Antibacterial Agents I Flashcards
Selective toxicity definition
ability of an antimicrobial agent to target only pathogens and not normal body cells
Typical gram-positive cocci
Streptococci (pneumonia, pyogenes), Staphyloccoci (aureaus: MRSA), Enterococci (faecium)
Typical gram-negative cocci
Neisseria (meningitidis, gonorrheae)
Typical gram-negative rods
E. Coli, Pseudomonas aeruginose
Typical anaerobic gram-positive rods
Clostridia (difficile, tetani, botulinum)
Typical anearobic gram-negative rods
Bacteriodes fragilis
Typical atypical bacteria
Chlamydia, Mycoplasma, Rickettsia
Examples of selective toxicity (5)
- folate metabolism: intracell (bacteria) vs. absorb (mammal) 2. protein synthesis: different ribosomes 3. DNA synthesis: gyrase (bacteria) vs. topoisomerase (mammal) 4. cell wall: no peptidoglycan in eukaryotes 5. ergosterol (fungal membrane) vs. cholesterol (mammal)
Narrrow spectrum antibiotic definition
treats gram-positive or gram-negative bacteria
Extended spectrum antibiotic definition
treats gram-positive and gram-negative bacteria
Broad spectrum antibiotic definition
treats gram-positive and gram-negative bacteria and atypical organisms
Narrrow spectrum antibiotic examples (3)
- aminoglycosides 2. vancomyocin 3. penicillin
Extended spectrum antibiotic examples (3)
- cephalosporins 2. fluoroquinoloes (cip, levo) 3. carbapenems
Braod spectrum antibiotic examples (4)
- macrolides 2. sulfonamides 3. tetracyclines 4. fluoroquinoloes (moxi, gemi)
Natural (intrinsic) resistance definition and example
microbe lacks target for drug action; e.g. fungal cell walls do not contain peptidoglycan