title: Immune evasion by staphylococci.
abstract: Staphylococcus aureus can cause superficial skin infections and, occasionally, deep-seated infections that entail spread through the blood stream. The organism expresses several factors that compromise the effectiveness of neutrophils and macrophages, the first line of defence against infection. S. aureus secretes proteins that inhibit complement activation and neutrophil chemotaxis or that lyse neutrophils, neutralizes antimicrobial defensin peptides, and its cell surface is modified to reduce their effectiveness. The organism can survive in phagosomes, express polysaccharides and proteins that inhibit opsonization by antibody and complement, and its cell wall is resistant to lysozyme. Furthermore, S. aureus expresses several types of superantigen that corrupt the normal humoral immune response, resulting in anergy and immunosuppression. In contrast, Staphylococcus epidermidis must rely primarily on cell-surface polymers and the ability to form a biolfilm to survive in the host.
authors.affiliation: Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland. tfoster@tcd.ie
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Foster
mesh_terms: D000917:Antibody Formation / Q000502:physiology; D001427:Bacterial Toxins / Q000378:metabolism; D002633:Chemotaxis / Q000502:physiology; D003167:Complement Activation; D023082:Defensins / Q000502:physiology; D024881:Drug Resistance, Bacterial; D005098:Exotoxins / Q000502:physiology; D006801:Humans; D007110:Immunity, Active / Q000276:immunology; D007113:Immunity, Innate / Q000276:immunology*; D010587:Phagocytosis; D013203:Staphylococcal Infections / Q000276:immunology*; D013205:Staphylococcal Protein A / Q000378:metabolism; D013207:Staphylococcal Skin Infections / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology* / Q000472:pathogenicity*; D013212:Staphylococcus epidermidis / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001427:Bacterial Toxins; D023082:Defensins; D005098:Exotoxins; D013205:Staphylococcal Protein A; C018579:leukotoxin