Sterilization, disinfection, antibacterial, antibacterial, unclear?
What is sterilization (sterilazation, sterilant)? Refers to the process of using strong physical and chemical factors to kill or remove all pathogenic and non-pathogenic microorganisms in the external environment, including bacterial spores and fungal spores. It is an absolute concept. The effect is expressed by the sterilization rate, generally ≥99.9999%. Commonly used physical sterilization methods include high temperature sterilization, ultraviolet sterilization, ionizing radiation sterilization, plasma sterilization bacteria, and chemical sterilization (such as ethylene oxide gas, formaldehyde vapor, peroxyacetic acid, etc.) Sterilization by radiation. For example, hospitals, clinics, and laboratories must regularly sterilize heat-sensitive materials, such as thermometers, lens instruments, polyethylene tubes, catheters, and reusable medical and dental equipment. This is cold sterilization. In essence, sterilization can be divided into two different types: sterilization and bacteriolysis. Sterilization generally means that the dead cells are not lysed and the total cell number remains unchanged, while lysis kills the cells by lysing the cells, thereby affecting the number of viable cells and the total cell number.
What is disinfection (disinfection, disinfectant)? It is used to kill pathogenic microorganisms on the transmission medium to make it harmless, but it may not necessarily kill the spores. If the artificially contaminated microorganisms can be reduced by 99.9% or the contaminated natural microorganisms on the disinfected object can be reduced by 90%, the disinfection is qualified. Relative to sterilization, it is relatively mild, basically harmless to the object being sterilized, and is not sterile.
Bacteriostasis (bacteriostasis) refers to the process of using physical and chemical methods to inhibit or hinder the growth, reproduction and activity of bacteria, but they cannot be killed. Bacteriostatic agents are usually inhibitors of some important biochemical processes, such as protein synthesis and binding. If the agents are removed, cells can resume growth. For example, anti-corrosion is a measure to prevent Pythium in food and biological products through antibacterial action. Measures include low temperature, hypoxia, dryness, hypertonicity, high acidity, and the addition of preservatives.
So what is antimicrobial activity (antimicrobial activity)? It's a bit confusing here! Antibacterial actually has a general meaning, referring to the process of killing bacteria or hindering the growth and reproduction of bacteria and their activity, so it includes processes such as sterilization, disinfection, antibacterial, anti-mildew, and antiseptic.
How to determine the antibacterial activity? It can be determined by measuring the minimum dose of the agent required to inhibit the growth of the test microorganism, and this value is called the minimum inhibitory concentration (MIC). One way to determine the MIC of a drug is to inoculate a strain into a test tube. The test tube contains a series of concentrations of the drug. After culture, the turbidity of the strain is measured. MIC refers to the lowest concentration of antibacterial agent that completely inhibits growth. The antibacterial activity can also be tested with a solid culture medium. A certain amount of antibacterial agent can be dropped on the filter paper disc and placed on the surface of the agar plate. During the culture process, the reagent diffuses from the disc to the agar, establishing a concentration gradient, and after a period of incubation, a growth inhibition zone is formed around the disc. The zone of inhibition is related to many factors, including the concentration, solubility and diffusion coefficient of the antibacterial agent, and efficiency.
Many factors affect the efficacy of chemical antibacterial agents. For example, antibacterial agents can be combined and inactivated by organic substances. It is much more difficult to disinfect kitchen countertops filled with food than clean countertops; bacteria often form biofilms to slow down or even completely prevent the penetration of antibacterial agents. Therefore, the effect of any antibacterial drug must be determined according to the actual conditions of use.
There are many types of disinfectant products in life, especially during the epidemic, the use of disinfectants has also increased significantly. We use various disinfectants for indoor disinfection, tableware cleaning, clothes washing and disinfection, and hand washing. Excessive and improper use may not achieve the disinfection effect, and will cause waste and possible harm. In addition, the extensive use of disinfectants also increases their concentration in the environment, causing certain ecological risks. Research in this area is still in its infancy.
