Staphylococcus aureus: Difference between revisions

Revision as of 09:47, 5 September 2019

Facultative anaerobic, Gram-positive coccus
Catalase and coagulase positive
Microscopy: groups or clusters ("cluster of grapes")
Colony morphology: large, round, golden yellow colonies, often hemolytic on blood agar

Surface proteins for fibrinogen and other substances (used for binding to host endothelial cells)
Membrane-damaging toxins (hemolysins), including Panton-Valentine leukocidin (PVL)
Exfoliative toxins (A and B) which disrupt the junction between epidermal cells, causing scalded skin syndrome
Superantigens that bind to MHC molecules and T-cell receptors, leading to release of huge amounts of cytokines
- Toxic shock syndrome toxin 1 (TSST-1) is implicated in Staphylococcal toxic shock syndrome
- Exotoxins B and C cause Staphylococcal toxic shock syndrome and also food poisoning

Aka Ritter disease
Caused by exfoliative toxin A or B
Essentially bullous impetigo
Sunburn-like, bullous rash that can lead to skin loss (most common in kids with Staph infections of the nasopharynx or skin)

Food poisoning
Staphylococcal toxic-shock syndrome
- Tampon-associated
- Post-surgical (ENT): more of historic with changes in packing
- Surgical site infections, even without obvious signs of localized infection

First-line: vancomycin
Others: linezolid (if lungs) and daptomycin (if blood), but also consider TMP-SMX, ciprofloxacin, doxycycline, and clindamycin

@@ Line 58: / Line 58: @@
 * Food poisoning
 * Staphylococcal toxic-shock syndrome
+** Tampon-associated
+** Post-surgical (ENT): more of historic with changes in packing
+** Surgical site infections, even without obvious signs of localized infection
 == Management ==