Staphlocci and streptococci

Question 1

How do staphs appear?

Answer 1

They appear as clumps

“Like a bunch of grapes”

Question 2

Name three important strains of staph?

Answer 2

S. aureus
S. haemolyticus
s. saprophyticus

Question 3

Where do you get s. aureus from?

Answer 3

boils, impetigo, sepsis

Question 4

where do you get s. haemolyticus from?

Answer 4

infected IV lines and catheters

Question 5

Where do you get saprophyticus from?

Answer 5

UTIs

Question 6

What is the most common classification system for staphs?

Answer 6

kloos and schleifer system

Question 7

what is the kloos and schleifer system?

Answer 7

the most common classifcation system for staphs

Question 8

what can the kloos and schleifer system do?

Answer 8

name 30+ strains by name

concerned predominantly with animal strains

Question 9

Where can staphs grow?

Answer 9

on a wide range of media

Question 10

how do staphs appear on media?

Answer 10

as white creamy colonies (depending on species)

Question 11

what are the two main catagories of staphs

Answer 11

coagulase positive and coagulase negative

Question 12

give an example of coagulase positive staph?

Answer 12

s.aureus.

Question 13

what % does s. aureus colonize?

Answer 13

40% of the noses of the population and 70% of the noses of hospital populations

Question 14

which staphs are coagulase negative?

Answer 14

the vast majority

Question 15

what do coagulase negative staphs colonize?

Answer 15

man and animal skin. They are usually species specific.

Question 16

Name a way to distinguish between s. aureus and CNS, besides coagulase test.

Answer 16

DNAase production, as only aureus is positive

Question 17

what do staphs cause?

Answer 17

diseases from food poisoning to life threatening infections such as septicaemia.

Question 18

what are the most common organisms in hospital infections?

Answer 18

staphs

Question 19

Name 12 enzymes and other virulence factors of staphs LPD CCC BC FC SSH

Answer 19

Lipase, phosphatidylinositol, DNAase, Capsule, Catalase, Coagulase, bound coagulase, free coagulase, Staphlokinase, Staph A protein, Hyaluronidase.

Question 20

What does Lipase do for staphs?

Answer 20

Degrades lipids, it is important in boil formation.

Question 21

What does phosphatidylinositol-Specific phosopholipase C do for staphs?

Answer 21

It makes tissues susceptible to activated complement

Question 22

What does DNAase do for staphs?

Answer 22

It degrades DNA

Question 23

What does hyaluronidase do for staphs?

Answer 23

It breaks down interstitial hyaluronic acid. it is a spreading factor.

Question 24

What does coagulase do for staphs?

Answer 24

It has a thrombin-like activty. It inhibits phagocytosis by coating cocci and PMNs with fibrin.

Question 25

What does bound coagulase do for staphs?

Answer 25

It is a ‘clumping factor’. It is attached to cell walls. It has a direct action on fibrinogen.

Question 26

What does free coagulase do for staphs?

Answer 26

It is secreted and interacts with coagulase reacting factor to form a ‘thrombin-like complex’

Question 27

what does staphlokinase do for staphs?

Answer 27

Fabrinolytic, it converts plaminogen to plasmin, causing clot lysis.

Question 28

What does catalase do for staphs?

Answer 28

it breaks down h2o2, and preserves microbe viability.

Question 29

what does teichoic acid do for staphs?

Answer 29

It aids in adherance and colonization.

Question 30

What does the capsule do for staphs?

Answer 30

It inhibits phagocytosis & promotes adherence.

Question 31

What does staph A protein do for staphs?

Answer 31

It is a structure component that inhibits opsonisation by absorption of IgG. It causes the activation of complement, triggering an allergic reaction.