Microbiology Flashcards
What are bugs that can affect MSK
S. Aureus Staph, epidermidis Strep pyogenes Gram negatives Anaerobes
What is osteomyelitis
Inflammation of bone and medullary cavity, usually located in one of the long bones
What are different types of of osteomyelitis
Acute vs chronic
Contiguous vs haematogenous ( by spread)
What are the different types of infection
Open fractures Diabetes Vascular insufficiency/ diabetes / neuropathy Haematogenous osteomyelitis Vertebral osteomyelitis Specific host and pathogen
What is the clinical cue with open fractures
Non union and poor wound healing
What is most important with open fractures
Early management is key
Aggressive debridement, fixation and soft tissue cover
Cause is typically staph. Aureus
What is the treatment of diabetes / venous insufficiency infection
Debridement and antimicrobial
What are the ix of diabetes / venous insufficiency
Probe to bone, XR, MRI
What is haematogenous osteomyelitis
Bacteria from blood, often acute presentation
Who gets it? PWID, dialysis, elderly, sickle cell disease, central lines
What’s the risk factors for prosthetic joint infection
Co - Morbidities : RA, diabetes, malignancy, obesity, immunosuppression, lymphdema
Use fo corticosteroids, tumour necrosis factors inhibits
Prior arthroplasty or prior infection at the site of infection
Prolonged duration of surgery
What is the most common cause of prosthetic joint
Direct inoculation at time of surgery ( need prophylaxis)
What are the same bacteria responsible for prosthetic joint infections
- Planktonic bacteria : reproducing rapidly, v active, responsible for most symptoms ( red, fever)
- Sessile bacteria : Dermott, metabolism is low, sensitivity to antibiotic is much lower, forms biofilms, protected by extracellular matrix
Treatment of prosthetic joint infection
Debridement
Antibiotics
Re - implantation
What is a biofilm
A microbe derived sessile community, characterised by cells that are attached to a substratum interface each other
What is the ix of a prosthetic joint infection
Culture ( at least 5 and same organism grow)
CRP
Radiology
