Acidic metabolites of normal flora, resulting in an acidic environment in the intestine, inhibiting the growth of pathogens. (2) Nutritional role: participate in the host's nutritional metabolism and absorption. Synthesize essential vitamins, such as niacin, biotin and pantothenic acid. (3) Immunity: immune function of the body includes: promoting the development and maturation of the immune system; as a non-specific antigen to stimulate the body's immune response; enhance the activity of immune cells. (4) Anti-tumor effect: it can produce some enzymatic metabolites to act on carcinogens; inhibit the synthesis of nitramine or degrade nitramine; as an antigen or immune adjuvant to stimulate the immune system, enhance the body's non-specific and specific immune function. 4. What is dysbiosis and dysbiosis and what is its mechanism? Between normal flora, host and external environment as well as among the members of normal flora, they are in dynamic equilibrium under normal conditions. Once this balance is broken, the composition and number of normal flora have obvious changes in the occurrence of dysbiosis, if the further development of a series of clinical symptoms and symptoms, it is called dysbiosis. Mechanisms are: (1) long-term use of antibiotics, especially the long-term use of broad-spectrum antibiotics, in the inhibition of pathogenic bacteria at the same time also inhibit the normal flora of sensitive bacteria, so that drug-resistant bacteria overpopulation, the emergence of bacterial dysbiosis. (2) low body immunity or endocrine disorders: malignant tumors, long-term diabetes and other diseases make the whole body or local immune function is low, resulting in the overgrowth of certain bacteria in the normal flora, the formation of flora dysbiosis.