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PORTAGE LEARNING MICROBIOLOGY MODULE 5 BOID 171
EXAM 5 NEWEST VERSION -2025/2026- 100+ QUESTIONS AND
VERIFIED ANSWERS 100% CORRECT GUARANTEED SUCCESS
What are the three main conditions caused by the botulism toxin?
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?
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.
Which non-selective yet differential agar plate should be used if a Streptococcus
sample is suspected?
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?
, 2
Rheumatic fever occurs in approximately 3% of untreated cases of streptococcal
pharyngitis, presenting approximately 2-3 weeks post-infection.
How can Staphylococcus be differentially tested?
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?
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?
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)?
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.
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing what
disease?
All of the above foreign microbes are capable of causing septicemia, also known
as blood poisoning.
What is a facultative anaerobe?
A facultative anaerobe is capable of growth under both aerobic (with oxygen) and
anaerobic (in the absence of oxygen) condition.
, 3
What is the mechanism of action of the toxin produced by clostridium tentani
(tetanus)?
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?
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?
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?
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)
Streptococcus
Gram-positive, round bacterium that tends to link to other bacteria in chain-like
structures
rheumatic fever
PORTAGE LEARNING MICROBIOLOGY MODULE 5 BOID 171
EXAM 5 NEWEST VERSION -2025/2026- 100+ QUESTIONS AND
VERIFIED ANSWERS 100% CORRECT GUARANTEED SUCCESS
What are the three main conditions caused by the botulism toxin?
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?
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.
Which non-selective yet differential agar plate should be used if a Streptococcus
sample is suspected?
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?
, 2
Rheumatic fever occurs in approximately 3% of untreated cases of streptococcal
pharyngitis, presenting approximately 2-3 weeks post-infection.
How can Staphylococcus be differentially tested?
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?
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?
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)?
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.
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing what
disease?
All of the above foreign microbes are capable of causing septicemia, also known
as blood poisoning.
What is a facultative anaerobe?
A facultative anaerobe is capable of growth under both aerobic (with oxygen) and
anaerobic (in the absence of oxygen) condition.
, 3
What is the mechanism of action of the toxin produced by clostridium tentani
(tetanus)?
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?
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?
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?
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)
Streptococcus
Gram-positive, round bacterium that tends to link to other bacteria in chain-like
structures
rheumatic fever
