ID Bacteria & Antibiotic Testing Flashcards
What is the catalase test used for? How do you preform it?
- catalase positive organisms include: Staphlococcus, E. coli and Pseudomonas.
- A drop of hydrogen peroxide (H2O2) is added to a bacterial sample on a slide. If bubbles occur, the bacteria contain catalase enzyme.
T/F: The effectiveness of an antibiotic depends on multiple different factors including the ability of the antibiotic to reach the site of infection
True
T/F: Only G- grow on MacConkey agar
True! Only lactose fermenters are able to form (pink) colonies.
Non-lactose fermenters do not grow.
AntiB that kills bacteria is called..?
AntiB that prevents bacteria from multiplying is..?
- Bactericidal kills bacteria
- Bacteriostatic prevents bacteria from multiplying
What are good reasons to test for antiB susceptibility of bacteria?
- Helps us know what antiB to use
- for how long
- dosage
- bacteria resistance
- Coagulase test is preformed on catalase ___ and gram ___
- Staphyloccus a____ is coagulase ___
- Catalase positive & G+
- Aureus is coagulase positive
How do you do a coagulase test? (3)
- Bacteria colony is emulsified in a drop if distilled water/saline to create a thick susp.
- Drop of rabbit plasma & stir w/sterile loop
- Positive reaction + clumping 5 to 20 seconds
Kirby Bauer test (agar diffusion method), what is it? (4)
- Paper disks impregnated w/particular type of antiB
- Agar plate is swabbed so that the entire plate will grow a “lawn”
- AntiB disks are placed at intervals on top of agar
- After 18-20hrs of incubation plate is examined
what agar is most commonly used for antiB testing?!
Mueller Hinton agar!!
Minimum inhibitory concentration (MIC) is the…
- Lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after o/n incubation
- AKA lowest amount of meds needed to stop said bacteria from growing