MSK Microbiology Flashcards
Dr B Mooka
what drug is used to treat staph aureus?
Flucloxacillin
what is the side effect in the use of clindamycin?
C. diff
where is adult osteomyelitis likely to occur?
long bone medullary cavity
how do you class osteomyelitis?
by time
acute vs. chronic
name the treatment approach to infection
debridement
antimicrobials
if you can see bone, see tendon and infection, what is the diagnosis?
osteomyelitis
osteomyelitis is a medical emergency.
true or false?
false
only if sepsis too
you must start empiric antibiotics immediately in chronic osteomyelitis.
true or false?
false*
you can afford to wait a few days
how long does debrided tissue take to be covered by soft tissue?
6 weeks
how long is the treatment in osteomyelitis?
6 weeks
coagulase negative staph only really cause problems in those with prosthetics
true or false?
true
coagulase negative staph only virulent in presence of plastic and metal
name examples of osteomyelitis
open fractures diabetes/vascular insufficiency haematogeneous osteomyelitis vertebral osteomyelitis ***
describe staph aureus
common coagulase positive gram positive clusters produce enzymes ***
what is the clue in open fracture infection?
poor wound healing
in diabetes/venous insufficiency, what is the common pathogen?
often polymicrobial but staph aureus is most common
in diabetes/venous insufficiency, what is the treatment?
debridement and antimicrobials
what is the way to tell you what the infection is? best test?
bone biopsy
what drugs do you use for gram negatives?
gentamycin*
what is the alternative to flucloxacillin for people with a penicillin allergy?
vancomycin
name the duration of treatment in diabetic foot infection.
mild - 7days*
moderate - 7days*
severe - 7days*
osteomyelitis - 6 weeks*
what drugs do you use for anaerobes?
metronidazole*
name the drug and allergy alternative and oral switch for gram positive cover.
Flucloxacillin IV
vancomycin if allergic
oral switch - doxycycline
what drug is no use systemically?
vancomycin
topical treatment for bowel i.e. gastroenteritis
who are the likely people to have haematogenous osteomyelitis?
prepubertal children
PWID
elderly
what bone is most commonly affected in haematogenous osteomyelitis?
femur
most common pathogen in endocarditis in PWID?
strep. viridians
in vertebral osteomyelitis, what percentage have fever and what percentage have insidious pain?
50% - fever
90% - insidious pain
what should you avoid in vertebral osteomyelitis initially?
empiric antibiotics
how long should you be on antimicrobials for?
6 weeks minimum
do you need to have pulmonary TB to have vertebral TB?
no - approx 50% do not
what are the risk factors in prosthetic joint infection?
rheumatoidarthritis
diabetes
malnutrition
obesity
what is time scale for early prosthetic infection?
less than a month
later is more than a month
what is a biofilm?
extracellular matrix making a strong barrier to pathogen making it difficult for antimicrobials to work
when is there re-implantation of the joint after infection?
after aggressive antibiotic therapy
what is the classic tetanus - toxin mediated illness?
clostridium tetani
describe clostridium tetani
Gm +ve
what does tetanus cause?
spastic paralysis due to neurotoxin
are survivors immune to tetanus?
NO
