Targets of Action
Which antimicrobial target involves peptidoglycan?
Cell wall
What happens to bacteria when the cell wall is inhibited?
It bursts (lysis)
If a drug affects both bacterial and human ribosomes, what does that say about its selectivity?
It has low selective toxicity
What does selective toxicity mean?
Harms bacteria more than human cells
What does bactericidal mean?
Kills bacteria
Which target is responsible for protein production?
Ribosomes
What is the result of inhibiting protein synthesis?
Bacteria cannot make proteins
What type of ribosome do human cells have?
80s
Why are cell wall drugs highly selective?
Humans don’t have cell walls
Which type of drug relies on the immune system to fully clear the infection?
Bacteriostatic
Which antimicrobial target is disrupted to cause leakage of cell contents?
Cell Membrane
What happens when DNA replication is blocked?
Bacteria cannot reproduce
What are the subunits of a 70S ribosome?
50S + 30S
Why don’t antibiotics usually affect human ribosomes?
Humans have 80S, bacteria have 70S
If bacterial growth resumes after the drug is removed, which type of drug was most likely used?
Bacteriostatic
Which target involves blocking folic acid production?
Metabolism
What happens when the cell membrane is damaged?
Cell contents leak out
Why would a drug that targets ribosomes be considered bacteriostatic instead of bactericidal?
It stops protein production and growth rather than directly killing the cell
Why are drugs targeting metabolic pathways like folic acid synthesis selectively toxic?
Bacteria make their own folic acid, humans obtain it from diet
Why might a bacteriostatic drug be less effective in immunocompromised patients?
Because it relies on the immune system to clear the infection
Which antimicrobial target would directly stop bacterial replication, and why?
DNA/RNA, because replication requires DNA
Why does blocking folic acid synthesis stop bacterial growth?
They cannot make DNA
An antibiotic binds to the 30S subunit. Which organism is most affected?
Bacteria
Why are drugs targeting metabolism selectively toxic?
Bacteria make their own folic acid; humans don’t
Why might bactericidal drugs be preferred in serious infections?
They kill bacteria directly rather than just stopping growth