Download 1 Micro TA Questions

Week One
TA Review Questions
A 24 year old female presents to your office with burning urination,
urgency and frequency. She is sexually active. Urine cultures show
catalase positive, gram-positive cocci. The organism responsible for this
patient’s symptoms is most likely to be:
A)
B)
C)
D)
E)
Coagulase positive
Hemolytic
Novobiocin resistant
Dnase postive
Yellow pigment producer
A 24 year old female presents to your office with burning urination,
urgency and frequency. She is sexually active. Urine cultures show
catalase positive, gram-positive cocci. The organism responsible for this
patient’s symptoms is most likely to be:
A)
B)
C)
D)
E)
Coagulase positive
Hemolytic
Novobiocin resistant
Dnase postive
Yellow pigment producer
A 24 year old female presents to your office with burning urination,
urgency and frequency. She is sexually active. Urine cultures show
catalase positive, gram-positive cocci. The organism responsible for this
patient’s symptoms is most likely to be:
A)
B)
C)
D)
E)
Coagulase positive
Hemolytic
Novobiocin resistant
Dnase postive
Yellow pigment producer
A 24 year old female presents to your office with burning urination,
urgency and frequency. She is sexually active. Urine cultures show
catalase positive, gram-positive cocci. The organism responsible for this
patient’s symptoms is most likely to be:
A)
B)
C)
D)
E)
Coagulase positive
Hemolytic
Novobiocin resistant
Dnase postive
Yellow pigment producer
A 24 year old female presents to your office with burning urination,
urgency and frequency. She is sexually active. Urine cultures show
catalase positive, gram-positive cocci. The organism responsible for this
patient’s symptoms is most likely to be:
A)
B)
C)
D)
E)
Coagulase positive (S. aureus)
Hemolytic (S. aureus, GAS, GBS)
Novobiocin resistant
Dnase postive (GAS)
Yellow pigment producer (S. aureus)
A 17 year-old girl presents to your office with dark urine and facial
puffiness. She had a minor skin infection several weeks ago that
resolved spontaneously. Microscopic examination of the urine
sediment shows red blood cell casts. The organisms responsible for
this patient’s symptoms would most likely demonstrate:
A)
B)
C)
D)
Catalase positivity
Optochin resistance
Bacitracin sensitivity
Optochin sensitivity
A 17 year-old girl presents to your office with dark urine and facial
puffiness. She had a minor skin infection several weeks ago that
resolved spontaneously. Microscopic examination of the urine
sediment shows red blood cell casts. The organisms responsible for
this patient’s symptoms would most likely demonstrate:
A)
B)
C)
D)
Catalase positivity
Optochin resistance
Bacitracin sensitivity
Optochin sensitivity
A 17 year-old girl presents to your office with dark urine and facial
puffiness. She had a minor skin infection several weeks ago that
resolved spontaneously. Microscopic examination of the urine
sediment shows red blood cell casts. The organisms responsible for
this patient’s symptoms would most likely demonstrate:
A)
B)
C)
D)
Catalase positivity
Optochin resistance
Bacitracin sensitivity
Optochin sensitivity
A 17 year-old girl presents to your office with dark urine and facial
puffiness. She had a minor skin infection several weeks ago that
resolved spontaneously. Microscopic examination of the urine
sediment shows red blood cell casts. The organisms responsible for
this patient’s symptoms would most likely demonstrate:
A)
B)
C)
D)
Catalase positivity (Staph)
Optochin resistance (Strep viridans)
Bacitracin sensitivity
Optochin sensitivity (Strep pneumo)
BONUS QUESTION: What best describes the molecular
mechanism behind the last patient’s complaints?
A)
B)
C)
D)
Molecular mimicry
Immune complex deposition
Elaboration of erythrogenic exotoxin
Inappropriate release of cytokines
BONUS QUESTION: What best describes the molecular
mechanism behind the last patient’s complaints?
A)
B)
C)
D)
Molecular mimicry
Immune complex deposition
Elaboration of erythrogenic exotoxin
Inappropriate release of cytokines
A 17 year-old girl presents to your office with a two day history of
fever and sore joints. Her right knee became sore and swollen and
then improved, but now her left elbow hurts. She had a sore throat
three weeks ago, but never saw a doctor. What molecular
mechanism best describes this patient’s complaints?
A)
B)
C)
D)
Molecular mimicry
Immune complex deposition
Elaboration of erythrogenic exotoxin
Inappropriate release of cytokines
A 17 year-old girl presents to your office with a two day history of
fever and sore joints. Her right knee became sore and swollen and
then improved, but now her left elbow hurts. She had a sore throat
three weeks ago, but never saw a doctor. What molecular
mechanism best describes this patient’s complaints?
