IMMUNOBIOLOGY OF ACINETOBACTER-BAUMANNII AND GENOSPECIES-3

Five representative, taxonomically and serologically defined clinical isolates of Acinetobacter baumannii and genospecies 3, and A. baumanni i strain ATCC 19606 were examined for immunogenicity in rabbits follow ing experimental bacteremia. All rabbits seroconverted as determined w ith the aid of the tube O-agglutination, indirect hemagglutination, an d enzyme-linked immunosorbent assay (ELISA) procedures. Immunoblots de tected over twenty immunogenic, proteinase-K-degradable polypeptide an tigens in trichloroacetic acid extracts, outer membrane protein fracti ons, and mechanically disrupted (type MM2 mixer drill) cell preparatio ns. Sodium periodate-susceptible phenol-water and phenol-chloroform-li ght petroleum lipopolysaccharide (LPS) extracts proved to be immunogen ic for the rabbits as well. Convalescent sera from two patients with d ocumented bacteremia due to genospecies 3, serovar 4, likewise reveale d numerous anti-polypeptide and anti-LPS antibodies comprising the imm unoglobulin G (IgG) and the IgM class.