Flashcards in Microbiology Deck (20)
List some clinical presentations of acute bone and joint infections
Pain, redness, swelling
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
What is septic arthritis? How can it be introduced?
Infection of the joint space
Blood spread, direct innoculation or from infected bone
What are the main organisms that cause septic arthritis?
List diagnostic investigations for septic arthritis
Blood culture if pyrexial
Joint fluid aspirate for microscopy/culture
USS, XR, CT bone
What is the main empirical treatment for septic arthritis?
Flucloxacillin (Staph. aureus)
N.B. high-dose IV to maximise uptake
If there is a child under 5yrs old with septic arthritis, which antibiotic should be added and why?
Ceftriaxone for H. influenzae/Kingella cover
How long does antibiotic treatment for septic arthritis usually last?
What is osteomyelitis?
Inflammation of bone + their medullary cavity
Which organisms cause chronic osteomyelitis?
Brucella (goat's milk)
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
Which organisms cause type 1 necrotising fasciitis?
Mixed anaerobes and other bacteria
Which organism causes type 2 necrotising fasciitis?
Group A Strep. (flesh-eating bacteria)
List the mainstay treatment for necrotising fasciitis
Pencillin + clindamycin
What is gas gangrene?
Spores forming in tissue, causing accumulation of gas bubbles
What is tetanus?
Neurotoxin produced by Clostridium tetani prevents release of neurotransmitters, causing locked jaw/spastic paralysis
When is vancomycin used empirically instead of flucloxacillin?
If MRSA, diptherioids, or penicillin-allergic
Why is clindamicin useful?
Antitoxin properties - effective against PVL, group A Strep.
Why do bacteria in biofilms pose a problem?
Resistant to immune system and antibiotics