What are the methods of thermal disinfection and what is the principle of thermal disinfection and s

1.There are four types of dry heat sterilization methods: incineration, cautery, dry roasting and infrared.

1) Incineration method: it can kill bacterial spores.

2) Cautery: Medicine|For example, in the microbiology laboratory, the flame is used to sterilize the inoculation ring and the mouth of the test tube.

3) Dry baking method: use the oven to heat to 160-170, 2 hours. Medicine|The Education Network is suitable for sterilizing glass, ceramic or metal utensils that are resistant to high temperatures.

4) Infrared: The thermal effect can only be on the surface of the irradiated object. This method is mostly used for disinfection and sterilization of medical devices and tableware.

2.Damp heat sterilization methods include pasteurization, boiling, and autoclaving.

1) Pasteurization: heating for minutes or seconds does not denature the protein, but can kill common pathogenic bacteria, and is often used for the disinfection of milk and wine.

2) Boiling method: boiling water (100) for 5 minutes at 1 atmosphere pressure can kill bacterial propagulesIf 2% sodium bicarbonate is added, the boiling point can be increased to 105 and can prevent rust, which is often used for disinfection of tableware and some medical utensils.

3) Autoclave sterilization method: apply a pressure steam sterilizer, pressurize to the temperature to reach, 15-20 minutes, medical|The education network can kill bacterial spores and all microorganisms, and is often used for the sterilization of culture media, glucose saline infusion, dressings and various high temperature and moisture resistant items.

Note: Thermal sterilization is reliable and easy to use, making it the preferred sterilization method.

Commonly used thermal sterilization methods:

1) Incineration method: incineration with fire is a very thorough sterilization method, suitable for discarded contaminated items and infectious animal carcasses.

2) Cauterization method: directly cauterized on the flame for the sterilization of the inoculation ring (needle) and the mouth of the test tube or bottle.

3) Dry baking method: After the dry oven is energized, it is sterilized with high hot air. Generally, it is heated to 160-170 degrees Celsius and maintained for 2 hours to kill all microorganisms, including spores. It is mainly used for glassware, magnets or syringes that need to be dried.

4) Boiling method: boiling for 100 minutes for 5 minutes can kill the propagules of bacteria, and it is advisable to boil for 10 minutes for general disinfection. If you need to kill the spores, boil for 1-3 hours. It is mainly used for disinfection of general surgical instruments, syringes, hoses and eating utensils.

5) Intermittent sterilization method: It is a sterilization method that uses repeated circulation steam to kill all propagules and spores of bacteria. This method is applicable to heat-resistant articles, but also to the sterilization of some substances that are not heat-resistant (<100) such as certain culture media.

The specific method is to place the items to be sterilized in the Arnold's flow-through steam sterilizer, heat 100 for 15-30 minutes to kill the bacterial propagules in it, and then place the items in the 37 incubator overnight, so that the spores develop into propagules, and then heat them through circulation steam the next day, so that all propagules and spores can be killed three times in a row. If some items are not resistant to 100, the temperature can be reduced to 75-80, the heating time can be extended to 30-60 minutes, and the number of times can be increased to more than 3 times, and the purpose of sterilization can also be achieved, such as sterilization of serum medium or yolk medium with a serum coagulator.

6) Pasteurization: Created by Pasteur, it is commonly used for the sterilization of milk and alcohol. Generally, heating for half an hour, or 15-30 seconds, can achieve the purpose of killing pathogenic bacteria or general miscellaneous bacteria without seriously damaging the quality of the articleCollected and organized by the education network.

7) Autoclave sterilization method: It is the most widely used sterilization method with the best sterilization effect. Sterilization with an autoclave pot results in a high temperature due to the high pressure saturated water vapor generated by the heating of a closed vessel, usually at a pressure of 15-30 minutes, killing all microorganisms, including bacterial spores.

This method is suitable for the sterilization of high temperature and moisture-resistant items, such as ordinary culture medium, normal saline, surgical instruments, syringes, surgical gowns, dressings and rubber gloves.

Methods of thermal disinfection and sterilization are divided into dry heat and moist heat.

Category 2. 613 What is the Mechanism of Thermal Disinfection and Sterilization?

Destroys the proteins, nucleic acids, and cell walls of microorganisms.

and cell membranes, resulting in microbial death.

614 What are the dry heat disinfection and sterilization methods?

Dry heat disinfection and sterilization methods include incineration, cautery, dry roasting, and infrared.

and microwaves, etc. 615 What is the Mechanism of Dry Heat Sterilization? (1) The high temperature of dry heat denatures the protein. (2) Microorganisms are damaged by high-temperature oxidation.

3) Electrolytes in microbial purees during dry heat processes.

Concentrate and kill microorganisms.

3) Contaminated medical equipment and articles should be disinfected first, then cleaned, and then disinfected or sterilized.

4) The disinfectant in use must maintain its effective concentration, and the disinfection effect must be regularly tested.

5) Medical personnel should understand the performance, function and use of disinfectants. Attention should be paid to the effective concentration, action time and influencing factors when formulating.

6) The sterilized medical equipment should be properly packaged and stored to prevent recontamination.

605 What are the levels of disinfectant?

Disinfection can be divided into three levels according to the type and size of the microbial killed: high-level (high-efficiency) disinfection, medium-level (medium-efficiency) disinfection and low-level (low-efficiency) disinfection.

1) Combustion method:

It is often used for items with no retained value, and can also be used for emergency use or unconditional disinfection by other methods.

