Gram Positive bacteria

Question 1

Symptoms of Staphylococcus Aureus infection

Answer 1

1. Shoulder pain
2. Pyrexia
3. MRI scan shows disc infection and osteomyelitis C6 + C7

Question 2

What is osteomyelitis

Answer 2

Bacterial Infection of the bone causing weakness

Question 3

How is infection with staphylococcus aureus treated

Answer 3

With flucloxacillin for 3 months

Question 4

What is flucoxacillin

Answer 4

Antibiotic

Question 5

How many species of staphylococcus are there

Answer 5

40

Question 6

What can staphylococcus be divided into

Answer 6

Coagulase positive or negative

Question 7

What is a coagulase

Answer 7

Enzyme produced by bacteria that clots blood plasma.

Question 8

Advantage of a bacteria being coagulase positive

Answer 8

The fibrin clot formed around the bacteria may protect from phagocytosis

Question 9

Why are some strains of staphylococcus coagulase -ve

Answer 9

They can attack in opportunistic infections

Question 10

Where are staphylococcus usually found

Answer 10

Nose and skin

Question 11

How is staphylococcus. aureus spread

Answer 11

Aerosol and touch

Question 12

What is MRSA resistant to

Answer 12

1. Beta-lactams
2. Gentamicin
3. Erythromycin
4. Tetracycline

Question 13

What are four virulence factors that are released by staph. aureus

Answer 13

1. Pore-forming toxins
2. Proteases
3. Toxic Shock Syndrome Toxin
4. Protein A

Question 14

Name the pore-forming toxin produced by staph. aureus

Answer 14

Alpha-haemolysin and PVL

Question 15

Name the protease released by staph. aureus

Answer 15

Exfoliatin

Question 16

How does TSST effect the body

Answer 16

Stimulates cytokine release

Question 17

What is protein A

Answer 17

Surface protein that binds Igs in the wrong orientation

Question 18

What three associated conditions with coagulase negative gram positive bacteria

Answer 18

Endocarditis
Septicaemia
Infected imlants

Question 19

What are some associated conditions with pyogenic bacteris

Answer 19

1. Wound infections
2. Abscesses
3. Septicaemia
4. Pneumonia
5. Endocarditis
6. Osteomyelitis

Question 20

What are three associated conditions with toxin-mediated bacteria

Answer 20

1. Scalded skin syndrome
2. Toxic shock syndrome
3. Food Poisoning

Question 21

Name two coagulase-negative staphylococci

Answer 21

S. epidermidis

S. saprophytic

Question 22

Where are S. epidermis commonly found

Answer 22

Infections in debilitated catheters and prostheses (remember, these are opportunistic bacteria as they are coagulase -ve)

Question 23

What do S. saprophyticus cause

Answer 23

Acute cystitis

Question 24

How does S. saprophyticus cause infection

Answer 24

Produces urease which -> kidney stones

Haemagglutuinin for adhesion

Question 25

What symptoms are associated with Streptococcus progenies

Answer 25

Fever

Malaise

Question 26

What would I see in an agar plate if Strep. progenies is found

Answer 26

1. Beta-haemolytic (causes lysis of red cells around the colony)
2. Facultatively anaerobic
3. Penicillin sensitive

Question 27

What is alpha haemolysis

Answer 27

Partial haemolysis (H202 reacts with Hb)

Question 28

What bacteria causes partial haemolysis

Answer 28

S. intermedius

Question 29

What is Beta haemolysis

Answer 29

Complete lysis

Question 30

What is gamma haemolysis

Answer 30

No lysis at all

Question 31

What three ways can streptococci be classified as

Answer 31

1. Haemolysis
2. Lancefield typing
3. Biochemical properties

Question 32

What is lance field grouping

Answer 32

A method of grouping catalase negative, coagulase negative bacteria based on bacterial carbohydrate cell surface antigens

Question 33

Describe how lance field grouping is carried out

Answer 33

Antiserum is added to each group of suspension of bacteria

1. Clumping indicates recognition

Question 34

What infections are caused by S. progenies

Answer 34

1. Wound infections causes cellulitis
2. Tonsillitis + pharyngitis
3. Otitis media
4. Impetigo
5. Scarlet fever
6. Complications
   - rheumatic fever
   - glomerulonephritis

Question 35

What factor does S. progenies release

Answer 35

Hyaluronidase for spreading

Streptokinase - breaks down clots

C5a peptidase - reduce chemotaxis

Question 36

What toxins are released by S. progenies

Answer 36

Streptolysins O + S - binds cholesterol

Erythrogenic toxin - SPeA t ogive exaggerated response

Question 37

What surface receptors do S. progenies have

Answer 37

Hyaluronic acid on capsule for protection

M proteins which encourages complement degradation

Question 38

Symptoms of S. pneumonia

Answer 38

1. Nasal congestion
2. Fever
3. Severe pain in chest
4. Blood + sputum in culture

Question 39

Why are S. pneumonia found as draughtsman colonies

Answer 39

Flattened, depressed centre in colony

Question 40

Where does the colony of S. pneumoniae start at

Answer 40

Oropharynx (30% of pop)

Question 41

What does S. pneumonia cause

Answer 41

Pneumonia, otitis media, sinusitis, meningitis

Question 42

What three factors can predispose you to S.pneumoniae infections

Answer 42

1. Impaired mucus trapping from viral infection
2. Hypogammaglobulinaemia
3. Asplenia

Question 43

What makes the S. pneumonia inflammatory wall

Answer 43

1. Teichoic acid

2. Peptidoglycan

Question 44

What cytotoxin is produced by S.pneumonia

Answer 44

Pneumolysin

Question 45

When are polyvalent vaccines to S.pneumoniae given

Answer 45

Those older than 2 who are at risk of infection