The role and characteristics of antibiotics
Antibiotics are the secondary metabolic products of microorganisms. They do not participate in the cell structure or the stored nutrients in the cells. They are harmless to the producing bacteria themselves, but have antagonistic effects on some microorganisms. It is the microorganisms that defeat other microorganisms in the interspecies competition. A defense mechanism of its own. Antibiotics have characteristics different from chemical drugs:
(1) Antibiotics can selectively affect specific links in the DNA, RNA and protein composition system of bacterial cells, interfere with the metabolic effects of cells, hinder life activities or stop growth or even death . It is different from non-selective general disinfectants or disinfectants. The antibacterial activity of antibiotics is mainly manifested in three phenomena: bacteriostasis, sterilization and lysis. There is no clear boundary between these three effects. The performance of antibiotics' antibacterial effect is related to application concentration, effect time, sensitive microorganism species and surrounding environmental conditions.
(2) The effect of antibiotics is selective, and different antibiotics have different effects on different pathogens. The pathogen species sensitive to a certain antibiotic is called the antibiotic spectrum (antibacterial spectrum) of the antibiotic. For example, the sirimycin produced by Streptomyces lilacinus only has a curative effect on a few viruses, but has no effect on bacteria, fungi and most other viruses. Broad-spectrum antibiotics are effective against a variety of pathogens. For example, penicillin has outstanding efficacy against a variety of gram-positive bacteria, streptomycin has outstanding efficacy against a variety of gram-positive and negative bacteria, and has excellent efficacy against tuberculosis Special effects.
(3) Concentration of useful effects. Antibiotic is a physiologically active substance. Various antibiotics generally have an effect on pathogens at very low concentrations, which is another major feature that distinguishes antibiotics from other chemical sterilants. Various antibiotics have different useful concentrations for different microorganisms. Usually, the lowest concentration that inhibits the growth of microorganisms is used as the antibacterial strength of antibiotics, referred to as useful concentration. The lower the useful concentration, the stronger the antibacterial effect.
Useful concentrations above 100 mg/L are antibiotics with low efficacy, and useful concentrations below 1 mg/L are antibiotics with high efficacy.
(1) Antibiotics can selectively affect specific links in the DNA, RNA and protein composition system of bacterial cells, interfere with the metabolic effects of cells, hinder life activities or stop growth or even death . It is different from non-selective general disinfectants or disinfectants. The antibacterial activity of antibiotics is mainly manifested in three phenomena: bacteriostasis, sterilization and lysis. There is no clear boundary between these three effects. The performance of antibiotics' antibacterial effect is related to application concentration, effect time, sensitive microorganism species and surrounding environmental conditions.
(2) The effect of antibiotics is selective, and different antibiotics have different effects on different pathogens. The pathogen species sensitive to a certain antibiotic is called the antibiotic spectrum (antibacterial spectrum) of the antibiotic. For example, the sirimycin produced by Streptomyces lilacinus only has a curative effect on a few viruses, but has no effect on bacteria, fungi and most other viruses. Broad-spectrum antibiotics are effective against a variety of pathogens. For example, penicillin has outstanding efficacy against a variety of gram-positive bacteria, streptomycin has outstanding efficacy against a variety of gram-positive and negative bacteria, and has excellent efficacy against tuberculosis Special effects.
(3) Concentration of useful effects. Antibiotic is a physiologically active substance. Various antibiotics generally have an effect on pathogens at very low concentrations, which is another major feature that distinguishes antibiotics from other chemical sterilants. Various antibiotics have different useful concentrations for different microorganisms. Usually, the lowest concentration that inhibits the growth of microorganisms is used as the antibacterial strength of antibiotics, referred to as useful concentration. The lower the useful concentration, the stronger the antibacterial effect.
Useful concentrations above 100 mg/L are antibiotics with low efficacy, and useful concentrations below 1 mg/L are antibiotics with high efficacy.