Microbiology Flashcards
describe septic arthritis and how it can spread
infection of the joint space - haematogenous spread, adjacent structures or direct inoculation from trauma or surgery
list some risk factors for developing septic arthritis
IVDU
diabetes mellitus
immunosuppression
pre-existing joint disease
list the most common causes of septic arthritis
staph aureus and streptococci
list causes of septic arthritis specifically in children under 5 and IVDU
children - haemophilus influenzae
IVDU - E. Coli
how does septic arthritis present
monoarthritis
acute presentation of hot swollen, red and painful joint
if multiple joints consider endocarditis
what investigations are carried out for septic arthritis
bloods - CRP and culture
x-ray
joint aspirate of synovial fluid for culture and microscopy
what is the treatment for septic arthritis
flucloxacillin IV 2 weeks then 4 weeks orally
if penicillin allergic give clindamycin + surgical washout
why is swab of lesion not useful in diagnosis
may show normal flora and not cause of infection
what is osteomyelitis
infection of the bone
list the causative organisms of acute and chronic osteomyelitis
acute - staph aureus, haemophilus influenzae and strep
chronic - TB, pseudomonas, salmonella and E. Coli
how is MRSA osteomyelitis treated
IV vancomycin
what is necrotising fasciitis
bacterial infection of soft tissue under the skin, commonly seen on limbs and groin
what organisms cause type 1 necrotising fasciitis
mixed aerobes and anaerobes
what organisms causes type 2 necrotising fasciitis
group A strep (strep pyogenes)
how does necrotising fasciitis present
fever, mild inflammation with out of proportion pain, rapid spread of infection
