title: Failure of a commercial, intravenously applicable IgG F (ab)2 preparation (Gamma-Venin) to enhance human serum bactericidal activity against Serratia marcescens.
abstract: A commercially available, intravenously applicable, pepsin-derived human IgG F (ab)2-fragment preparation (Gamma-Venin) revealed O-agglutinin activity against 12 of the 21 currently established O antigens of Serratia marcescens; however, this preparation lacked H-immobilizing antibodies against all 20 H antigens of this microorganism. The addition of 25 vol% of the IgG F (ab)2-fragment preparation of 65 vol% of fresh human serum neither enhanced nor antagonized serum bactericidal activity against selected assay strains of S. marcescens that represented various human serum susceptibility categories. This indifferent effect was obtained despite documented O-agglutinin activity against the O antigens of several of the "delayed-serum sensitive" and "pseudo-serum resistant" assay strains and against the O antigen of a "genuinely serum-resistant" test strain of S. marcescens.
mesh_terms: D000373:Agglutinins / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001770:Blood Bactericidal Activity; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D012706:Serratia marcescens / Q000276:immunology*; D005719:gamma-Globulins / Q000276:immunology*
chemical_list: D000373:Agglutinins; D000942:Antigens, Bacterial; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D005719:gamma-Globulins; C031151:pepsinated immunoglobulin G