2: Systemic Bacteriology I Flashcards
Generally, microbes are classified based on their ___.
appearance
Cell walls can be classified as either __ __ or __ __.
Gram positive or Gram negative
Apart from Gram staining, what is another staining method used to identify microbes?
Ziehl Neelson stain
Name three common shapes of bacteria.
Cocci (spheres)
Bacilli (rods)
Spiral-shaped
What are sphere-shaped bacteria called?
Cocci
What are rod-shaped bacteria called?
Bacilli
Apart from spheres and rods, what other shape can bacteria be?
Spiral-shaped
What is a single sphere-shaped bacteria called?
A coccus
What is a bacteria consisting of two cocci in one plane?
Diplococcus
What is a chain of cocci called?
Streptococcus
What is a clump of cocci called?
Staphylococci
What is a rod-shaped bacteria called?
Bacilli
What are slightly curved bacteria called?
(For extra points, what Gram classification are they?)
Vibrio
Gram negative
What are spiral-shaped bacteria called?
Spirillum
What is a spore?
An inert structure which is resistant to physical and chemical challenge
Give an example of a bacterial species which produces spores.
C. difficile
What is a Gram stain?
A purple/violet dye which is RETAINED by Gram positive bacteria
Which type of bacteria retains Gram stain?
Gram positive bacteria
Which type of bacteria doesn’t retain Gram stain?
Gram negative bacteria
What colour do Gram positive bacteria turn after staining?
Dark purple
What colour do Gram negative bacteria turn after staining?
Pink (lighter than purple)
E. coli is Gram…
E. coli is Gram negative
Staph. aureus is Gram…
Staph. aureus is Gram positive
What is a notable organism which doesn’t stain well with Gram stain?
Mycobacterium tuberculosis
Mycobacterium tuberculosis stains (well / poorly) with Gram stain.
poorly
Killed by oxygen
Tolerate oxygen
Grow in oxygen
Require oxygen
Match these definitions to aerobes, obligate aerobes, obligate anaerobes and facultatitive anaerobes.
Aerobes - grow in oxygen
Obligate aerobes - require oxygen
Obligate anaerobes - killed by oxygen
Facultative anaerobes - tolerate oxygen
Microbes can also be classified by their ability/inability to use which gas?
Oxygen
What is selective media?
Media which permits the growth of one organism over others
What is differential media?
Media which facilitates the differentiation of organisms for identification
What are the three types of haemolysis?
Alpha
Beta
Gamma
What is characteristic of Alpha haemolysis?
Greening of the colonies
What are two organisms which show alpha haemolysis (greening)?
Strep. pneumoniae
Strep. Viridans group
What is characteristic of Beta haemolysis?
Gold colouring
What is Gamma haemolysis?
No haemolysis at all
What special test can be used to identify microbes?
MALDI-TOF
In terms of taxonomy, which two bits of information must be included when referring to a microbe?
Genus (e.g Bacillus)
Species (e.g subtilis)
What are some examples of microbiology tests which could be carried out in a clinical environment to identify microbes responsible for disease?
Blood culture
Urine culture
Faeces culture
Pus samples
