Lab 2 - Normal Flora and Pathogenicity Flashcards
What are the different bacteria that can be found on human skin?
Propionibacterium, Micrococcus, and Staphylococcus
How can the bacteria on our skin be classified?
Micrococcus = aerobes Staph = facultative Propioni = anaerobes
Where can the anaerobes in our skin be found? What are they called?
Propionibacterium
Hair canals
Forehead and armpit too????
What is RCAF?
Reinforced Clostridial Medium with Furoxone
Why did we use it in our lab?
Because we could use it so that only different species of Propionibacterium could grow on it.
How did RCAF prevent growth of some things?
The GasPak was used to create anaerobic conditions, thus inhibiting growth of micrococcus.
Furaxone allowed the inhibition of Staphylococcus.
Can you differentiate with what has grown on the RCAF plates?
Yes.
Different propionibacterium species can be differentiated by the colour of the colonies and texture.
Where can Staphylococcus aureus and epidermis be found?
On the skin and nasal passages
What kinds of pathogenic infections can they cause?
Boils, carbuncles, impetigo, meningitis, urinary tract infections, and food poisoning
What is a “staph carrier?”
A person who carries pathogenic staph normally.
What type of staphylococcus is more dangerous?
Staph epidermidis is less invasive. But if it does cause disease, lesions are usually restricted to small abcesses.
How can Staph aureus be distinguished from epidermidis?
Staph aureus ferments mannitol and produces coagulase
What does coagulase do?
It causes fibrin in the blood plasma to clot
What type of medium was used in this part of the lab?
Mannitol salt agar plate
How does MSA select for staph?
It contains a high concentration of salt, which is inhibitory to most other bacteria
