Microbiology Case Study Tutorial

Question 1

Chromotogic agar

Answer 1

Coloured to determine different microorganisms

Question 2

Normal flora vs pathogen identification in diagnosis

Answer 2

One microorganism that is normal flora in one part of the body may not be normal flora in another part of the

Question 3

Winpath - what is it?

Answer 3

Laboratory information system in NHS - for GP they do manual request forms for testing which has to be put in manually into the system - other samples have barcode that is scanned for automation

Question 4

Automated systems for microbiology

Answer 4

MALTI-ToF - takes 24h to identify bavcteria
Vitek2 - takes 15 minutes
Have to prepare bacteria first
PCR automation machine detects DNA which we an then detect the bacteria from

Question 5

Sample types in microbiology lab

Answer 5

Pus from absess
Swabs
Tissue
Bone
Urine
Faeces
Non sterile fluids
Bone biopsy

Question 6

Blood culture test in microbiology lab

Answer 6

Blood culture - traffic light system on virtuo analysers - if test is +ve then amber light. Bacteria in blood is transferred to agar, which respires and produces CO2 causes agar colour change

Question 7

Gram stain test in microbiology lab

Answer 7

Crystal violet, iodine, red. Grape +ve = thicker peptidoglycan wall.
Flood with crystal violet, add iodine which creates complex molecules then wash with acetone to break down cell wall.
Gram -ve cell wall broken down quickly but +ve cells kept in cell wall as thicker .
Then stained with natural red - gram -ve stains pink but +ve stays blue.
If we find out -ve or positive and look at shape we can really narrow down what type it is.

Question 8

Gram +ve shapes

Answer 8

Bacilli
Branching filament
Cocci - diplococci, tetrad, chains, clusters

Question 9

Gram -ve shapes

Answer 9

Bacilli
Cocci
Cocci-bacilli
Curved rods

Question 10

What is MALDI-ToF

Answer 10

Mass spec machine - uses light. Time of flight mass spectrometry - 1–15 seconds for result. Molecules disperse - heavy molecules travel slowly and light travels fast

Question 11

What to do if infection occurs- when should we use antibiotic?

Answer 11

We could have intrinsically resistant bacteria - we want bacterialcidal antiboiotic so that normal flora is unharmed. We dont bacterial static.

Question 12

3 bacteria commonly associated with

Answer 12

We could have intrinsically resistant bacteria - we want bacterialcidal antiboiotic so that normal flora is unharmed. We dont bacterial static.

Question 13

Gram -ve shapes

Answer 13

Bacilli
Cocci
Cocci-bacilli
Curved rods

Question 14

MALDI- Tof what is it?

Answer 14

Mass spec machine that used light - time of flight mass spectrometry. 10 - 15 seconds for result. Molecules disperse - heavy molecules travel slowly slowly and light fast

Question 15

What type of antibiotic is usually used?

Answer 15

Bacterialcidal - so normal flora is unharmed. - we dont want bacterialstatic

Question 16

3 bacteria that are commonly associated with food poising in the uk

Answer 16

Salmonella
Shigella
Campylobacter

Question 17

Enterics

Answer 17

Category 3 room - strict access
Never want air from the lab in other rooms - cross contamination. Class 1 hod used. ENtericBio used 0 automated machine - giant pipettes