Lab Question Set 3 Flashcards
What is a selective medium?
4-4: Mannitol Salt Agar
Explain how mannitol salt agar is selective.
4-4: Mannitol Salt Agar
What is a differential medium
4-4: Mannitol Salt Agar
Explain how mannitol salt agar is differential.
4-4: Mannitol Salt Agar
Mannitol salt agar favors organisms capable of tolerating ______________________.
4-4: Mannitol Salt Agar
Mannitol salt agar is used to differentiate pathogenic __________________________________ species, which ferment mannitol, from less pathogenic species that do not.
4-4: Mannitol Salt Agar
The pH indicator in mannitol salt agar is ___________________________.
4-4: Mannitol Salt Agar
Phenol Red
The development of ________________ halos around bacterial growth on this medium is an indication that mannitol has been fermented with the production of ____________________.
4-4: Mannitol Salt Agar
Organisms plated on mannitol salt agar that cannot tolerate the level of salinity in the agar will show what kind of
growth?
4-4: Mannitol Salt Agar
Describe a negative result on mannitol salt agar (2 possibilities).
4-4: Mannitol Salt Agar
If bacteria grow on this agar and produce a pink color, is that a positive or a negative result? What causes the pink color?
4-4: Mannitol Salt Agar
True or false. If an organism grows on mannitol salt agar and produces a pink color, the organism cannot tolerate the sodium chloride concentration (osmotic pressure) in the medium.
4-4: Mannitol Salt Agar
Why are selective and differential media like this one very helpful identifying bacteria?
4-4: Mannitol Salt Agar
Name an organism (genus and species) that gives a positive result on the agar.
4-4: Mannitol Salt Agar
Your lab manual says that the nutrient agar control plate in this experiment, is “a comparison for growth quality.”
4-4: Mannitol Salt Agar
Describe a + result on mannitol salt agar. What did the organism do, in order to produce this result?
4-4: Mannitol Salt Agar
What is hemolysin?
5-25: Blood Agar
What does alpha hemolysis look like on blood agar? What do bacteria do to RBC’s to produce the typical color of alpha hemolysis?
5-25: Blood Agar
What does beta hemolysis look like on blood agar? What are bacteria doing to RBC’s to produce the typical appearance of beta hemolysis?
5-25: Blood Agar
Which pathogen is an example of a beta hemolytic organism? What disease does this organism cause? What is the significance of being a carrier of this organism?
5-25: Blood Agar
Define “normal microbiota” (“normal flora”).
5-25: Blood Agar
Besides the organism mentioned in #20, another beta-hemolytic pathogen is the nosocomial organism that produces a golden-yellow pigment and also causes a food borne illness, __________________________.
5-25: Blood Agar
What does it mean to say that an organism is “fastidious”?
5-25: Blood Agar
Hemolysins produced by bacteria of the genus Streptococcus are called ________________________.
5-25: Blood Agar
