PORTAGE LEARNING: MICROBIOLOGY MODULE 5, PORTAGE
MICROBIOLOGY BIOD171 EXAM 5, PORTAGE MICROBIOLOGY
EXAM #5 | QUESTIONS AND ANSWERS | LATEST EXAM UPDATE
Define the concept of universal precautions. - CORRECT ANSWER -
Universal precautions means any and all samples, whether known or unknown,
are to be treated as potentially hazardous (or pathogenic) materials.
What would a researcher be certain to note while analyzing a microbial sample?
- CORRECT ANSWER - 1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
4. The presence of any chemical reactions
5. Changes in color localized to the organism or the surrounding media
6. Capture (or draw) images of any of the characteristics described above
Which non-selective yet differential agar plate should be used if a Streptococcus
sample is suspected? - CORRECT ANSWER - A BAP (blood agar plate)
would be the quickest way to identify and classify a potential streptococcus
microbe based on its hemolytic properties.
What disease can result if a patient with streptococcal pharyngitis goes
untreated? - CORRECT ANSWER - Rheumatic fever occurs in approximately
3% of untreated cases of streptococcal pharyngitis, presenting approximately 2-3
weeks post-infection.
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing
what disease? - CORRECT ANSWER - All of the above foreign microbes are
capable of causing septicemia, also known as blood poisoning.
,What is a facultative anaerobe? - CORRECT ANSWER - A facultative
anaerobe is capable of growth under both aerobic (with oxygen) and anaerobic
(in the absence of oxygen) condition.
How can Staphylococcus be differentially tested? - CORRECT ANSWER -
Staphylococcus species are capable of growth in the presence of bile salts.
A bacterial swab is taken from a patient with impetigo and streaked across an
MSA plate. Following incubation at 37C, what will be the color of the agar? -
CORRECT ANSWER - The causative agent of impetigo is staph aureus, a
Gram-positive bacterium capable of fermenting mannitol. Fermentation will
lower the pH of the agar and change the dye color from red to yellow.
If a patient were suspected to have tuberculosis (TB), which differential stain
would you select and why? - CORRECT ANSWER - To stain for TB, one
would utilize an acid-fast stain to best visual the foreign microbe. As a
mycobacterium tuberculosis would stain poorly (indeterminate) using the Gram
stain.
According to the module, which mycobacterium infection will be treated free of
charge by the World Health Organization (WHO)? - CORRECT ANSWER -
Leprosy is completely curable using a multiple-drug therapy regimen consisting
of various combinations of the drugs dapsone, rifampin and clofazimine—all of
which is given free of charge.
What are the three main conditions caused by the botulism toxin? - CORRECT
ANSWER - Foodborne, infant and wound. Foodborne botulism is often the
result of improperly canned, contaminated, low-acidic foods such as green
beans, corn and beats. Infant botulism occurs when children, usually under the
age of 6 months consume foods containing the bacteria. A potential source of
infant botulism is honey (which is why pediatricians recommend avoiding
feeding honey to infants) but can also be found in common places such as soil.
Wound botulism occurs when C. botulinum bacteria colonize a deep wound,
often a puncture such as those who inject street drugs such as heroine. As
,contaminated needles are injected through the skin, spores enter the body and,
in the absence of oxygen, release the toxin.
Why are infants (< 6 months) more susceptible to botulism? - CORRECT
ANSWER - Due to infants still maturing intestinal tract and lack of an adult
microbiota, the bacteria are able to colonize and produce the associated toxin. In
adults, only the direct ingestion of the pre-formed toxin causes disease—
ingestion of C. botulinum or the associated spores do not cause illness as a
mature intestinal microbiota sufficiently prevents bacterial germination and
growth.
What is the mechanism of action of the toxin produced by clostridium tentani
(tetanus)? - CORRECT ANSWER - The toxin acts on inhibitory neurons
causing systemic muscle stiffness and spasms. Muscle stiffness can be observed
in the jaw (lock-jaw) or spread systemically (if left untreated) to muscles relating
to respiratory function.
