normal resident microbes in our bodies interact with us as
- commensals
- mutualists
resident biota is absent from the
heart
virulence factors include
- toxins
- enzymes
- capsules
the ____ is the time that lapses between an encounter with a pathogen and the first symptoms
period of incubation
a short period early in a disease that may manifest with general malaise and achiness is the
prodrome
a ____ is a passive animal transporter of pathogens
mechanical vector
a positive antibody test for HIV would be a ____ of infection
sign
a seasonal outbreak of influenza would be an example of what type of outbreak?
propagated
define virulence factors
- structures/capabilities that allow a pathogen to cause infection in a host.
- from a microbe’s perspective, they are adaptions it uses to invade and establish itself in a host.
selective toxicity
- kill or inhibit the actions or synthesis of molecules in microorganisms but not vertebrate cells
- drugs w excellent selective toxicity block the synthesis of the bacterial cell walls (penicillins)
goal of antimicrobial chemotherAPY
-easy to administer
-toxic to infectious agent
-nontoxic to the host
LOOK UP THE REST
therapeutic index
the ratio of the dose of the drug that is toxic to humans compared to its minimum effective (therapeutic) dose
Minimum inhibitory concentration (MIC)
- the smallest concentration (highest dilution) of drug that visibly inhibits growth
- useful in determining the smallest effective dosage of a drug and in providing a comparative index against other antimicrobials
goal of antimicrobial chemotherapy
-easy to administer
-toxic to infectious agent
-nontoxic to the host
LOOK UP THE REST
4 main categories of antifungal agents
1) macrolide polyenes
2) azoles
3) echinocandins
4) nucleotide cytosine analog
4 generations of fluoroquinolone
- nalidixic acid (1st generation, rarely used anymore)
- ciprofloxacin, ofloxacin (2nd generation)
- levofloxacin (3rd generation, used against gram-positive organisms)
- trovafloxacin (4th generation, effective against anaerobic organisms)
is a high or low index preferable?
The drug with the highest therapeutic index has the widest margin of safety.
TI= 1.1 is a risky choice
TI= 10 is a safer choice
is a high or low index preferable?
The drug with the highest therapeutic index has the widest margin of safety.
TI= 1.1 is a risky choice
TI= 10 is a safer choice
nosocomial infection/ healthcare-associated infection
infectious diseases acquired or develop during a hospital or health care facility
prevalence
- total # of existing cases with respect to the entire population.
- thought of as a “snap shot”
- reported as the % of the population having a particular disease at any given time .
incidence
- # of NEW cases over certain time period.
- also called the “case” or “morbidity, rate”
- indicated both the rate and risk of infection
what are the 5 major targets of antimicrobial agents?
1) inhibition of cell wall synthesis
2) inhibition of nucleic acid (DNA and RNA) structure & function
3) inhibition of protein synthesis
4) interference with cytoplasmic membrane structure or function
5) inhibition of folic acid synthesis
