Microbiology Flashcards
Osteomyelitis
Inflammation of bone and medullary cavity
Usually in one of the long bones
Where does Osteomyelitis most commonly affect in children vs adults?
Children - long bones
Adults - vertebrae
How do you give antibiotics in bone infections?
IV - better bone penetration
Esp important for fluxloxacilin
Where does Osteomyelitis most commonly affect in children vs adults?
Children - long bones
Adults - vertebrae
Most common microbial cause of Osteomyelitis?
Staph aureus
Treatment of Osteomyelitis
Acute - IV flucloxacillin (with rifampcin???)
May require surgery to remove sequestrum
Investigation of Osteomyelitis
What must you await before starting treatment?
MRI - ideal for imaging
Gold standard = bone biopsy
+ wound swabs/blood samples (not always diagnostic)
Await microbiological diagnosis before treatment UNLESS SEPSIS
When would you suspect osteomyelitis in fractures?
Non-wound healing bones
More common in open fractures
How do you diagnose osteomyelitis in diabetic ulcers?
Probe to bone is most senstitive ?
If patient is penicillin resistant what antibiotic will be used in place of flucloxacillin?
Vancomycin
What is the oral switch for IV fluxocillin?
Oral doxycline (better bone penetration)
What genetic condition is associated with osteomyelitis?
Sickle cell
Gaucher’s disease
How would vertebral osteomyelitis present?
How long do you keep up treatment?
Insidious pain and tenderness in back
Raised inflam markers
Drainage of infection and antibiotics for min. 6 weeks
Difference between osteomyelitis and osteitis?
osteomyelitis is an inflammation caused by infection
osteitis just an inflammation of bone
Prosthetic joints infection is most typically caused by?
Staph aureus
Staph epidermis - vancomycin
When does most prosthetic infection present?
How is most infection caused?
When does infection become classified as chronic?
1-3 months post op
Introduced during surgery
3 months post op
What is stage 1/2 revision involved in prosethic treatment?
Remove prosthetic - give 6 weeks of antibiotics and then return antibiotic
Some centres will immediately insert a new prosthetic but just make sure v well washed
What bacteria found in the biofilm is responsible for majority of symptoms?
Planktonic bacteria
What can loosing of PJ be suggestive of?
Infection
What is important when taking perioperative tissue samples?
Take multiple - if many come back positive for same bacteria
Increased signficance
PJ infection treatment
DAIR (debridement, antibiotics adn implant retention)
2 stage exchange - remove for period of time and do aggresive antibiotic treatment
12 weeks in DAIR
6 weeks in 2 stage
Rifampicin always as companion drug
Why must you take a blood culture?
Bacteriaemia is present in most patients and so important for treating correctly
If cystals present in joint fluid in septic arthritis what could it be?
Viral arthritis
