Exposure of clinical isolates of Acinetobacter baumannii and genospecies 3 to defibrinated human blood with and without added human 'natural' or (patient) immune antibodies.
Fresh defibrinated blood (65% v/v) from 2 human donors failed to completely kill strains of Acinetobacter baumannii and genospecies 3, representing four serovars each. Although colony counts were reduced > or = 90%, there invariably occurred rebound growth following extended incubation. Neither selected serovar-specific or isolate-homologous (following experimental bacteremia) rabbit immune sera nor three intravenously applicable IgG preparations augmented the bactericidal activity of human blood against six selected strains of A. baumannii and genospecies 3, despite documented antibody contents of all sera and IgG preparations employed. The majority of the sera from 22 patients who were early reconvalescent from systemic infection due to A. baumannii or genospecies 3, showed raised IgM antibody titers, and all sera demonstrated markedly elevated IgG antibody titers as determined with an enzyme-linked immunoassay. Defibrinated blood from donors B and T failed to completely kill the bacteria inocula of these 22 Acinetobacter isolates. Only one patient serum enhanced the bactericidal activity of human blood in the absence of antimicrobial drug(s), and only 1 patient serum with large amounts of detectable antimicrobial drug(s) effected complete killing of the homologous bacterial inoculum.
Traub
W H
WH
Institut für Medizinische Mikrobiologie und Hygiene, Universität des Saarlandes, Homburg, Deutschland.
Leonhard
B
B
Bauer
D
D
D000150:Acinetobacter / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000097:blood / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D016470:Bacteremia / Q000209:etiology / Q000276:immunology; D001769:Blood / Q000276:immunology; D001770:Blood Bactericidal Activity; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D011817:Rabbits; D013045:Species Specificity
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G