Staph Aureus Bacteraemias

Question 1

Staph Aureus bacteria

Answer 1

Gram-positive coccoli

- Part of normal flora

Question 2

Staph Aureus colonisation

Answer 2

Sites: anterior nares, skin, vaginal, axilla, perineum, oropharynx

• Reservoir for future infection
• 25-50% colonised

Question 3

Staph Aureus Pathology

Answer 3

• Most virulent of Staphylococcal species

- Toxin-mediated and non-toxin-mediated mechanisms

Question 4

Aetiology

Answer 4

• Healthcare-associated

- Community associated

Question 5

Risk Factors for infection

Answer 5

• Diabetes
• HIV
• Haemodialysis
• Skin damage

Question 6

Spectrum of S. aureus infection

Answer 6

Skin and soft tissue
- Localised pyogenic: furuncles, carbuncles
- Abscess, necrotising fasciitis, pyomyositis
MSK:
- Osteomyelitis, septic arthritis, discitis

• Infective endocarditis
• Pneumonia, empyema

Hospital: wound infection, vascular line-/catheter-related

Question 7

Complications of S. aureus bacteraemia

Answer 7

Local/distant septic metastases

• Bones and joints
• Epidural space and discs
• Cardiac valves, devices
• Visceral abscess: spleen, kidney, lungs

Question 8

Gram stain of S. aureus

Answer 8

Grape-like clusters

Question 9

Examination

Answer 9

• Pyrexia
• Hypotension
• Tachycardia
• Tachypnoea

Question 10

Investigations

Answer 10

• Microscopy and culture
• Blood culture
• Biopsy (bone)
• XR, CT, MRI
• Radionuclide imaging
• ECHO
• TOE

Question 11

Management

Answer 11

IV antibiotics

• Flucloxacillin
• Vancomycin
• Teicoplanin
• Linezoid
• Daptomycin

Source identification and clearance.
Appropriate surgical intervention