RT Journal Article SR Electronic(1) A1 Bayer, Edward A. A1 Skutelsky, Ehud A1 Goldman, Sara A1 Rosenberg, Eugene A1 Gutnick, David L.YR 1983 T1 Immunochemical Identification of the Major Cell Surface Agglutinogen of Acinetobacter calcoaceticus RAG-92 JF Microbiology, VO 129 IS 4 SP 1109 OP 1119 DO https://doi.org/10.1099/00221287-129-4-1109 PB Microbiology Society, SN 1465-2080, AB The immunochemical and immunocytochemical characteristics of three Acinetobacter calcoaceticus RAG strains were compared in order to clarify the relationship between antibody-induced agglutination and the production of polyanionic extracellular emulsifier (termed emulsan). In addition to the parent, RAG-92, two mutant strains were examined: (1) a nonagglutinating emulsan-producer (AB15), and (2) an agglutinating mutant (16TLU) defective in the production of emulsan. A combined genetic-immunochemical approach was employed. This included the comparison of crossed Immunoelectrophoresis patterns of parent and mutant supernates and the effect of absorption of anti-whole cell antiserum with mutant cells. In addition, agglutinability and competition studies were performed as well as electron microscopic cytochemistry. The results demonstrated that three major antigenic components were associated with the cell surface and the supernate. Mutant cells were altered both in their cell surface properties and in their extracellular products. One antigenic component, termed component C3, was the major cell surface agglutinogen; this component was absent in nonagglutinating mutants. Component C3 may be identical with or attached to the 300 nm projections on the parent cell surface, but it is not directly related to the presence of emulsan. It appears that emulsan plays little or no role in the phenomenon of antibody-induced agglutination of this organism., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-129-4-1109