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Flashcards in Microbiology Deck (20):
1

List some clinical presentations of acute bone and joint infections

Temperature
Pain, redness, swelling
Reduced mobility

2

Define SIRS

2+ of
Temp less than 36 or more than 38
Heart rate more than 90
Resp rate more than 20
PaCO2 less than 4.3kPa
WBC more than 12k or less than 4k

3

What is septic arthritis? How can it be introduced?

Infection of the joint space
Blood spread, direct innoculation or from infected bone

4

What are the main organisms that cause septic arthritis?

Staph. aureus
Streptococci

5

List diagnostic investigations for septic arthritis

Blood culture if pyrexial
Blood tests
Joint fluid aspirate for microscopy/culture
USS, XR, CT bone

6

What is the main empirical treatment for septic arthritis?

Flucloxacillin (Staph. aureus)
N.B. high-dose IV to maximise uptake

7

If there is a child under 5yrs old with septic arthritis, which antibiotic should be added and why?

Ceftriaxone for H. influenzae/Kingella cover

8

How long does antibiotic treatment for septic arthritis usually last?

2-4 weeks

9

What is osteomyelitis?

Inflammation of bone + their medullary cavity

10

Which organisms cause chronic osteomyelitis?

Mycoplasma
Pseudomonas
Salmonella
Brucella (goat's milk)

11

Treatment and diagnosis of osteomyelitis is similar to septic arthritis. What is the key difference in terms of treatment length?

4-8 weeks duration of antibiotic treatment

12

Which organisms cause type 1 necrotising fasciitis?

Mixed anaerobes and other bacteria

13

Which organism causes type 2 necrotising fasciitis?

Group A Strep. (flesh-eating bacteria)

14

List the mainstay treatment for necrotising fasciitis

Surgical debridement
Pencillin + clindamycin

15

What is gas gangrene?

Spores forming in tissue, causing accumulation of gas bubbles

16

What is tetanus?

Neurotoxin produced by Clostridium tetani prevents release of neurotransmitters, causing locked jaw/spastic paralysis

17

When is vancomycin used empirically instead of flucloxacillin?

If MRSA, diptherioids, or penicillin-allergic

18

Why is clindamicin useful?

Antitoxin properties - effective against PVL, group A Strep.

19

Why do bacteria in biofilms pose a problem?

Resistant to immune system and antibiotics

20

Why are superficial wound swabs a waste of time?

Reflect skin flora rather than deep infection (coag neg Staph. are part of flora)