Antibiotics

The first antibiotic drug discovered by humans was penicillin, which was developed during the Second World War due to the need for effective anti-infectives. In fact, the role of these substances began to be recognized as early as the discovery of antagonistic phenomena between microorganisms in the 1970s. By 1942, SAWaksman had adopted the term antibiotics after years of observing the activity of these effects. Although penicillin has been discovered by A. Fleming in 1928, it has not been fully recognized for its importance because of the fact that this naturally-derived antimicrobial agent has been shown to be effective against human and animal systemic infections. Stress has spurred research into the fight against infectious agents, and HWFlorey and his colleague EB Chain extracted the penicillin extract and successfully demonstrated the efficacy of penicillin treatment. In 1943, Waxman discovered the second antibiotic, streptomycin, and then observed the isolated bacitracin, neomycin, polymyxin, chloramphenicol, chlortetracycline, oxytetracycline and other antibiotics. After the effect, the full importance of antibiotics is revealed. With the success of antibiotics in chemotherapy, they have also been found to have a wide range of uses in plant protection, animal husbandry, food preservation, and the like. Antibiotics are also known as "antibiotics." Generally refers to a class of substances produced by bacteria, mold or other microorganisms that have anti-pathogenic properties during their life. It is an important drug for controlling human and animal infectious diseases, anti-tumor and for controlling plant diseases and insect pests. Antibiotics are a secondary metabolite of microorganisms that, when used in low concentrations, inhibit or kill the growth and metabolism of another microorganism. Some antibiotics also have anti-tumor or other effects. Since the introduction of penicillin into medical treatment in 1940, there have been thousands of antibiotics discovered and invented, but not more than 100 clinically used. These antibiotics are extracted from the microbial culture solution or are produced by semi-synthesis or synthesis. Antibiotics are generally classified into penicillins, cephalosporins, aminoglycosides, tetracyclines, chloramphenicols, macrolides, antifungals, and antitumor according to their sources and effects. Also according to the range of antibacterial spectrum is divided into broad spectrum and narrow spectrum. The antibacterial mechanism and effects of various antibiotics vary. For example, penicillin and bacitracin can inhibit the synthesis of bacterial cell walls; peptide antibiotics can destroy the plasma membrane of bacteria; chloramphenicol, streptomycin and the like can inhibit protein synthesis or interfere with nucleic acid synthesis. Some antibiotics have a small range of action, such as penicillin, which is only effective against Gram-positive bacteria, and is called a narrow-spectrum antibiotic. Some antibiotics have a wide range of effects, such as tetracycline inhibits most bacteria, called broad-spectrum antibiotics. At present, there are more than 100 kinds of antibiotics widely used, such as penicillin, streptomycin, and gentamicin, which are commonly used in medical treatment. In agriculture, geranol and jinggangmycin have been widely used in the control of rice pathogens, scutellaria is used to control rice blast, gibberellin is used to promote plant growth and the like. However, when using antibiotics, it is necessary to target the disease and not to use it. Some antibiotics can produce some side effects, such as continuous use of streptomycin, gentamicin can cause deafness, excessive chloramphenicol can cause leukopenia. Some people also have an allergic reaction to certain antibiotics, and even fatal dangers in severe cases, so some antibiotics (such as penicillin) must be "skin test" before use. Rational drug use is a key issue in the application of antibiotics. Blind use of antibiotics, especially long-term use of broad-spectrum antibiotics, will not only lead to the emergence of drug-resistant strains, but many antibiotics have non-negligible toxic side effects, and even due to the destruction of normal flora in the body, causing serious consequences Infected." Therefore, we must strictly follow the doctor's advice. Agricultural antibiotics: Since the discovery of blasti-cidin S in the late 1950s, it has developed into a relatively large class of antibiotics. Antibacterial and antifungal antibiotics effective against crop diseases such as kasugamycin, validamycin (valid-mycin), polyoxin and actidione Wait. Some insecticidal antibiotics such as tetranectin and piercicidin have a good control effect on certain pests of crops. Some antibiotics also have obvious growth-promoting effects on plants, such as gibberellin.