Lab: Normal Flora Flashcards
(48 cards)
What is the purpose of using selective and differential media in studying normal flora?
To examine the flora of several sites of the body and understand their role in inhibiting pathogen growth.
What are the sites of the body examined for normal flora in this exercise?
- Throat
- Nasal cavity
- Rectum
What is the first step in the procedure for culturing throat flora?
Use a sterile swab to sample the area around the tonsils and inoculate a blood agar plate.
What media is used to culture flora from the nasal cavity?
MSA agar plate
Fill in the blank: To culture the rectum, insert a swab _____ to _____ inch into the rectum.
¼ to ½
What should be done with the swabs after sampling?
Dispose of swabs in the red biohazard bag.
On which day should biochemical inoculations be made under the biosafety hood?
Day Two
What is characterized on the blood agar plate during the second day?
Hemolytic status of the colonies
What two species of Staphylococcus might be identified on the MSA plate?
- Staphylococcus aureus
- Staphylococcus epidermidis
What are the common rectal isolates mentioned in the procedure?
- Escherichia coli
- Enterobacter aerogenes
What biochemical tests should be performed with the selected colony from the EMB plate?
- SIM
- Motility
- Citrate
- MR
- VP
What is the final task on Day Three regarding the rectal colony?
Match the bacterium based on biochemical tests.
What are some common rectal organisms?
Escherichia coli, Citrobacter freundii, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Alcaligenes faecalis, Pseudomonas aeruginosa
These organisms are part of the microbiota found in the rectal area.
What does the ‘+’ symbol indicate in microbiological tests?
Positive reaction
In the context of biochemical tests, a ‘+’ indicates a positive result for that specific test.
What does the ‘-‘ symbol indicate in microbiological tests?
Negative reaction
In the context of biochemical tests, a ‘-‘ indicates a negative result for that specific test.
Which organism shows a positive result for SIM?
Escherichia coli, Citrobacter freundii, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Alcaligenes faecalis, Pseudomonas aeruginosa
SIM tests assess sulfide production, indole formation, and motility.
Which organism shows a negative result for citrate?
Escherichia coli
Citrate utilization tests determine an organism’s ability to use citrate as its sole carbon source.
Which organisms show a positive result for methyl red (MR)?
Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Alcaligenes faecalis, Pseudomonas aeruginosa
MR tests indicate mixed acid fermentation of glucose.
Which organisms show a positive result for Voges-Proskauer (VP)?
Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris
VP tests detect acetoin production from glucose fermentation.
Which organism shows variable motility results?
Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Alcaligenes faecalis
Motility tests determine an organism’s ability to move.
What should be included in the laboratory notebook regarding colony and cell morphology?
Draw and describe all colony and cell morphology for throat, nasal and rectal results
Documenting morphology helps in identification and analysis of organisms.
Why are some organisms termed ‘normal flora’?
They provide value to the well-being of the host
Normal flora can aid in digestion, protect against pathogens, and contribute to immune function.
Fill in the blank: _______ are organisms that are part of the normal microbiota.
Normal flora
Normal flora refers to the microorganisms that typically inhabit a specific environment, such as the gut.
What is normal flora?
Normal flora refers to the community of microorganisms that reside on and within the human body without causing disease.
