VBS 2032 EXAM #3 QUESTIONS AND
ANSWERS GRADED A+
microbial intoxication - answerthe toxin produced by a bacteria is ingested (rather than
the bacteria itself)
microbial infection - answerthe bacteria multiplies in the body
4 phases of infectious disease - answer1. incubation period
2. prodromal period (feel like something is off)
3. period of illness (symptomatic)
4. convalescent period (non-diseased or disability/death)
virulence factors that help a pathogen spread through the body, evade the host immune
defenses, or cause damage to the host - answerattachment
multiplication
invasion or spread
evasion of host defenses
damage to host tissues
asymptomatic carrier - answersomeone who is a carrier of a pathogen but doesnt show
symptoms, yet can still infect others with the pathogen
ex. typhoid mary
latent infection - answerinactive infection - not eliminated from the body but it is not
actively replicating
may become activated and cause disease
infection is not spread
ex. herpes
fomite - answerobjects or materials which are likely to carry infection - like clothes,
utensils, and furniture
what types of microorganisms are transmitted directly - answersmallpox, common cold,
measles
Koch's postulates - answera sequence of experimental steps for directly relating a
specific microbe to a specific disease
what are examples of when koch's postulates can not be satisfied - answerwhen the
organism cannot be cultured
, animal host
when an infection is caused by more than one organism
healthy subject carrying organisms
How did Zimbler et al. determine that a mutated form of pla increased the virulence of Y.
pestis? - answerin more modern strains, there was a gene called pla - through the years
as the pla gene mutated (and had a single nucleotide difference) it became even more
virulent
mice experiment (limited infection --> pneumonic plague --> disseminated infection (in
blood stream))
what virulence factor allows the pathogen to live inside of fleas and how does it
influence transmission - answerbacteria have a gene that promotes transmission
through flea bites (YMT)
allows bacteria to spread very rapidly by allowing it to live in fleas, which infect rats, and
then infect people
direct transmission - answerwithin a close proximity to a person
- sneeze or cough
- handshake
- sexual contact
indirect transmission - answercan travel longer distances
- airborne
- fomites
- food/water
- vector
biological vector - answercarry pathogens that can multiply within their body and be
delivered to new hosts (biting)
mosquitos with malaria, ticks
mechanical vector - answercan pick up infectious agents on the outside of their bodies
and transmit them through physical contact (just carriers, not in their body)
flies, cockroaches
features that maintain the sterility of a healthy urinary tract - answerflushing action of
urine
low pH
urine composition
mucous
inhibitory peptides and antibodies
anatomy
peristalsis
ANSWERS GRADED A+
microbial intoxication - answerthe toxin produced by a bacteria is ingested (rather than
the bacteria itself)
microbial infection - answerthe bacteria multiplies in the body
4 phases of infectious disease - answer1. incubation period
2. prodromal period (feel like something is off)
3. period of illness (symptomatic)
4. convalescent period (non-diseased or disability/death)
virulence factors that help a pathogen spread through the body, evade the host immune
defenses, or cause damage to the host - answerattachment
multiplication
invasion or spread
evasion of host defenses
damage to host tissues
asymptomatic carrier - answersomeone who is a carrier of a pathogen but doesnt show
symptoms, yet can still infect others with the pathogen
ex. typhoid mary
latent infection - answerinactive infection - not eliminated from the body but it is not
actively replicating
may become activated and cause disease
infection is not spread
ex. herpes
fomite - answerobjects or materials which are likely to carry infection - like clothes,
utensils, and furniture
what types of microorganisms are transmitted directly - answersmallpox, common cold,
measles
Koch's postulates - answera sequence of experimental steps for directly relating a
specific microbe to a specific disease
what are examples of when koch's postulates can not be satisfied - answerwhen the
organism cannot be cultured
, animal host
when an infection is caused by more than one organism
healthy subject carrying organisms
How did Zimbler et al. determine that a mutated form of pla increased the virulence of Y.
pestis? - answerin more modern strains, there was a gene called pla - through the years
as the pla gene mutated (and had a single nucleotide difference) it became even more
virulent
mice experiment (limited infection --> pneumonic plague --> disseminated infection (in
blood stream))
what virulence factor allows the pathogen to live inside of fleas and how does it
influence transmission - answerbacteria have a gene that promotes transmission
through flea bites (YMT)
allows bacteria to spread very rapidly by allowing it to live in fleas, which infect rats, and
then infect people
direct transmission - answerwithin a close proximity to a person
- sneeze or cough
- handshake
- sexual contact
indirect transmission - answercan travel longer distances
- airborne
- fomites
- food/water
- vector
biological vector - answercarry pathogens that can multiply within their body and be
delivered to new hosts (biting)
mosquitos with malaria, ticks
mechanical vector - answercan pick up infectious agents on the outside of their bodies
and transmit them through physical contact (just carriers, not in their body)
flies, cockroaches
features that maintain the sterility of a healthy urinary tract - answerflushing action of
urine
low pH
urine composition
mucous
inhibitory peptides and antibodies
anatomy
peristalsis
