Polyene antibiotics are adsorbed on the cytoplasmic membrane of fungi and bind to its substance ergosterol. As a result of this process, the cell membrane loses macromolecules, which leads to dehydration of the cell and its death. This group is represented by rifampicins, which are produced by actinomycetes. Rifampicin inhibits the activity of DNA-dependent RNA polymerase, which leads to blocking of protein synthesis during the transfer of information from DNA to RNA.
The cytoplasmic membrane is located under the cell wall and is a lipoprotein (up to 30% lipids and up to 70% proteins). Antibacterial drugs that disrupt the function of the cytoplasmic membrane are polyene antibiotics (Nystatin, Levorin and Amphotericin B) and Polymyxin. Rice. 10. Damage to the membrane of a bacterial cell by antibiotics leads to its death (computer simulation). Rice. 11. The photo shows the moment of protein synthesis from amino acids by the ribosome (left) and a three-dimensional model of the ribosome of the bacterium Haloarcula marismortui (right). It is the ribosomes that often become the "target" for many antibacterial drugs.
flagyl photo shows the moment of DNA doubling at the top and the RNA molecule at the bottom. Rifampicin inhibits the activity of DNA-dependent RNA polymerase, which leads to blocking of protein synthesis during the transfer of information from DNA to RNA. Classification of antibiotics by their effect on the microbial cell.
The drugs of this group kill the bacterial cell. These include benzylpenicillin, its semisynthetic derivatives, cephalosporins, fluoroquinolones, aminoglycosides, rifampicins. Drugs in this group stop the growth of microbes. Bacteria that have not reached a certain size are not capable of reproduction and quickly die, therefore the bacteriostatic effect is equal in strength to the bactericidal one. Antibiotics in this group include tetracyclines, macrolides and aminoglycosides.