s.aureus
s.epidermidis
s.saprophyticus
s..lugdunensis
s.haemolyticus
S. aureus expresses many potential virulence factors
(1) surface proteins that promote colonization of host tissues
(2) invasins that promote bacterial spread in tissues (leukocidin, kinases, hyaluronidase
(3) surface factors that inhibit phagocytic engulfment (capsule, Protein A
(4) biochemical properties that enhance their survival in phagocytes (carotenoids, catalase production
(5) immunological disguises (Protein A, coagulase
(6) membrane-damaging toxins that lyse eucaryotic cell membranes (hemolysins, leukotoxin, leukocidin
(7) exotoxins that damage host tissues or otherwise provoke symptoms of disease (SEA-G, TSST, ET
(8) inherent and acquired resistance to antimicrobial agents
Virulence determinants of Staphylococcus aureus
Invasion
a-toxin (a-hemolysin): most potent membrane-damaging toxin of S. aureus
ß-toxin : a sphingomyelinase which damages membranes rich in this lipid
d-toxin : is a very small peptide toxin produced by most strains of S. aureus
Leukocidin : a multicomponent protein toxin produced as separate components which act together to damage membranes (Only 2% of all of S. aureus isolates express leukocidin, but nearly 90% of the strains isolated from severe dermonecrotic lesions express this toxin
Coagulase and clumping factor
an extracellular protein which binds to prothrombin in the host to form a complex called staphylothrombin. The protease activity characteristic of thrombin is activated in the complex, resulting in the conversion of fibrinogen to fibrin
Staphylokinase
Many strains of S aureus express a plasminogen activator called staphylokinase. This factor lyses fibrin
Avoidance of Host Defenses
Capsular Polysaccharide
Protein A
Leukocidin
Exooxins
Superantigens
enterotoxins and toxic shock syndrome toxin
Superantigens and the non-specific stimulation of T cells. Superantigens bind directly to class II major histocompatibility complexes (MHC II) of antigen-presenting cells outside the normal antigen-binding groove. Up to one in five T cells may be activated. Cytokines are released in large amounts, causing the symptoms of toxic shock
Exfoliatin toxin (ET) : associated with scalded skin syndrome, causes separation within the epidermis, between the living layers and the superficial dead layers
بعدش اینکه ویروس مورای چه قدیمیه 2009 
