DRAW IT Show where the following antibiotics work: ciprofloxacin, tetracvcline, streptomycin, vancomycin, polymyxin B, sulfanilamide, rifampin, erythromycin.
To review:
Themode of action of given antibiotics in a bacterial cell.
Concept introduction:
The antibiotics can either act as a bacteriostatic (prevent growth of bacteria) or bactericidal (kill bacteria) agents. These drugs with a specific mode of action inhibits the essential biological processes of the target pathogen, including disruption of plasma membrane permeability, inhibition of cell wall, protein and nucleic acid synthesis, and inhibition of essential metabolites synthesis.
Answer to Problem 1R
Correct answer:
ANTIBIOTICS | MODE OF ACTION |
Ciprofloxacin | Inhibition of the nucleic acid replication |
Tetracycline | Inhibition of the protein synthesis |
Streptomycin | Inhibition of the protein synthesis |
Vancomycin | Inhibition of the cell wall synthesis |
Polymyxin B | Injury to the plasma membrane |
Sulfanilamide | Inhibition of the essential metabolite synthesis |
Rifampin | Inhibition of the nucleic acid transcription |
Erythromycin | Inhibition of the protein synthesis |
Explanation of Solution
Diagram:
Explanation:
The mechanism of action of the given antibacterial drugs:
Ciprofloxacin – A broad spectrum of the bactericidal agent inhibits the bacterial enzyme DNA gyrase and blocks DNA synthesis. The DNA gyrase is an essential enzyme which is specifically involved in the introduction of negative supercoiling.
Tetracycline – A broad spectrum of the bacteriostatic agent prevents the attachment of aminoacyl tRNA from binding to bacterial 30S ribosome. By binding to the 30S subunit of bacterial ribosome, the tetracycline blocks the association of aminoacyl tRNA with the acceptor site.
Streptomycin – A broad spectrum of the bactericidal agent by acting on 70S ribosome inhibits the protein synthesis. It binds to the 30S subunit of bacterial ribosome and disrupts the protein synthesis (initiation and elongation step).
Vancomycin – A broad spectrum of the antibacterial agent inhibits the assembly of cell wall of bacteria. The N-acetylmuramic acid (NAG) and N-acetylglucosamine (NAM) monomers are the the building blocks of peptidoglycan cell wall. By binding to NAG and NAM, the vancomycin prevents the action of transpeptidase enzyme which is involved in the cross-linking of peptidoglycan.
Polymyxin B – A broad spectrum of the bactericidal agent with a cationic detergent action disrupts the permeability of the plasma membrane.
Sulfanilamide – A broad spectrum of the bacteriostatic agent acts as a competitive inhibitor of p-aminobenzoic acid (PABA). The sulfanilamide with a similar chemical structure competitively prevents the action of PABA and inhibits the folic acid biosynthesis. This arrests the bacterial growth and ultimately results in the elimination of the bacteria.
Rifampin – A broad spectrum of the bactericidal agent specifically inhibits the function of RNA polymerase in the bacteria. Rifampin forms a stable complex with the enzyme, thereby inhibits its activity in the nucleic acid transcription.
Erythromycin – A broad spectrum of the antibacterial agent inhibits the protein synthesis by binding to the bacterial 50S ribosome. It inhibits the activity of peptidyl transferase and intervenes with the amino acid translocation and protein assembly.
The specific site of action of the given antibacterial agents, namely cell wall synthesis (vancomycin), protein synthesis (tetracycline, streptomycin, erythromycin), essential metabolite synthesis (sulfanilamide), nucleic acid synthesis (ciprofloxacin), nucleic acid transcription (rifampin), and plasma membrane integrity (polymyxin B) is shown.
Want to see more full solutions like this?
Chapter 20 Solutions
Microbiology: An Introduction (13th Edition)
Additional Science Textbook Solutions
Microbiology Fundamentals: A Clinical Approach
Chemistry & Chemical Reactivity
Chemistry: A Molecular Approach (4th Edition)
Cosmic Perspective Fundamentals
Biology: Life on Earth with Physiology (11th Edition)
- Many antibiotics used in modern medicine are compounds made by fungi that inhibit bacterial protein synthesis. Describe the specific effect of the following antimicrobial drugs: (i) Tetracycline (ii) Puromycin (iii) Alpha-Amanitinarrow_forwardIn the zone of Inhibition (mm) of each drug record data as Resistant, Intermediate or Susceptible.arrow_forwardDefine the following terms: Bactericidal Bacteriostatic Antisepsisarrow_forward
- Which among the group would be affected when excessive Zn++ is present in the medium? Provide two (2) corrective actions to resolve this error.arrow_forwardlist 3 different mechanisms of antibacterial drugs. Example: acting on cell wall, cell membrane, etcarrow_forwardIdentify a correct statement about tetracyclines. Multiple Choice They have a narrow antibacterial spectrum. They are bactericidal in nature. They bind irreversibly to bacterial ribosomes to inhibit bacterial protein synthesis. Their widespread use has allowed the emergence of bacterial resistance.arrow_forward
- list 4 families of antimicrobials that belong to the beta-lactam grouparrow_forwardIndicate for each organism if it is susceptible, Intermediate or Resistant. Answer the question 2 and 3.arrow_forwardList all the antibiotics in the above table that work through destroying the bacterial cell wall. (if there are none listed please state that)arrow_forward
- Resistance to antimicrobial agents is more commonly seen in hospital-acquired infections with enteric bacteria than in community-based infections with the same species. Explain why this is so.arrow_forwardCan caffeic acid be used to treat cytomegalovirus CMV? Explain.arrow_forwardList down the 25 different antibiotics and give the mechanism of action.arrow_forward
- Essentials of Pharmacology for Health ProfessionsNursingISBN:9781305441620Author:WOODROWPublisher:Cengage