Aureus: latin for gold, produces an antioxidant pigment which gives a golden colour (carotinoids)
Characteristics:
Form: facultative anaerobic gram-positive cocci Family:
Virulence mechanisms:
Enormous range (These lists are not exhaustive) You do not need to memorise these only appreciate the breadth of the virulence factors. Not all aureus have these all but they are present in the wider species
- Toxins (direct damage to cells)
- Panton Valentine Leukocidin (common in MRSA) (Evil)
- a-toxin
- Phenol-soluble modulins
- Epidermolytics
- Superantigens (Drive T cells crazy)
- Enzymes (Invasins) (break down tissue to help Organism spread)
- collagenase
- hyaluronidase
- DNase
- lipase
- Coagulase
- Staphylokinase
- Haemolysins
- Immune system evasion
- Protein A
- Capsule (incorperating fibrin)
- Biofilm
- Adhesion
- MSCRAMMs
- SERAMs
- Teichoic acids
Resistances:
Infection
Areas colonised in the body (Microbiomes):
Exists on skin (30% of people) microbiome (moist sweaty places) but are opportunistic. You can find it basically everywhere in the body
Infectious changes in organism:
Hospital acquired illnesses?
Clinical
Associated illnesses:
Pyogenic skin and soft tissue infections (can coinfect with streptococcus pyogenes)
- Most common cause of:
- Skin
- Wound infections/ surgical site infection
- Abscesses
- HAI
- Can cause:
- Osteomyelitis
- Food poisoning
- Eye infections
- Pneumonia
- Endocarditis
- meningitis
- Sepsis
Testing and identifications:
Performs ß-haemolysis when cultured on blood agar
Catalyse positive in contrast with strept
Forms clusters on staining
Treatment and therapy:
Comments:
Generally causes more abscesses compared to streptococcus pyogenes