What Gram-negative bacterium might you come into contact with in a
unsanitary hot tub? - CORRECT ANSWER - Legionella is often associated
with unclean water systems such as hot tubs, hot water tanks and AC units.
Notably, legionella can only be transmitted through water droplets small enough
to be inhaled.
What are the three forms of plague, and what regions do they affect? -
CORRECT ANSWER - Bubonic (lymph), pneumonic (lungs) and septicemic
(blood). Bubonic plague is best characterized by painfully swollen lymph nodes.
Pneumonic plague affects the respiratory system (lungs). The most rare of all
three plagues, septicemic plague targets the blood system and, if left untreated,
will develop into a life-threatening illness as the blood-borne bacteria can infect
all major organs.
According to the module, which STD might be best identified via dark-field
microscopy? - CORRECT ANSWER - Syphilis. The causative agent,
treponema pallidum, is a thin spirochete, making Gram staining (and
, visualization) difficult. Treponema is therefore most often best identified via
dark-field microscopy.
Streptococcal Pharyngitis (Strep Throat) - CORRECT ANSWER -
Streptococcus
Gram-positive, round bacterium that tends to link to other bacteria in chain-like
structures
rheumatic fever - CORRECT ANSWER - When streptococcal pharyngitis is
left untreated (3% of cases). Gram-positive
Streptococcal septicemia (Blood poisoning) - CORRECT ANSWER - Group B
Streptococcus infection
Gram-positive
Folliculitis (Inflammation of the hair follicle) - CORRECT ANSWER - Staph
aureus
Gram-positive
Can also manifest other places on the skin
Scalded skin syndrome - CORRECT ANSWER - -Staph aureus
Gram-positive
-lesions over the skin, mostly seen in infants
Impetigo - CORRECT ANSWER - Staph aureus
Gram-positive
Contagious childhood skin disease
Conjunctivitis (pink eye) - CORRECT ANSWER - Staph aureus
MICROBIOLOGY BIOD171 EXAM 5, PORTAGE MICROBIOLOGY
EXAM #5 | QUESTIONS AND ANSWERS | LATEST EXAM UPDATE
Define the concept of universal precautions. - CORRECT ANSWER -
Universal precautions means any and all samples, whether known or unknown,
are to be treated as potentially hazardous (or pathogenic) materials.
What would a researcher be certain to note while analyzing a microbial sample?
- CORRECT ANSWER - 1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
4. The presence of any chemical reactions
5. Changes in color localized to the organism or the surrounding media
6. Capture (or draw) images of any of the characteristics described above
Which non-selective yet differential agar plate should be used if a Streptococcus
sample is suspected? - CORRECT ANSWER - A BAP (blood agar plate)
would be the quickest way to identify and classify a potential streptococcus
microbe based on its hemolytic properties.
What disease can result if a patient with streptococcal pharyngitis goes
untreated? - CORRECT ANSWER - Rheumatic fever occurs in approximately
3% of untreated cases of streptococcal pharyngitis, presenting approximately 2-3
weeks post-infection.
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing
what disease? - CORRECT ANSWER - All of the above foreign microbes are
capable of causing septicemia, also known as blood poisoning.
,What is a facultative anaerobe? - CORRECT ANSWER - A facultative
anaerobe is capable of growth under both aerobic (with oxygen) and anaerobic
(in the absence of oxygen) condition.
How can Staphylococcus be differentially tested? - CORRECT ANSWER -
Staphylococcus species are capable of growth in the presence of bile salts.
A bacterial swab is taken from a patient with impetigo and streaked across an
MSA plate. Following incubation at 37C, what will be the color of the agar? -
CORRECT ANSWER - The causative agent of impetigo is staph aureus, a
Gram-positive bacterium capable of fermenting mannitol. Fermentation will
lower the pH of the agar and change the dye color from red to yellow.