2) Dry roasting method:

The special oven is used to sterilize after heating up with electricity, and the effect is reliable. It is often used in oils, powders, glassware, and medicineThe school education network collects and sorts out the sterilization of metal and ceramic products.

3) Boiling method:

It can be used for enamel, metal, glass, and rubber items that are not afraid of moisture and high temperature resistance. This method cannot be used to sterilize surgical instruments. Remove rubber items in time after disinfection to avoid softening. This method should not be used for sharp instruments to avoid heat dulling.

4) Autoclave sterilization:

It is the preferred sterilization method that is most commonly used and most reliable in hospitals. It is suitable for items that are resistant to high temperature, high pressure and humidity, and the pressure steam sterilizers commonly used in hospitals include portable pressure steam sterilizers, horizontal pressure steam sterilizers and pre-vacuum pressure steam sterilizers.

Thermal disinfectionSterilizationThe principle of the method is to use heat to coagulate and denature the proteins of microorganismsCell membranesWhen the change occurs, the enzyme loses its activity to achieve the purpose of disinfection and sterilization.

Thermal disinfection and sterilization use heat to coagulate and denature the proteins of microorganisms, change the cell membrane, and inactivate the enzyme to achieve the purpose of disinfection and sterilization.

High temperatures have a pronounced lethal effect on bacteria. Thermal sterilization includes dry heat sterilization and moist heat sterilization, which can denature bacterial proteins and electrolytes.

Concentration, moist heat sterilization can denature the protein of the cell, nucleic acid.

The advantages of degrading and damaging the cell membrane of bacteria, the advantages of moist heat sterilization are strong penetration, and the bacteria absorb water, denature, coagulation, and steam, which have the potential to be hot and auspicious.

Thermal sterilization method:

The method of killing microorganisms using high temperatures is called thermal sterilization. When high temperature acts on microorganisms, the structure of the cell membrane changes, the enzyme passivates and the protein coagulates so that the cell dies According to the relationship between the growth and development of microorganisms and temperature, microorganisms can be divided into three categories: low-temperature microorganisms and high-temperature microorganisms.

Microorganisms of different temperature types have different resistance to high temperatures, and when the ambient temperature exceeds the maximum temperature range of microbial growth, it is easy to die, and the higher the temperature exceeded, or the longer the time under high temperature conditions, the faster the microbial death.

Whether the sterilization is complete or not is generally based on killing the spores of the bacteria. Different microorganisms have different tolerance to high temperatures, generally speaking, cells in the vegetative growth period of the rock world have poor heat tolerance, and cells in a dormant state, such as various spores, have strong heat tolerance.

The temperature of thermal disinfection is 100 °C and the time is 10-15 minutes.

Boiling water or steaming is the most common thermal disinfection method, which can be maintained for 10-15 minutes under 100 conditions, which can effectively kill common bacteria, viruses and other pathogenic microorganisms.

And many disinfection cabinets on the market also use the principle of thermal disinfection.

Significance of disinfection:

1. Prevent pathogens.

Spread to society, causing epidemics to occur.

3. Prevent patients from being infected by other pathogens and complications.

Cross-contamination occurs.

4. At the same time, it also protects medical staff from infection.

Disinfection measures alone are not enough to achieve these goals. Necessary isolation measures and aseptic procedures at work must be carried out at the same time to achieve the effectiveness of infection control.

Answer]: E test point: the principle of thermal disinfection and sterilization; Analysis:

High temperature can denature or coagulate the proteins and enzymes of microorganisms, and the metabolism is greatly hindered and died, so as to achieve the purpose of disinfection and sterilization. Therefore, E is selected for this question. Error avoidance:

Some candidates in this question do not thoroughly grasp the principle of thermal disinfection and sterilization, and it is easy to choose item A wrongly, high temperature can make the protein grinding and enzyme denaturation of microorganisms cause metabolism disorders and death, this knowledge point should be understood and memorized.

a.Inhibits bacterial metabolism and growth.

b.Trapping the proteins of microorganisms and denaturing the enzymes (correct answer) CPhotolytic denaturation of the proteins of microorganisms.

d.The structure of bad bacteria or membranes.

e.Activity of bacterial enzymes.

It is a high level of disinfection.

1. Sterilization: a method that can kill all microorganisms (including bacterial dental sporin) to achieve a guaranteed level of sterilization. Methods that fall into this category are:

Physical sterilization methods such as thermal sterilization, ionizing radiation sterilization, and microwave sterilization, as well as sterilization methods for disinfection agents such as formaldehyde and hydrogen peroxide.

2. High-level disinfection method: it can kill all kinds of microorganisms, and the method of killing bacterial spores to achieve the disinfection effect This disinfection method should be able to kill all bacterial propagules (including Mycobacterium tuberculosis), viruses, fungi and their spores and most bacterial spores. Methods that belong to this category are:

Thermal, ionizing radiation, microwave and ultraviolet rays, as well as disinfection factors such as chlorine, chlorine dioxide and some compound disinfectants, are comprehensively sorted out by the medical education network.

3. Medium-level disinfection: It is a disinfection method that can kill and remove various pathogenic megatin microorganisms other than bacterial tooth spores, including ultrasound, iodine disinfectants (iodophor, iodine tincture, etc.), alcohols and chlorhexidine compounds, etc.

4. Low-level disinfection method: chemical disinfectants that can only kill bacterial propagules (except mycobacteria) and lipophilic viruses and mechanical sterilization methods such as ventilation and flushing. Such as single-chain quaternary ammonium salt disinfectants, plant disinfectants and mercury, silver, copper and other metal disinfectants.