02.09 Mechanisms of Antimicrobial Agents

Join NURSING.com to watch the full lesson now.

Included In This Lesson

Outline

Overview

  1. Mechanisms of Antimicrobial Agents

    1. Inhibition of cell wall synthesis- integreticy of the cell wall weakens protection, allows water to enter the cell lyses.
      1. Beta Lactam anitbiotics use this technique
        1. ex. penicillins and cephalosporins
      2. Miscellaneous
        1. Vancomycin, fosfomycin, and bacitracin
    2. Inhibition of RNA/DNA synthesis- Kills bacteria by blocking transcription of it’s RNA or replication of it’s DNA
      1. Rifamycins-bind to RNA polymerase enzyme of many bacteria
        1. Rifampin
      2. Quinolones and Fluoroquinolones- bind to DNA polymerase specific to bacteria
        1. Ciprofloxin
    3. Inhibition of general metabolic pathways
      1. Sulfa Drugs- inhibit bacteria’s ability to make folic acid.
        1. Trimethoprim
    4. Disruption of Cytoplasmic Membrane- lipophilic, detergent-like antibiotic that interacts with the lipopolysaccharide membrane.
      1. Polymyxins- Not bacteria specific, so usually just topical.
        1. Neosporin
    5. Inhibition of Protein Synthesis- bind to bacterial ribosomes
      1. Aminoglycosides- block proofreading allow the bacteria to make misshaped membrane proteins
        1. streptomycin
        2. kanamycin
      2. Tetracyclines- Block tRNA binding to ribosome and inhibits protein synthesis

 

Transcript

Today we’re going to be talking about the mechanisms of antimicrobial agents.

 

So in this lesson we are going to cover 5 main ways that antimicrobial drugs work. Inhibit synthesis of cell walls, synthesis of RNA/DNA, inhibit metabolic pathways, disrupt the cell membrane or inhibit protein synthesis. 

 

Inhibition of cell wall synthesis- integrity of the cell wall weakens protection, allows water to enter and then the cell lyses. In essence it’s like putting holes in a dam.

Beta Lactam antibiotics use this technique ex. penicillins and cephalosporins as well as other Miscellaneous antibiotics like Vancomycin, fosfomycin, and bacitracin.  

 

Inhibition of RNA/DNA synthesis- Kills bacteria by blocking transcription of it’s RNA or replication of it’s DNA. No instructions or copy of instructions the cell ceases to function.

Rifamycins-bind to RNA polymerase enzyme of many bacteria ex. Rifampin.  Whereas  Quinolones and Fluoroquinolones- bind to DNA polymerase specific to bacteria  ex. Ciprofloxin. 


Inhibition of general metabolic pathways. Sulfa Drugs- inhibit bacteria’s ability to make folic acid. ex. Trimethoprim.

 

Disruption of Cytoplasmic Membrane- lipophilic, detergent-like antibiotic that interacts with the lipopolysaccharide membrane. Polymyxins- Not bacteria specific, so usually just topical. Neosporin otherwise this would destroy our cells too.

 

Inhibition of Protein Synthesis- bind to bacterial ribosomes and the bacterial cell can’t make proteins. Aminoglycosides- block proofreading allow the bacteria to make misshaped membrane proteins. Examples include streptomycin and kanamycin.  Tetracyclines- Block tRNA binding to ribosome and inhibits protein synthesis.

 

So in review, antibiotics target vital structures or vital functions of bacterial cells in order to disarm them. These include inhibiting the production of important molecules or pathways or compromising structures like disrupting the cell membrane in order to kill the bacteria and treat the patient.

 

We love you guys! Go out and be your best self today! And as always, Happy Nursing!