Portage Microbiology Exam #5
Universal precautions means any and all samples, whether known or unknown, are to be treated as
potentially hazardous (or pathogenic) materials
Define the concept of universal precautions (short answer)
Need to note:
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
List at lease 3 observations a researcher would be sure to note while assessing and unknown microbial
sample (short answer)
You must determine motility before determining Gram status. Motility requires a wet mount, while
gram staining requires heat fixing the sample. If one were to begin with the gram stain, the heat fixation
process would kill the organism, making any observations regarding motility impossible. The correct
approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the
same liquid culture can be heat fixed and gram stained.
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? (short answer)
, A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen)
conditions
A facultative anaerobe is a microorganism capable of growth under what conditions? (short answer)
False. The Lancefield groups are used to subdivide beta-hemolytic strep
True or False: The Lancefield groups are used to subdivide antigenic groups of alpha-hemolytic
Streptococcus
B. Carbohydrate composition of antigens
The distinctions for Lancefield subgroups lie in its: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above
Beta: strep. Pharyngitis
Rheumatic fever displays _____ hemolytic activity and occurs when _____ if left untreated
False. Staphylococcus in only found (non-symptomatic) in ~30% of the human population
True or False: Under most circumstances, staphylococcus can be found in ~80% of human population
where it remains non-symptomatic
Universal precautions means any and all samples, whether known or unknown, are to be treated as
potentially hazardous (or pathogenic) materials
Define the concept of universal precautions (short answer)
Need to note:
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
List at lease 3 observations a researcher would be sure to note while assessing and unknown microbial
sample (short answer)
You must determine motility before determining Gram status. Motility requires a wet mount, while
gram staining requires heat fixing the sample. If one were to begin with the gram stain, the heat fixation
process would kill the organism, making any observations regarding motility impossible. The correct
approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the
same liquid culture can be heat fixed and gram stained.
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? (short answer)
, A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen)
conditions
A facultative anaerobe is a microorganism capable of growth under what conditions? (short answer)
False. The Lancefield groups are used to subdivide beta-hemolytic strep
True or False: The Lancefield groups are used to subdivide antigenic groups of alpha-hemolytic
Streptococcus
B. Carbohydrate composition of antigens
The distinctions for Lancefield subgroups lie in its: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above
Beta: strep. Pharyngitis
Rheumatic fever displays _____ hemolytic activity and occurs when _____ if left untreated
False. Staphylococcus in only found (non-symptomatic) in ~30% of the human population
True or False: Under most circumstances, staphylococcus can be found in ~80% of human population
where it remains non-symptomatic
