BIOD 171 : MODULE 5
Study online at https://quizlet.com/_hntk37
1. Define the concept of universal precautions.: Universal precautions means any and all
samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials.
2. List at least 3 observations a researcher would be sure to note while assessing
an unknown microbial sample.: 1. size and shape
2. gram status
3. any observable motility
3. While observing an unknown sample of limited amounts, a researcher must
determine the following observations: (1) the presence of any motility and (2)
its Gram status using the same sample—the liquid sample cannot be divided.
Which would you determine first and why?: You would need to determine the motility first and
then the Gram status. Motility requires a wet mount and Gram staining requires heat fixing the sample. If you perform
a Gram stain first the heat fixation would kill the organism, making it impossible to observe motility.
4. A facultative anaerobe is a microorganism capable of growth under what
conditions?: It is capable of growth under both anaerobic and aerobic conditions
5. As Streptococcus is catalase negative would it thrive or die in the presence of
peroxides? Why?: It would die. Because it is catalase negative it wouldn't be able to breakdown peroxides.
6. Streptococcus is most often streaked onto:
- Chocolate agar
- EMB agar
- Blood agar
- Spirit Blue agar: Blood agar
Strep is often cultured on Blood agar plates to determine its hemolytic properties, which aids in the classification (and
differentiation) process.
7. True or False. The Lancefield groups are used to subdivide antigenic groups
of gamma-hemolytic Streptococcus.: False
The Lancefield groupings are used to subdivide beta-hemolytic Strep
8. Greater than 90% of all human streptococcal infections belong to:
- Group C
- Group B
- Group A
1/6
, BIOD 171 : MODULE 5
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- Group D: Group A
Group A is the causative agent behind> 90% of all strep infections
9. Rheumatic fever displays ______ hemolytic activity and occurs when _______ is
left untreated.
Beta; Rheumatic fever
Alpha; Strep. Pharyngitis
Beta; Strep. Pharyngitis
Gamma; Strep. Septicemia: Beta; Strep. Pharyngitis
Strep throat (also known as strep. Pharyngitis) can lead to Rheumatic fever if left untreated and displays beta-hemolytic
activity
10. True or False. Under most circumstances, staphylococcus can be found in
~80% of human population where it remains non-symptomatic.: False
Staphylococcus is only found in (symptomatic) -30% of all human populations
11. When a bacterium neither harms nor benefits from the host from which it
obtains nutrients, it is referred to as being _____: Commensal
12. Match the step of infection to its description.
Attachment
Evasion
Entry
Pathogen masks its own antigens
Utilization of a portal to gain access to host tissues
Pathogen finds a specific target: Attachment- pathogen finds a specific target
Evasion- pathogen masks its own antigens
Entry- utilization of a portal to gain access to host tissues
13. Match the following symptoms with their respective diseases:
1. Childhood skin disease near mouth/nose
2/6
Study online at https://quizlet.com/_hntk37
1. Define the concept of universal precautions.: Universal precautions means any and all
samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials.
2. List at least 3 observations a researcher would be sure to note while assessing
an unknown microbial sample.: 1. size and shape
2. gram status
3. any observable motility
3. While observing an unknown sample of limited amounts, a researcher must
determine the following observations: (1) the presence of any motility and (2)
its Gram status using the same sample—the liquid sample cannot be divided.
Which would you determine first and why?: You would need to determine the motility first and
then the Gram status. Motility requires a wet mount and Gram staining requires heat fixing the sample. If you perform
a Gram stain first the heat fixation would kill the organism, making it impossible to observe motility.
4. A facultative anaerobe is a microorganism capable of growth under what
conditions?: It is capable of growth under both anaerobic and aerobic conditions
5. As Streptococcus is catalase negative would it thrive or die in the presence of
peroxides? Why?: It would die. Because it is catalase negative it wouldn't be able to breakdown peroxides.
6. Streptococcus is most often streaked onto:
- Chocolate agar
- EMB agar
- Blood agar
- Spirit Blue agar: Blood agar
Strep is often cultured on Blood agar plates to determine its hemolytic properties, which aids in the classification (and
differentiation) process.
7. True or False. The Lancefield groups are used to subdivide antigenic groups
of gamma-hemolytic Streptococcus.: False
The Lancefield groupings are used to subdivide beta-hemolytic Strep
8. Greater than 90% of all human streptococcal infections belong to:
- Group C
- Group B
- Group A
1/6
, BIOD 171 : MODULE 5
Study online at https://quizlet.com/_hntk37
- Group D: Group A
Group A is the causative agent behind> 90% of all strep infections
9. Rheumatic fever displays ______ hemolytic activity and occurs when _______ is
left untreated.
Beta; Rheumatic fever
Alpha; Strep. Pharyngitis
Beta; Strep. Pharyngitis
Gamma; Strep. Septicemia: Beta; Strep. Pharyngitis
Strep throat (also known as strep. Pharyngitis) can lead to Rheumatic fever if left untreated and displays beta-hemolytic
activity
10. True or False. Under most circumstances, staphylococcus can be found in
~80% of human population where it remains non-symptomatic.: False
Staphylococcus is only found in (symptomatic) -30% of all human populations
11. When a bacterium neither harms nor benefits from the host from which it
obtains nutrients, it is referred to as being _____: Commensal
12. Match the step of infection to its description.
Attachment
Evasion
Entry
Pathogen masks its own antigens
Utilization of a portal to gain access to host tissues
Pathogen finds a specific target: Attachment- pathogen finds a specific target
Evasion- pathogen masks its own antigens
Entry- utilization of a portal to gain access to host tissues
13. Match the following symptoms with their respective diseases:
1. Childhood skin disease near mouth/nose
2/6
