Virulence factor | Biological action |
---|---|
Mucoid exopolysaccharide (alginate) | Adherence to epithelium; barrier to phagocytes and antibiotics; inhibits antibody and complement binding |
Protease enzymes | Tissue damage; epithelial cell tight junction separation; degrade fibronectin; cleave antibodies creating non-functional blocking antibodies; inactivate α1-antiproteinase, complement components and cytokines; cleave C3b receptors from neutrophils; stimulate mucus secretion |
Exotoxin A | Cytotoxic by inhibiting protein synthesis; toxic to macrophages; T cell mitogen; inhibits granulocyte and macrophage progenitor cell proliferation |
Lipopolysaccharide | Dominant antigenic determinant on cell surface; loss of sugar unit side chains during chronic infection creates “rough” LPS and serum sensitivity; less potent endotoxin properties than other Gram-negative species |
Pigments eg. pyocyanin, 1-hydroxyphenazine, pyoverdin | Inhibit ciliary beat; siderophores; toxic to other bacterial species and human cells; enhance oxidative metabolism of neutrophils; inhibit lymphocyte proliferation |
Phospholipase C | Haemolysis; tissue damage; destroy surfactant |
Rhamnolipid | Haemolysis; inhibit ciliary beat; stimulate mucus secretion, affect ion transport across epithelium |
Pili | Adherence to epithelium |
Lipase | Tissue damage |
Histamine | Impair epithelial integrity |
Exoenzyme S | Adherence to epithelium; cytotoxic |
Leukocidin | Cytotoxic to neutrophils and lymphocytes |
Compiled from references 2, 3, 10, 11, 25, 26, 31–35, 41, 42,49, 64, 68, 78, 81, 82.