A)
B)
C)
D)
Molecular mimicry
Immune complex deposition
Elaboration of erythrogenic exotoxin
Inappropriate release of cytokines
A 17 year-old girl presents to your office with a two day history of
fever and sore joints. Her right knee became sore and swollen and
then improved, but now her left elbow hurts. She had a sore throat
three weeks ago, but never saw a doctor. The organisms responsible
for this patient’s symptoms would most likely demonstrate:
A)
B)
C)
D)
Molecular mimicry
Immune complex deposition (PSGN)
Elaboration of erythrogenic exotoxin (scarlet fever)
Inappropriate release of cytokines (toxic shock syndrome)
Group A Strep demonstrate significant resistance to
phagoctytic killing when placed in fresh human blood.
This resistance can be most effectively overcome by
adding antibodies to which of the following?
A)
B)
C)
D)
E)
Protein M
Stretolysin O
Dnase
Streptokinase
Teichoic acid
Group A Strep demonstrate significant resistance to
phagoctytic killing when placed in fresh human blood.
This resistance can be most effectively overcome by
adding antibodies to which of the following?
A)
B)
C)
D)
E)
Protein M
Stretolysin O
Dnase
Streptokinase
Teichoic acid
Compared to gram-positive bacteria, gram-negative bacteria
have:
a)
Thinner peptidoglycan wall and no outer membrane
b) Thicker peptidoglycan wall and outer membrane
c)
Thinner peptidoglycan wall and outer membrane
d) Thicker membrane and no peptidoglycan wall
e) Thinner membrane and no peptidoglycan wall
Compared to gram-positive bacteria, gram-negative bacteria
have:
a)
Thinner peptidoglycan wall and no outer membrane
b) Thicker peptidoglycan wall and outer membrane
c)
Thinner peptidoglycan wall and outer membrane
d) Thicker membrane and no peptidoglycan wall
e) Thinner membrane and no peptidoglycan wall
Recently, a nursing home has discovered a strain of MRSA among
the residents. By what mechanism does MSSA become MRSA?
a)
Alterations in the beta-lactamase
b) Alteration in the penicillin binding protein
c)
Development of a pump to get the antibiotic out of the cell
d) Amino acid substitution at peptidoglycan binding site
e) Development of enzymes to inactivate drug
f)
Alteration of ribosomal proteins
Recently, a nursing home has discovered a strain of MRSA among
the residents. By what mechanism does MSSA become MRSA?
a)
Alterations in the beta-lactamase
b) Alteration in the penicillin binding protein
c)
Development of a pump to get the antibiotic out of the cell
d) Amino acid substitution at peptidoglycan binding site
e) Development of enzymes to inactivate drug
f)
Alteration of ribosomal proteins
a. Establishes an extracellular
protein matrix called a biofilm,
which protects it from
antibiotics and the host’s
immune system.
2
1
b. Often no bacterial invasion,
but still at risk for multi-system
organ failure.
3
Catalase +
Coagulase -
c. Release endotoxin when
killed, resulting in potent
inflammation.
4
d. Secretes protein A, which
binds to the Fc terminal of IgG
and inhibits complement
fixation and phagocytosis.
e. Has a thick peptidoglycan
layer along with teichoic and
lipoteichoic acids.
5
All of the following may be found in both gram-positive and
gram-negative bacteria EXCEPT:
a)
Peptidoglycan layer
b) Pili
c)
Teichoic acid
d) Cell membrane
e) Capsule
All of the following may be found in both gram-positive and
gram-negative bacteria EXCEPT:
a)
Peptidoglycan layer
b) Pili
c)
Teichoic acid
d) Cell membrane
e) Capsule
Which of the following antibiotic classes DOES NOT work by
inhibiting ribosomal subunits?
a)
Aminoglycosides
b) Tetracyclines
c)
Fluoroquinolones
d) Macrolides
e) None of the above
Which of the following antibiotic classes DOES NOT work by
inhibiting ribosomal subunits?
a)
Aminoglycosides
b) Tetracyclines
c)
Fluoroquinolones
d) Macrolides
e) None of the above
A 6 year old boy comes in to your clinic with
otitis media. How could you confirm the most
likely organism?
a. Quellung reaction
b. ASO titer
c. Ask a TA
d. PCR
e. Serology
A 6 year old boy comes in to your clinic with
otitis media. How could you confirm the most
likely organism?
a. Quellung reaction
b. ASO titer
c. Ask a TA
d. PCR
e. Serology
Which of the following complications of S. aureus infection is
NOT caused by a toxin?
a)
Toxic shock syndrome
b) Impetigo
c)
Scalded skin syndrome
d) Gastroenteritis
e) None of the above
Which of the following complications of S. aureus infection is
NOT caused by a toxin?
a)
Toxic shock syndrome
b) Impetigo
c)
Scalded skin syndrome
d) Gastroenteritis
e) None of the above
A 37-year-old female presents to the emergency room with a fever. Chest xray shows multiple patchy infiltrates in both lungs. Echocardiography and
blood cultures suggest a diagnosis of acute bacterial endocarditis limited
to the tricuspid valve. Which of the following is the most probable
predisposing condition?
