Tab. 1.
Virulence factors of S. epidermidis
| Virulence factor | Gene | Function | Reference |
|---|---|---|---|
| Immune evasion | |||
| Biofilm formation | |||
| Primary attachment | |||
| (To abiotic surfaces) | |||
| AtlE | atlE | Bifunctional autolysin/adhesin Abundant protein impacting surface hydrophobicity |
20 |
| Aae | aae | Bifunctional autolysin/adhesin | 77 |
| Teichoic acids | (multiple biosynthetic genes) |
In S. aureus Impact attachment (via binding of autolysins?) |
78 |
| (To matrix proteins) | |||
| SdrF | sdrF | Binds to collagen | 36, 44 |
| SdrG (Fbe) | sdrG | Binds to fibrinogen | 79 |
| SdrH | sdrH | Putative binding function only | 39 |
| Ebp | ebp | Binds to elastin | |
| AtlE/Aae | atlE/aae | Bind to multiple matrix proteins | 32, 38 |
| Intercellular aggregation | |||
| PNAG/PIA | icaADBC | Intercellular polysaccharide adhesin | 49, 53 |
| Biofilm-associated protein Bap/Bhp |
bap/bhp | Intercellular protein adhesin | 21 |
| Accumulation-associated protein Aap |
aap | Intercellular protein adhesin precursor (requires proteolytic processing for activity) |
71, 72 |
| Teichoic acids | Component of biofilm matrix | 80 | |
| Protective exopolymers | |||
| PNAG/PIA | icaADBC | Protects from IgG, AMPs, phagocytosis, complement |
96, 97 |
| PGA | capABCD | Protects from AMPs, phagocytosis | 49 |
| Resistance to AMPs | |||
| SepA protease | sepA | AMP degradation | 81 |
| Dlt, MprF, VraFG |
dltABCD mprF vraFG |
In analogy to S. aureus D-alanylation of teichoic acids (Dlt), lysylation of phospholipids (MprF), putative AMP export (VraFG) |
110–112 |
| Aps system |
apsR (graR), apsS (graS), apsX |
AMP sensor, regulator of AMP resistance mechanisms |
59 |
| Toxins | |||
| Phenol-soluble modulins (PSMs) |
psmα,psmδ, psmε, hld, psmβ1, psmβ2 |
Pro-inflammatory cytolysins | 26, 87, 105 |
| Exoenzymes | |||
| Proteases | |||
| Cysteine protease (SspB, Ecp)(S.aureus staphopain homologue) |
sspB | Unknown, tissue damage? | 82 |
| Metalloprotease/elastase (SepA) |
sepA | Tissue damage?, lipase maturation, AMP resistance |
81, 120, 145 |
| (S.aureus aureolysin homologue) |
|||
| Glutamylendopeptidase (GluSE, SspA, Esp), serine protease |
sspA | Degradation of fibrinogen and complement factor C5 |
82, 83 |
| (S. aureus V8 protease homologue) |
|||
| Lipases GehC, GehD | gehC, gehD | Persistence in fatty acid secretions? | 146–148 |
| Others | |||
| Staphyloferrins |
sfna locus (S.aureus staphyloferrin A) |
Siderophores (iron acquisition) | 149, 150 |
| SitABC | sitABC | Iron importer | 151 |
| Fatty acid modifying enzyme (FAME) |
unidentified | Detoxification of bactericidal fatty acids | 83 |