Use of a murine O-antigen-specific monoclonal antibody to identity Acinetobacter strains of unnamed genomic species 13 Sensu Tjernberg and Ursing

A monoclonal antibody against the O-antigenic polysaccharide chain of the l ipopolysaccharide (LPS) of Acinetobacter strains belonging to the unnamed g enomic species 13 Sensu Tjernberg and Ursing (13TU) was obtained after immu nization of BALB/c mice with heat-killed bacteria and was characterized by enzyme immunoassay and Western blot analysis, by use of LPS and proteinase K-treated bacterial lysates, analyses in which the antibody was shown to be highly specific for the homologous antigen. In addition, when tested in do t and Western blots, reactivity was observed with 9 of 18 Acinetobacter str ains of genomic species 13TU which had been isolated in Germany and Denmark ; no reactivity was observed with strains of other genomic species, includi ng the closely related genomic groups 1 (A. calcoaceticus), 2 (A. baumannii ), and 3 (unnamed), or with other gram-negative bacteria. The antibody desc ribed here represents a convenient reagent for the simple, economical, and accurate differentiation of clinical isolates of genomic species 13TU from other Acinetobacter strains. Although the antibody does not identify all is olates of this genomic group, it is evident that it will be a useful reagen t in the development of a serotyping scheme for clinical laboratories.