Staphylococcus Identification Flashcards
What is a catalase test?
A test to determine if a species produces the enzyme catalase. H202 is broken down into H2O and O2
How can a catalase test distinguish Strep from Staph
Staphylococcus species produce the enzyme catalase, yielding a positive catalase test. (bubbles)
Strep/Enterococcus species do not produce the enzyme catalase
What are the ingredients in DNAse agar that make it differential?
DNA, Methyl green
What ingredient(s) are in MSA agar that make it selective? What is it selective for?
7.5% NaCl, halotolerant organisms
What ingredient(s) are in MSA agar that make it differential? What is it differential for?
Mannitol, mannitol fermentation
What is the pH indicator in MSA agar?
Phenol red
How does MSA differentiate among the Staph species?
Differential among mannitol fermentation
What does a positive DNAase reaction look like? A negative reaction?
Positive, clearing around the growth
Negative, no clearing
What is a Staph species that is positive for DNAase production?
S. aureus
What is a Staph species that is negative for DNAse production?
S. xylosus
What is a Staph species positive for mannitol fermentation?
S. aureus
What is a Staph species negative for mannitol fermentation?
S. epidermidis
