title: Human serum bactericidal activity against Serratia marcescens: failure of human, "natural," specific anti-O IgG antibodies to enhance serum bactericidal activity.
abstract: A commercial, low pH-derived, intravenously applicable human IgG immunoglobulin preparation (Sandoglobulin) revealed O-agglutinin activity against 16 of the 21 O-antigens of Serratia marcescens, although at low titers; this IgG preparation lacked H-immobilizing antibodies against this microorganism. The bactericidal activity of 65 vol% of normal, fresh human serum was neither enhanced nor significantly antagonized following addition of 25 vol% of undiluted or 1:4 diluted. Sandoglobulin, as determined with test strains of S. marcescens that represented various human serum susceptibility categories. This indifferent effect was obtained despite documented O-agglutinin activity directed against several of the assay strains. It was concluded tentatively, that human, "natural" anti- S. marcescens IgG antibodies failed to augment human serum bactericidal activity in vitro against this opportunistic-pathogenic microorganism.
mesh_terms: D000373:Agglutinins / Q000032:analysis / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000276:immunology*; D001770:Blood Bactericidal Activity; D004926:Escherichia coli / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D007074:Immunoglobulin G / Q000276:immunology*; D012706:Serratia marcescens / Q000145:classification / Q000276:immunology*
chemical_list: D000373:Agglutinins; D000907:Antibodies, Bacterial; D007106:Immune Sera; D007074:Immunoglobulin G