If a patient were suspected to have tuberculosis (TB), which differential stain
would you select and why? - CORRECT ANSWER - To stain for TB, one
would utilize an acid-fast stain to best visual the foreign microbe. As a
mycobacterium tuberculosis would stain poorly (indeterminate) using the Gram
stain.
According to the module, which mycobacterium infection will be treated free of
charge by the World Health Organization (WHO)? - CORRECT ANSWER -
Leprosy is completely curable using a multiple-drug therapy regimen consisting
of various combinations of the drugs dapsone, rifampin and clofazimine—all of
which is given free of charge.
What are the three main conditions caused by the botulism toxin? - CORRECT
ANSWER - Foodborne, infant and wound. Foodborne botulism is often the
result of improperly canned, contaminated, low-acidic foods such as green
beans, corn and beats. Infant botulism occurs when children, usually under the
age of 6 months consume foods containing the bacteria. A potential source of
infant botulism is honey (which is why pediatricians recommend avoiding
feeding honey to infants) but can also be found in common places such as soil.
Wound botulism occurs when C. botulinum bacteria colonize a deep wound,
often a puncture such as those who inject street drugs such as heroine. As
,contaminated needles are injected through the skin, spores enter the body and,
in the absence of oxygen, release the toxin.
Why are infants (< 6 months) more susceptible to botulism? - CORRECT
ANSWER - Due to infants still maturing intestinal tract and lack of an adult
microbiota, the bacteria are able to colonize and produce the associated toxin. In
adults, only the direct ingestion of the pre-formed toxin causes disease—
ingestion of C. botulinum or the associated spores do not cause illness as a
mature intestinal microbiota sufficiently prevents bacterial germination and
growth.
What is the mechanism of action of the toxin produced by clostridium tentani
(tetanus)? - CORRECT ANSWER - The toxin acts on inhibitory neurons
causing systemic muscle stiffness and spasms. Muscle stiffness can be observed
in the jaw (lock-jaw) or spread systemically (if left untreated) to muscles relating
to respiratory function.
What Gram-negative bacterium might you come into contact with in a
unsanitary hot tub? - CORRECT ANSWER - Legionella is often associated
with unclean water systems such as hot tubs, hot water tanks and AC units.
Notably, legionella can only be transmitted through water droplets small enough
to be inhaled.
What are the three forms of plague, and what regions do they affect? -
CORRECT ANSWER - Bubonic (lymph), pneumonic (lungs) and septicemic
(blood). Bubonic plague is best characterized by painfully swollen lymph nodes.
Pneumonic plague affects the respiratory system (lungs). The most rare of all
three plagues, septicemic plague targets the blood system and, if left untreated,
will develop into a life-threatening illness as the blood-borne bacteria can infect
all major organs.
According to the module, which STD might be best identified via dark-field
microscopy? - CORRECT ANSWER - Syphilis. The causative agent,
treponema pallidum, is a thin spirochete, making Gram staining (and
, visualization) difficult. Treponema is therefore most often best identified via
dark-field microscopy.
Streptococcal Pharyngitis (Strep Throat) - CORRECT ANSWER -
Streptococcus
Gram-positive, round bacterium that tends to link to other bacteria in chain-like
structures
rheumatic fever - CORRECT ANSWER - When streptococcal pharyngitis is
left untreated (3% of cases). Gram-positive
Streptococcal septicemia (Blood poisoning) - CORRECT ANSWER - Group B
Streptococcus infection
Gram-positive
Folliculitis (Inflammation of the hair follicle) - CORRECT ANSWER - Staph
aureus
Gram-positive
Can also manifest other places on the skin
Scalded skin syndrome - CORRECT ANSWER - -Staph aureus
Gram-positive
-lesions over the skin, mostly seen in infants
Impetigo - CORRECT ANSWER - Staph aureus
Gram-positive
Contagious childhood skin disease
Conjunctivitis (pink eye) - CORRECT ANSWER - Staph aureus
