Laboratory Features Of Bacteria, Viruses & Fungi Flashcards
(32 cards)
How do you use a urine dip test to check for bacteria
Count the amount of white blood cells and see if there is bacteria
What do you have to select the right one of to culture the bacteria
The right agar plate e.g. blood, chocolate, CLED agar
How long does it take to get an accurate idea of the bacteria and how to treat it
48 hours
How long is the incubation period to see the bacteria
Around 24 hours
A better antibiotic has a bigger
Zone of inhibition
When taking a bacteria sample you want it from
A sterile site e.g. cerebrospinal fluid
Sputum is a non-
Sterile site
Why is TB staining different and what do use
You use Zeihl Nelson stain so it is fluorescent and you can now count how many bacteria there are
How are parasites diagnosed
By direct visualisation
What do you need for microscopy
A sample from a sterile site and one pathogen, use gram staining for bacteria
What microscope do you use for viruses
Electron microscope
Once you have got your bacteria culture you can
Visualise colonies, quantify bacteria, purification, do antibiotics susceptibility testing (which is the disk with the ring of zone of inhibition)
API test is only used for
Gram-negative bacteria
What is serology
The detection of antibodies
What is molecular techniques
PCR which is where a small sequence of DNA is amplified and used for further testing
Stages of PCR
Denaturation – heat to 95° C to get single strand of DNA
Annealing of primers – at 50 to 70° C primers bind to their complimentary sequence
Extension of DNA molecules – at 72°C for up to 3 minutes, DNA polymerase binds to the annealed primers and extends the DNA from the 3 end of the chain
What is latency
The ability of infection to remain dormant for long periods of time before reactivation
Tissue culture can test for
Intra cellular organisms
Coccus
Round
Bacillus
Cylinder like
Vibrio
Curved cylinder
Coccobacillus
Oval shape
Spirillium
Loose spiral
Spirochete
Spiral shaped bacteria
