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Flashcards in classification of bacteria mw% +++++++ Deck (13)
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1

What are the components of Aerobic Gram Positive cocci?

  • Staphylococci (clusters) 
  • Streptococci and Enterococci (chains)

2

What is the result of coagulase test in differentiating Staphlococci?

Coagulase-positive=Staphylococcus aureus which can be either MRSAor MSSA.

Coagulase negative=nothing

3

Descibe the characteristics of Staphylococcus aureus?

  • Commensal organism carried in nose, axilla, perineum.
  • Wide range of disease from boils/abscesses and soa issue infections to septecaemia and osteomyelits.
  • Commonly penicillin resistant due to production of penicillinase.
  •   

4

What are the coagulase-negative staphylococci?

  • Many different species e.g. S. epidemidis
  • Mainly skin commensals.
  • Form biofilms and may be significant pathogens in the presence of foreign bodies/prostheses e.g. prosthe@c heart

5

What are the properties of Streptococci?

• α- haemolytic (partial haemolysis)

-> turn blood agar green

• β-haemolytic (complete haemolysis)

-> turn blood agar clear

• Non haemolytic

6

Give an example of α-haemolytic streptococci?

Streptococcus pneumoniae

-> pneumonia, meningitis, septecaemia

7

What are the feutures of β-haemolytic streptococci?

  • Further identified by carbohydrate surface antigens.
  • further identified by Groups A-G.

• A, B, F and D clinically most important.

 

8

What are the constituents of Gram positive bacilli?

  • Aerobic 
  • Anaerobic:Clostridium tetani,Clostridium perfringens and Clostridium difficile.

9

What are the feutures of Clostridium difficile?

  • “Difficult” to culture. 
  • Asymptomaticc gut carriage in healthy people

. • Important cause of diarrhoea, associated with toxin production and potentially fatal

10

What are the feutures of Clostridium perfringens?

  • Found in soil and normal commensal in human and animal gut/faeces.
  • Can contaminate food

11

What are the feutures of Clostridium tetani?

  • Toxin production by C. tetani cause tetanus.

• Uncontrolled muscle spasm due to loss of inhibition at neuromuscular junction.

 

12

Gram negative flow chart

13

Gram postive flow chart