Antibiotic bacterial resistance

The discovery and application of antibiotics is a great revolution of mankind. However, with the widespread use of antibiotics in clinical practice, drug resistance soon emerged, which not only caused a crisis in the use of antibiotics, but also posed a serious threat to human health once again with the emergence of "super drug resistant bacteria". [1]

Medical researchers point out that about 50% of antibiotics in the world are abused every year, while the proportion in China is even 80%. In China, India, Pakistan and other countries, antibiotics are usually available without a prescription, which has led to the abuse and misuse of antibiotics by ordinary people to some extent. Local doctors have to use more effective antibiotics when treating patients, which once again leads to stronger drug resistance of bacteria. It is precisely because of the abuse of drugs that bacteria quickly adapt to the environment of antibiotics, and various "superbugs" have been born.

The resistance of bacteria to antibiotics (including antibacterial drugs) mainly has five mechanisms: to decompose or inactivate the antibiotics, that is, bacteria produce one or more hydrolases or inactivating enzymes to hydrolyze or modify the antibiotics entering the bacteria to inactivate them; Change the target of the antibacterial action, that is, the structure of the target of the antibiotic (such as nucleic acid or nucleoprotein) changes due to the mutation of the bacteria itself or the modification of some enzyme produced by the bacteria, so that the antibacterial cannot play its role; Changes in cell characteristics, that is, changes in bacterial cell membrane permeability or other characteristics make it impossible for antibacterial agents to enter cells; The bacteria produce drug pump to pump the antibiotics entering the cell out of the cell, that is, an active transportation mode produced by the bacteria to pump the drugs entering the cell out of the cell; Change metabolic pathways, such as sulfonamides and para aminobenzoic acid (PABA), compete with dihydropterate synthetase to produce bacteriostasis. For another example, after Staphylococcus aureus has been exposed to sulfonamides for many times, its PABA production increases, reaching 20~100 times of that of the original sensitive bacteria. The latter competes with sulfonamides for dihydropteric acid synthetase, reducing or even eliminating the effect of sulfonamides. [1]

In addition, the DNA pollution caused by the abuse of antibiotics is another major factor contributing to the "superbacteria". The rapid growth of the types and numbers of bacterial drug resistance genes cannot be explained by the random mutation of organisms. Bacteria can not only exchange genes within the same species, but also between different species, and even obtain genes from the DNA scattered by the dead same species. Therefore, the rapid spread of drug resistance genes among bacteria further promoted the production of "superbugs".