Antimicrobial c

Question 1

what is gram positive bacteria

Answer 1

a bacteria with a thick peptidoglycan layer
- purple under gram stain

Question 2

what is a gram negative bacteria

Answer 2

a bacteria with thin peptidoglycan layer and a outer layer made up of lipopolysaccharides
- pink under gram stain

Question 3

what are the types of gram positive bacteria

Answer 3

• bacilli, rod shaped
• cocci, round shaped

Question 4

what are the types of bacilli gram positive bacteria

Answer 4

• aerobic, spore forming/non-spore forming
  -anaerobic, spore forming

Question 5

what is the bacteria species
- gram + aerobic spore forming
- gram + aerobic non-spore forming

Answer 5

• spore forming, bacillus species
  bacillus cereus ( food poisoning )
  bacillus anthracis ( anthrax )
• non spore forming, corynebacterium
  causes diphtheria

Question 6

what is the bacteria species
- gram + anaerobic spore forming

Answer 6

• clostridium difficle
  causes diarrhoea
• clostridium tetani
  causes of tetanus due to toxin acting on CNS
  Toxoid used for immunisation

Question 7

what are the types of cocci gram positive bacteria

Answer 7

• streptococci (chains)

-staphylococci (clusters)

-entrococci

Question 8

how to split streptococci

Answer 8

haemolysis

-partial (alpha), turns blood agar green

-complete (beta), turns blood agar clear
group A,B important

Question 9

how to split staphylococci

Answer 9

coagulase test

positive
or
negative

Question 10

what bacteria species
- streptococci Alpha
- streptococci Beta
- streptococci non-haemolytic
- enterococci

Answer 10

• streptococci Alpha
  streptococcus pneumoniae - flora, upper resp. tract
  viridian’s streptococci - flora, mouth
• streptococci Beta
  streptococcus pyogenes (group A) - cause sore throat
  streptococcus agalactiae (group B)
• streptococci non-haemolytic
  enterococcus faecalis (group D) - Gut commensal, cause UTI