A. Congenital heart disease
B. Illicit drug use
C. Rheumatic fever
D. Rheumatoid arthritis
E. Systemic lupus erythematosus
A 37-year-old female presents to the emergency room with a fever. Chest xray shows multiple patchy infiltrates in both lungs. Echocardiography and
blood cultures suggest a diagnosis of acute bacterial endocarditis limited
to the tricuspid valve. Which of the following is the most probable
predisposing condition?
A. Congenital heart disease
B. Illicit drug use
C. Rheumatic fever
D. Rheumatoid arthritis
E. Systemic lupus erythematosus
A 45-year-old male goes to the dentist for a routine cleaning. He
subsequently developed a subacute bacterial endocarditis. Which of the
following is true regarding the most likely causative organism?
A. Catalase Positive
B. Optochin Sensitive
C. M-Protein virulence Factor
D. Part of the normal flora of the oropharynx
E. Also a major cause of pneumonia
A 45-year-old male goes to the dentist for a routine cleaning. He subsequently
developed a subacute bacterial endocarditis. Which of the following is true
regarding the most likely causative organism?
A. Catalase Positive
B. Optochin Sensitive
C. M-Protein virulence Factor
D. Part of the normal flora of the oropharynx
E. Also a major cause of pneumonia
An 8 year old child is brought to the ED because his mother has noticed that
his urine has had an orange color for the past week that has been getting
darker. On physical exam, the child's blood pressure is 160/100 and you
notice some edema of the lower extremities. Labs reveal a creatinine of
4.3 mg/dL (normal 0.6-1.2 mg/dL). You also learn that a few weeks ago,
the child had a fever and sore throat. What is the most appropriate next
step?
a) Throat culture
b) Urine culture
c) ASO titer
d) Empiric treatment with amoxicillin
e) Referral to a kidney transplant surgeon
An 8 year old child is brought to the ED because his mother has noticed that
his urine has had an orange color for the past week that has been getting
darker. On physical exam, the child's blood pressure is 160/100 and you
notice some edema of the lower extremities. Labs reveal a creatinine of
4.3 mg/dL (normal 0.6-1.2 mg/dL). You also learn that a few weeks ago,
the child had a fever and sore throat. What is the most appropriate next
step?
a) Throat culture
b) Urine culture
c) ASO titer
d) Empiric treatment with amoxicillin
e) Referral to a kidney transplant surgeon
One of three blood culture bottles drawn from a patient
with unexplained fevers reveals gram-positive cocci
growing in clusters. Which of the following tests would be
most useful in determining whether this organism is a part
of the normal skin flora?
A. Bacitracin resistance
B. Catalase
C. Coagulase
D. Novobiocin resistance
E. Optochin resistance
One of three blood culture bottles drawn from a patient
with unexplained fevers reveals gram-positive cocci
growing in clusters. Which of the following tests would be
most useful in determining whether this organism is a part
of the normal skin flora?
A. Bacitracin resistance
B. Catalase
C. Coagulase
D. Novobiocin resistance
E. Optochin resistance
In molecular biology research, it is not uncommon to take
advantage of bacteria's ability to take up DNA from the
environment by combining bacteria with purified DNA
and then growing the bacteria to amplify DNA copy
number. This is termed:
a) Transduction
b) Conjugation
c) Incubation
d) Transformation
e) Transposition
In molecular biology research, it is not uncommon to take
advantage of bacteria's ability to take up DNA from the
environment by combining bacteria with purified DNA
and then growing the bacteria to amplify DNA copy
number. This is termed:
a) Transduction
b) Conjugation
c) Incubation
d) Transformation
e) Transposition
Which of the following best characterizes the predominant normal
flora of the skin, which is commonly seen as a blood culture
contaminant?
a)
Gram-positive, alpha hemolytic cocci
b) Gram-positive, beta hemolytic cocci
c)
Gram-positive, gamma hemolytic cocci
d) Gram-positive, catalase-positive, coagulase-positive cocci
e) Gram-positive, catalase-positive, coagulase-negative cocci
Which of the following best characterizes the predominant normal
flora of the skin, which is commonly seen as a blood culture
contaminant?
a)
Gram-positive, alpha hemolytic cocci
b) Gram-positive, beta hemolytic cocci
c)
Gram-positive, gamma hemolytic cocci
d) Gram-positive, catalase-positive, coagulase-positive cocci
e) Gram-positive, catalase-positive, coagulase-negative cocci
A 30 year old man comes into the ER sweating profusely and has
a mild fever. He says that in the last few days he has been very
short of breath, has developed a cough and palpitations, and
has been waking up at night with sweating. The only other
significant piece of information you get from his history is that
he had dental surgery about 6 weeks ago and that he only filled
his prescription for pain medication and not for his antibiotics.
