Staph.A Bacteraemias Flashcards
what type of clusters does the gram +ve cocci form on stains?
Grape like
in what condisitons is the rate of colonisation highest?
DM, HIV, haemodialysis, individuals with skin damage.
Approximately one-third of patients with S.aureus bacteraemia develop local complications or distant septic metastases. Where are they usually?
Bones and joints (especially when prosthetic materials are present)
Epidural space and intervertebral discs
Native and prosthetic cardiac valves, Cardiac devices
Visceral abscesses in spleen, kidneys and lungs
list off the spectrum of infection for staph.a (types of infections it causes)
Skin & Soft Tissue Infections- S. aureusis the most commonly identified agent.Localised pyogenic staphylococcal infections- furuncles and carbuncles, Deep-seated abscesses, necrotising fasciitis, pyomyositis, Osteomyelitis, Septic arthritis, Discitis, Infective endocarditis, Pneumonia, Empyema
Ix
microscopy and culture of specimens. Repeat blood cultures 72 hrs after commencing antimicrobial therapy. Biopsy samples may be of use for bone infections, xray, mri, ct, echo, radionuclide imaging.
Mx
Antibiotics
Flucloxacillin- minimum duration of treatment for uncomplicatedS. aureusbacteraemia is 14 days.
Vancomycin- far from an ideal drug due to poor tissue penetration, slow bactericidal activity, inconvenient administration and side effects.
Teicoplanin- has an advantage in terms of its single daily dosing and could also be used three times weekly after appropriate loading
Linezolid- bacteriostatic, synthetic oxazolidinone, good penetration into bone and excellent oral bioavailability.
Daptomycin- cyclic lipopeptide with rapid bactericidal activity againstS. aureus. Well tolerated. Has the advantage of once daily dosing.
Case 1…
47 year old lady with a background history of Injecting drug use presents to hospital with 5 day history of fever, cough and shortness of breath. She also complained of a painful swollen right groin.
She was alert and orientated on examination. O2 saturations were 90% on air, She was pyrexial at 38.5C. BP was 110/60, Pulse rate was 110 bpm, Respiratory rate was 32.
She did not have any known allergies, No history of travel.
Bloods showed- WCC 31.9, Urea 8, Dopplar US showed a DVT ? Infected Right leg
Blood cultures were positive for S. aureus. - Despite 2 weeks on therapy, She complains of ongoing cough, fever and right sided chest discomfort and right groin pain and discharge. Bloods showed WCC of 18 and CRP of 210.
what are 3 rf’s for contracting MRSA?
elderly, open wound, hospitalised, nursing home, contact with healthcare workers, overuse of antibiotics
how can you prevent infection spread in a ward?
hand hygiene, barrier nursing, side room, deep cleaning following discharge.
what are 3 sites swabbed in routine MRSA screening?
nose, groin, armpit.
