Flashcards in Bacteriology lab Deck (25):
Recall 2 examples of sterile-site bacteriology cultures
What is chocolate agar and what is it used for?
Cooking released certain nutrients to allow for bacterial growth
Used for: H. influenzae
What is MacConkey agar used for?
Gram neg bacteria
In general what sort of infections are caused by gram pos bacteria?
Skin + soft tissue
In general what sort of infections are caused by gram neg bacteria?
Abdomen and urinary tract
What colour does gram stain turn in gram pos bacteria and why?
Caught in thick peptidoglycan wall
What colour does gram stain turn in gram neg bacteria and why?
Takes up pink counter-stain
Has additional outer membrane to prevent peptidoglycan interaction
Give an example of a gram neg bacterium
Give an example of a gram pos bacterium
Describe the appearance of gram pos cocci on an agar plate
Describe the appearance of gram pos staphyloccocci on an agar plate
What test is used to distinguish what form of staphylococcus is causing an infection?
What is coagulase?
Staphylococcus virulence factor
Give an example of a coagulase positive virus
Name and describe the types of haemolysis
Alpha and beta
Alpha = incomplete
Beta = complete
What bacteria are frequently subjected to haemolysis testing?
How does alpha haemolysis appear?
Turns agar green
Give an example of a bacteria that undergoes alpha haemolysis
How does beta haemolysis appear?
What agar is used to test for salmonella, and how does a positive test show?
(xylose lysine deoxycholate)
Salmonella can't ferment xylose
Pos = goes pink, forms black colonies
What sort of bacteria requires serology testing and why?
Syphillis - can't be cultured
How can serology be used to confirm a chickenpox diagnosis?
Culture taken at beginning of infection and after 10 days should go from IgG neg to pos
How is MRSA resistance tested for?
PCR for resistance gene (MecA)
Recall 2 ways of testing for antimicrobial susceptibility