PSC 432 Chapter 31: Inhibitors of cell wall synthesis
17 Feb 2019
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Document Summary
Penicillins bind to and inactivate penicillin-binding proteins (pbps) on the bacterial cell. Penicillins interfere with the last step of bacterial cell wall synthesis (transpeptidation), Many bacteria, particularly the gram positive cocci, produce degradative enzymes. Penicillins are inactive against organisms devoid of a peptidoglycan cell wall, such as: mechanism of action membrane. These are bacterial enzymes involved in the synthesis peptidoglycan. resulting in exposure of the osmotically less stable membrane. Cell lysis occurs through osmosis or activation of autolysins. (autolysins) that participate in the normal remodelling of the bacterial cell wall. In the presence of accumulated peptidoglycan precursors, autlosyins are activated and their degradative action proceeds in the absence of cell wall synthesis. This contributes to destruction of the cell wall. mycobacteria, protozoa, fungi and viruses. Pseudomonas aeruginosa lacks porins, making these organisms intrinsically resistant to many antimicrobial agents: natural penicillins: these penicillins, which include those listed as antistaphylococcal, are obtained from fermentations of the mold pencillium chrysogenum.
