MDSC 515 PRACTICE EXAM TEST 2025/2026 QUESTIONS
AND SOLUTIONS GRADED A+ TIP
✔✔genomic islands - ✔✔-bacterial genome: core genome and flexible gene pool
-flexible: bacteriophages, transposons, plasmids, genomic islands
-pathogenicity islands - encodes virulence factors/determinants
✔✔toxins as therapeutics - ✔✔-most are experimental
-most commonly used is botox
-most are preventative
✔✔diagnostic uses for bacterial virulence factors - ✔✔cell membrane or capsule:
-gram stain
-serology: past infection, can be used for vaccine response or surveillance
-identifying bacteria I diagnostic laboratory
-detection of toxin antigen or gene to determine if a virulent form of a microorganism is
present
✔✔ideal antimicrobial - ✔✔-selective - kills the pathogen, minimal toxicity to the host
-can be given orally or intravenously
-complementary to host defences
-extensive tissue distribution
-chemically stable
-remains active in presence of organic compounds
-low levels of resistance
-minimal drug-drug interactions
✔✔pharmacokinetics - ✔✔-action of the body on the administered drug for absorption,
distribution, metabolism and excretion to define systemic exposure - what the body
does to the drug
✔✔pharmacodynamics - ✔✔-study of biochemical, cellular and physiological effects of
drugs and their mechanisms of action -what the drug does to the body and pathogens
✔✔absorption of drugs - ✔✔-route of administration
-how much of the drug is absorbed
-bioavailability - how much of the oral drug is absorbed into the bloodstream
✔✔distribution of drugs - ✔✔-is the antimicrobial able to reach the site of infection
-drug concentrations are most often measured in blood/serum
-often assume that concentrations of drugs in the blood will reflect concentrations at the
tissues or site of infection
✔✔bacterial meningitis - ✔✔-infection that causes the inflammation of the meninges
, -need antibiotics to cross the blood-brain barrier and blood-CSF barrier to achieve
adequate CSF concentrations
✔✔osteomyelitis - ✔✔-infection of the bone
-must select antibiotic regime that provides good bone penetration
-bone vascularization is relatively poor - this changes with age
✔✔drug metabolism - ✔✔-how does our body break down the drug
-metabolism can be affected by: genetics, age and comorbidities, organ dysfunction,
drug/food interactions
-some drugs have active metabolites
✔✔drug elimination - ✔✔-how does our body get rid of the drug
-through urine or faces
✔✔therapeutic drug monitoring - ✔✔-done for those drugs with adverse side effects
-most drugs have a narrow therapeutic window
-target blood concentration levels that have been studied as surrogate markers for this
therapeutic window
✔✔bactericidal - ✔✔-"kills"
->3-log kill within 24 hour period
-preferred for: severe/serious infections, immunocompromised patients and if the site of
infection is hard to reach
✔✔bacteriostatic - ✔✔-prevents growth
-<3-log kill within 24 hour period
✔✔Concentration-dependent vs time-dependent - ✔✔-MIC = minimum inhibitory
concentration
-time dependent - time spent above MIC
-concentration-dependent = ratio of peak:MIC
✔✔post antibiotic effect - ✔✔-phenomenon that causes a delay in microorganism
recovery after the antibiotic is no longer present
-exact mechanism is unknown - persistence of antibiotic t site or still present despite
unmeasurable amounts of blood
-exact duration depends on organism and drug
-observed with ahminoglycosides and fluoroquinolones
-allows for less frequent administration of the drug
✔✔synergy - ✔✔-if the affect of two antibiotics is greater than 1 alone
✔✔beta-lactams - ✔✔-inhibits cell wall synthesis
-binds penicillin binding protein enzymes (PBPs)
AND SOLUTIONS GRADED A+ TIP
✔✔genomic islands - ✔✔-bacterial genome: core genome and flexible gene pool
-flexible: bacteriophages, transposons, plasmids, genomic islands
-pathogenicity islands - encodes virulence factors/determinants
✔✔toxins as therapeutics - ✔✔-most are experimental
-most commonly used is botox
-most are preventative
✔✔diagnostic uses for bacterial virulence factors - ✔✔cell membrane or capsule:
-gram stain
-serology: past infection, can be used for vaccine response or surveillance
-identifying bacteria I diagnostic laboratory
-detection of toxin antigen or gene to determine if a virulent form of a microorganism is
present
✔✔ideal antimicrobial - ✔✔-selective - kills the pathogen, minimal toxicity to the host
-can be given orally or intravenously
-complementary to host defences
-extensive tissue distribution
-chemically stable
-remains active in presence of organic compounds
-low levels of resistance
-minimal drug-drug interactions
✔✔pharmacokinetics - ✔✔-action of the body on the administered drug for absorption,
distribution, metabolism and excretion to define systemic exposure - what the body
does to the drug
✔✔pharmacodynamics - ✔✔-study of biochemical, cellular and physiological effects of
drugs and their mechanisms of action -what the drug does to the body and pathogens
✔✔absorption of drugs - ✔✔-route of administration
-how much of the drug is absorbed
-bioavailability - how much of the oral drug is absorbed into the bloodstream
✔✔distribution of drugs - ✔✔-is the antimicrobial able to reach the site of infection
-drug concentrations are most often measured in blood/serum
-often assume that concentrations of drugs in the blood will reflect concentrations at the
tissues or site of infection
✔✔bacterial meningitis - ✔✔-infection that causes the inflammation of the meninges
, -need antibiotics to cross the blood-brain barrier and blood-CSF barrier to achieve
adequate CSF concentrations
✔✔osteomyelitis - ✔✔-infection of the bone
-must select antibiotic regime that provides good bone penetration
-bone vascularization is relatively poor - this changes with age
✔✔drug metabolism - ✔✔-how does our body break down the drug
-metabolism can be affected by: genetics, age and comorbidities, organ dysfunction,
drug/food interactions
-some drugs have active metabolites
✔✔drug elimination - ✔✔-how does our body get rid of the drug
-through urine or faces
✔✔therapeutic drug monitoring - ✔✔-done for those drugs with adverse side effects
-most drugs have a narrow therapeutic window
-target blood concentration levels that have been studied as surrogate markers for this
therapeutic window
✔✔bactericidal - ✔✔-"kills"
->3-log kill within 24 hour period
-preferred for: severe/serious infections, immunocompromised patients and if the site of
infection is hard to reach
✔✔bacteriostatic - ✔✔-prevents growth
-<3-log kill within 24 hour period
✔✔Concentration-dependent vs time-dependent - ✔✔-MIC = minimum inhibitory
concentration
-time dependent - time spent above MIC
-concentration-dependent = ratio of peak:MIC
✔✔post antibiotic effect - ✔✔-phenomenon that causes a delay in microorganism
recovery after the antibiotic is no longer present
-exact mechanism is unknown - persistence of antibiotic t site or still present despite
unmeasurable amounts of blood
-exact duration depends on organism and drug
-observed with ahminoglycosides and fluoroquinolones
-allows for less frequent administration of the drug
✔✔synergy - ✔✔-if the affect of two antibiotics is greater than 1 alone
✔✔beta-lactams - ✔✔-inhibits cell wall synthesis
-binds penicillin binding protein enzymes (PBPs)
