[LAB] Exercise 10A: Throat Culture Flashcards
A diagnostic test to detect presence of microorganisms in the upper respiratory tract
Throat culture/Throat Swab
The most important pathogen causing strep throat
Streptoccocus pyogenes
What microorganism can also be recovered and is associated with tonsillar abscess?
Staphyloccocus aureus
What other indigenous flora can be detected in throat culture?
Viridans streptococci
Beta hemolytic strep (Group A,B,C)
Staphyloccoci
Haemophilus
Moraxella
Anaerobic Bacteria (Clostridium spp.?)
Gram-negative coliform bacteria that is also detected in throat culture
Klebsiella
A sterile tongue depressor is used to apply pressure on the tongue to visualize what?
tonsillar fossae and posterior pharynx
In the collection of throat swab specimens, 1-2 sterile swabs is extended between?
Tonsillar pillars (golden arches) and behind the uvula
Which sites should we avoid in collecting throat swab specimen?
Tongue
Buccal mucosa
Uvula
Rub the sterile swabs back and forth across the?
Posterior pharynx
Tonsillar areas
Any inflamed or exudative areas
T/F: Do not collect specimens if the epiglottis is inflamed
True
Collecting specimens from an inflamed epiglottis can lead to?
Respiratory obstruction
Where are swabs placed after collection?
Sterile tube or transport media
T/F: All culture media (BAP, CAP, PEA, EMB) should be brought at 37C prior to inoculation
False
Room temperature
Firmly roll the swab on to BAP over ____ portion of the BAP surface
1/6th
T/F: Using the same swab from BAP, the swab is rolled as well into CAP, PEA, and EMB.
True
What streaking method is used?
Isolation/four quadrant method
Where is the Taxo A disk placed in the inoculated BAP?
Junction of 1st and 2nd quadrants
How much is the distance of Taxo A disk from the edge?
10-mm from the edge
What is the component of Taxo A Disk?
0.04 units Bacitracin
Inoculated plates are incubated at what temperature?
37C
What is the incubation time for the inoculated plates?
18-24 hours
Growth can be further enhanced if the inoculated BAP and CAP are incubated with?
Increased CO2
What can be done to improve detection of hemolysis?
After streaking, carefully stab the BAP several times using the same loop in the streaked and unstreaked areas
In which media can we observe for isolated pinhead colonies and pinpoint colonies that are entire, white or yellow, clear or opalescent, and creamy in appearance?
BAP
T/F: Other colonies that may be present include large, grayish mucoid/slimy colonies
True
In which media can we observe colonies that are similar to BAP but no hemolytic patterns?
CAP
T/F: We also observe for pinpoint and pinhead colonies in PEA
True
Colonies growing on this medium is presumptive as gram-positive cocci
PEA
T/F: Growth is usually seen in EMB
False;
No growth is usually seen
In which media can we observe large purple or colorless colonies if growth is seen
EMB
T/F: It is susceptible if there is no zone of inhibition
False
Interpretation if there is any zone of inhibition
Susceptible
Interpretation if there is no zone of inhibition
Resistant
In the Catalase Test, from which media do we fish 1-2 similar looking isolated pinhead and pinpoint colonies?
PEA or CAP
In the Catalase Test, what is added to the slides mixed with the colonies?
1-2 drops of 3% Hydrogen Peroxide
Positive result of Catalase Test
Bubbling or effervescence
In which media is the colony inoculated from in Gram stain?
BAP or CAP
T/F: Proceed to the succeeding procedure if you obtained a negative catalase test
False
Do not proceed
T/F: If you obtained a positive catalase test, proceed to Coagulase Testing
True
What media is the specimen inoculated from in coagulase test?
BAP or CAP
In the slide coagulase test what is first dropped on a clean grease-free slide?
NSS
After emulsifying colonies in slide coagulate testing, what is added next?
1-2 drops of rabbit plasma
T/F: In the slide coagulase test, the slide is placed on a dark/black cardboard and tilted when observing for macroscopic clumping
True
How long do we observe for macroscopic clumping in slide coagulase test
Around 10 seconds
When is the test considered negative for Slide Coagulate Test?
No clumping occurs after 2 minutes
What test tube is used for Tube Coagulase Test?
Kahn test tube
In tube coagulase test, how much rabbit plasma is placed on the Kahn test tube?
0.5mL
T/F: Pooled human plasma can be used if rabbit plasma is unavailable in Tube Coagulase Test
True
For how long should we incubate the tube coagulase test sample when observing for clots/coagulum?
4 hours
In what temperature should the tube coagulase test be incubated at?
37C
What is the positive result for tube coagulase test?
Clot or coagulum formation
If no clot is seen after 4 hours, what should be done before reporting the tube coagulase test as negative?
Incubate at room temperature for 20 hours
In Mannitol Fermentation Test, from what media are the 2-3 colonies fished out from?
PEA or BAP
In Mannitol Fermentation Test, what streaking method is used?
Simple streaking
In Mannitol Fermentation Test, what is the incubation time and temperature?
24 hours, 37C
Mannitol Fermenter/Non-Mannitol Fermenter: Colonies are yellow and plate becomes yellow
Mannitol Fermenter
Mannitol Fermenter/Non-Mannitol Fermenter: Pink to red plates
Non-mannitol fermenter
Other tests can be performed on which colonies?
Catalase negative and are gram positive cocci in chains
What is resistant to Taxo P (Optochin)?
Viridans streptococci (alpha hemolytic)
T/F: S. pyogenes is PYR postive
True
T/F: S. pyogenes is susceptible to SXT-TMP
False
Resistant
