Microbiology Exam III - Medical micro QUESTIONS AND
ANSWERS 100% ACCURATE 2025.
Peptidoglycan - ✅✅penicillin targets what
Highest dosage tolerated by patient per the minimum dosage needed to kill microbe -
✅✅therapeutic ratio
Therapeutic ratio - ✅✅effectiveness/quality of an antibiotic is determined by it's
______
High selective toxicity - ✅✅to kill/inhibit microbial cells without damaging host tissues,
antibiotics must have ________
Antibiotics - ✅✅inhibit the growth of other microorganisms
Bacteria, fungi - ✅✅antibiotics are naturally produced by what microorganisms?
Selective toxicity
Side effects (toxicity, allergy, disrupt normal flora)
Solubility
Bacterial resistance to antibiotics
Mode of action/spectrum of inhibition - ✅✅5 factors that affect the therapeutic ratio
More harmful to us - ✅✅less selective drugs will likely be
Systemic fungal infection - ✅✅in what instance might it be necessary to use a low
therapeutic ratio?
Mode of action - ✅✅term meaning "where does the antibiotic target"
Narrow spectrum - ✅✅If you know the exact infection you're fighting, what spectrum
of inhibition would you use?
Broad spectrum - ✅✅effective against several groups of organisms (gram positives
and gram negatives)
Peptidoglycan synthesis - ✅✅What area of the bacterial cell do beta/non-beta
lactams inhibit?
, Gram positive bacteria because they have a thicker peptidoglycan layer and no LPS
layer - ✅✅What are beta/non beta lactams most effective against/why?
Amoxicillin (not good for penR), cephalosporins (rocephin, keflex) - ✅✅Some beta
lactams are broad spectrum. Which?
Sterols in membrane - ✅✅Antibacterials and antifungals interfere and destabilize
what?
Inhibits bacterial DNA synthesis, broad spectrum - ✅✅What does ciproflaxin do?
Spectrum of inhibition?
Inhibits bacterial RNA synthesis (initiation of transcription), broad spectrum - ✅✅What
does rifampin do? Spectrum of inhibition?
Dermatophytic infections, interferes with cell membrane stability - ✅✅Nystatin
(mycostatin) treats what? How?
Low therapeutic ratio, treats systemic infections - ✅✅Amphotericin B also treats
dermatophytic infections in, but how is it different than nystatin? What else does it treat?
gram negative bacteria, neosporin - ✅✅What would polymyxin be used for treating?
Where might we find this ingredient?
Streptococcus pneumoniae, Clostridium tetani, Neisseria meningitidis, Mycobacterium
tuberculosis (outside U.S.), Borrelia burgdorferi (ONLY for dogs) - ✅✅Name the
infection-causing bacteria that have available vaccines
Sulfonamides (sulfa drugs) - ✅✅What drugs mimic enzymes in metabolic pathways?
Superinfection. Drugs that inhibit bacterial protein synthesis - ✅✅Infection caused by
antibiotics? Which category are these usually a complication of (more specific than
"broad spec")?
Streptomycin, gentamycin. Inhibit protein synthesis. Tuberculosis. - ✅✅What are 2
types of aminoglycosides? How do they work? What might they be used for?
Chloramphenicol - ✅✅Protein synthesis inhibitor that crossed BBB?
Base analog of thymidine. Targets DNA replication. - ✅✅How does AZT work?
Ciprofloxacin - ✅✅Inhibits bacterial DNA synthesis?
ANSWERS 100% ACCURATE 2025.
Peptidoglycan - ✅✅penicillin targets what
Highest dosage tolerated by patient per the minimum dosage needed to kill microbe -
✅✅therapeutic ratio
Therapeutic ratio - ✅✅effectiveness/quality of an antibiotic is determined by it's
______
High selective toxicity - ✅✅to kill/inhibit microbial cells without damaging host tissues,
antibiotics must have ________
Antibiotics - ✅✅inhibit the growth of other microorganisms
Bacteria, fungi - ✅✅antibiotics are naturally produced by what microorganisms?
Selective toxicity
Side effects (toxicity, allergy, disrupt normal flora)
Solubility
Bacterial resistance to antibiotics
Mode of action/spectrum of inhibition - ✅✅5 factors that affect the therapeutic ratio
More harmful to us - ✅✅less selective drugs will likely be
Systemic fungal infection - ✅✅in what instance might it be necessary to use a low
therapeutic ratio?
Mode of action - ✅✅term meaning "where does the antibiotic target"
Narrow spectrum - ✅✅If you know the exact infection you're fighting, what spectrum
of inhibition would you use?
Broad spectrum - ✅✅effective against several groups of organisms (gram positives
and gram negatives)
Peptidoglycan synthesis - ✅✅What area of the bacterial cell do beta/non-beta
lactams inhibit?
, Gram positive bacteria because they have a thicker peptidoglycan layer and no LPS
layer - ✅✅What are beta/non beta lactams most effective against/why?
Amoxicillin (not good for penR), cephalosporins (rocephin, keflex) - ✅✅Some beta
lactams are broad spectrum. Which?
Sterols in membrane - ✅✅Antibacterials and antifungals interfere and destabilize
what?
Inhibits bacterial DNA synthesis, broad spectrum - ✅✅What does ciproflaxin do?
Spectrum of inhibition?
Inhibits bacterial RNA synthesis (initiation of transcription), broad spectrum - ✅✅What
does rifampin do? Spectrum of inhibition?
Dermatophytic infections, interferes with cell membrane stability - ✅✅Nystatin
(mycostatin) treats what? How?
Low therapeutic ratio, treats systemic infections - ✅✅Amphotericin B also treats
dermatophytic infections in, but how is it different than nystatin? What else does it treat?
gram negative bacteria, neosporin - ✅✅What would polymyxin be used for treating?
Where might we find this ingredient?
Streptococcus pneumoniae, Clostridium tetani, Neisseria meningitidis, Mycobacterium
tuberculosis (outside U.S.), Borrelia burgdorferi (ONLY for dogs) - ✅✅Name the
infection-causing bacteria that have available vaccines
Sulfonamides (sulfa drugs) - ✅✅What drugs mimic enzymes in metabolic pathways?
Superinfection. Drugs that inhibit bacterial protein synthesis - ✅✅Infection caused by
antibiotics? Which category are these usually a complication of (more specific than
"broad spec")?
Streptomycin, gentamycin. Inhibit protein synthesis. Tuberculosis. - ✅✅What are 2
types of aminoglycosides? How do they work? What might they be used for?
Chloramphenicol - ✅✅Protein synthesis inhibitor that crossed BBB?
Base analog of thymidine. Targets DNA replication. - ✅✅How does AZT work?
Ciprofloxacin - ✅✅Inhibits bacterial DNA synthesis?
