title: Luminol-enhanced chemiluminescence for evaluation of type III group B streptococcal opsonins in human sera.
abstract: A luminol-enhanced chemiluminescence (CL) assay was developed to evaluate type III group B streptococcal opsonins. Sera from 11 adults that contained high (greater than 25 microgram/ml), intermediate (3-24 microgram/ml), or low (less than 2 microgram/ml) antibody concentrations were assessed by CL, indirect immunofluorescence (IF), and bactericidal assays. Total CL activity correlated with antibody concentration (P less than 0.005), IgG- and C3-IF values, and phagocytic and bactericidal indices. Heat-stable CL activity correlated with antibody concentration (P less than 0.0001) and was related to IgG-IF values and phagocytic indices. Significant bactericidal activity was demonstrated in all sera containing greater than 2 microgram of antibody/ml, but no bactericidal activity was observed in heat-inactivated sera. Adsorption of heated sera with type III group B Streptococcus abolished CL activity, whereas CL values of MgEGTA-chelated sera were approximately 80% of untreated sera. Thus, type-specific antibody in addition to heat-labile serum factors, including those of the alternative complement pathway, contribute to opsonization of type III group B Streptococcus.
mesh_terms: D000937:Antigen-Antibody Reactions; D003176:Complement C3 / Q000032:analysis; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology; D009895:Opsonin Proteins / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D011724:Pyridazines; D013292:Streptococcus agalactiae / Q000276:immunology*
chemical_list: D003176:Complement C3; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D011724:Pyridazines; D008165:Luminol