Staph A infection Flashcards
What is the most virulent bacteria of the staphylococcal species?
Staph aureus
Is staph aureus part of the normal human flora?
Yes
The rate of colonisation of staph A is higher amongst which patients?
Insulin-dependent diabetes (mainly T1)
HIV infection
Patients undergoing haemodialysis
Individuals with skin damage (vagina, axillal, perineum + oropharynx)
Classifications of staph A according to the environment of acquisition
Healthcare associated
Community acquired
What can Staph A infections present with?
Skin & Soft Tissue Infections
Localised pyogenic staphylococcal infections - cyst-like
Deep-seated abscesses, necrotising fasciitis, pyomyositis
Osteomyelitis, septic arthritis, discitis
Infective endocarditis
Pneumonia, Empyema
In the hospital setting- wound infection and vascular line- or catheter-related infection
What do approx 1/3 of patients with staph a bacteraemias develop?
Local complications or distant septic metastases
Common sites of distant septic metastases associated with staph A infection
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
Investigations for suspected staph A infection (6)
Microscopy and culture of specimens.
Multiple blood cultures before commencing antibiotic therapy.
Repeat blood cultures are recommended 48–72 hours after commencing antimicrobial therapy.
Biopsy samples may be of value for bone infections
Imaging- X-ray, CT, MRI, Radionuclide imaging
Transthoracic echocardiography (TTE), TOE
Treatment of staph A infection
Antibiotic therapy - don’t delay administration
Source identification and clearance
and appropriate surgical intervention
Which antibiotics are commonly used?
Flucloxacillin - 14 days min
Vancomycin - not as good, poor tissue penetration etc (used if allergic to penicillin)
Teicoplanin
Linezolid - bacteriostatic