The organism most likely responsible for these symptoms is:
a) Staphylococcus aureus
b) Streptococcus viridans group
c) Streptococcus pyogenes
d) Staphylococcus epidermidis
e) Streptococcus bovis
A 30 year old man comes into the ER sweating profusely and has
a mild fever. He says that in the last few days he has been very
short of breath, has developed a cough and palpitations, and
has been waking up at night with sweating. The only other
significant piece of information you get from his history is that
he had dental surgery about 6 weeks ago and that he only filled
his prescription for pain medication and not for his antibiotics.
The organism most likely responsible for these symptoms is:
a) Staphylococcus aureus
b) Streptococcus viridans group
c) Streptococcus pyogenes
d) Staphylococcus epidermidis
e) Streptococcus bovis
A 2 year old child presents with a fever and a diffuse rash that
resembles an extremely bad sunburn with some unroofed blisters on
the face. You make a diagnosis of Staph Scalded Skin Syndrome.
When you attempt to culture the blisters, nothing grows. The reason
is that:
a)
This syndrome is caused by enterotoxin produced by Staph. aureusand
the organism is not actually in the skin
b) This syndrome is caused by TSST-1 toxin produced by Staph.
epidermidis and the organism is not actually in the skin
c) This syndrome is caused by exfoliative toxin produced by Staph.
aureus and the organism is not actually in the skin
d) An adequate sample was not obtained by culture and should be
repeated, since this syndrome is caused by Staph. aureus invading the
skin
e) Staph. epidermidis does not readily grow on standard media
A 2 year old child presents with a fever and a diffuse rash that
resembles an extremely bad sunburn with some unroofed blisters on
the face. You make a diagnosis of Staph Scalded Skin Syndrome.
When you attempt to culture the blisters, nothing grows. The reason
is that:
a)
This syndrome is caused by enterotoxin produced by Staph. aureusand
the organism is not actually in the skin
b) This syndrome is caused by TSST-1 toxin produced by Staph.
epidermidis and the organism is not actually in the skin
c) This syndrome is caused by exfoliative toxin produced by Staph.
aureus and the organism is not actually in the skin
d) An adequate sample was not obtained by culture and should be
repeated, since this syndrome is caused by Staph. aureus invading the
skin
e) Staph. epidermidis does not readily grow on standard media
threw up a few hours after an office picnic. She has felt fine
since but is going on vacation tomorrow and wants to make
sure she won’t be sick. After you reassure her that her
disease was caused by a pre-formed toxin and that she
should be fine, the woman asks you about the bacteria that
made the toxin. Luckily you haven’t repressed all of your
memories from medical school and so you can tell her that
the bug is a:
a)
b)
c)
d)
e)
Gram positive cocci in chains &coagulase positive
Gram negative cocci in clusters &catalase negative
Gram positive cocci in chains &coagulase negative
Gram positive cocci in clusters &coagulase positive
Gram positive cocci in clusters &coagulase negative
A woman comes into your office to see you because she threw up a few hours
after an office picnic. She has felt fine since but is going on vacation
tomorrow and wants to make sure she won’t be sick. After you reassure her
that her disease was caused by a pre-formed toxin and that she should be
fine, the woman asks you about the bacteria that made the toxin. Luckily you
haven’t repressed all of your memories from medical school and so you can
tell her that the bug is a:
a)
b)
c)
d)
e)
Gram positive cocci in chains &coagulase positive
Gram negative cocci in clusters &catalase negative
Gram positive cocci in chains &coagulase negative
Gram positive cocci in clusters &coagulase positive
Gram positive cocci in clusters &coagulase negative
The age group most susceptible to
Group B Streptococcus infections is:
a)
b)
c)
d)
e)
< 1 mo
1-5 years
12-25 years
>75
Not age related – greatest risk is for IV drug users
The age group most susceptible to
Group B Streptococcus infections is:
a)
b)
c)
d)
e)
< 1 mo
1-5 years
12-25 years
>75
Not age related – greatest risk is for IV drug
users