ANTIGENIC ANALYSES OF CILIA-ASSOCIATED RESPIRATORY (CAR) BACILLUS ISOLATES BY USE OF MONOCLONAL-ANTIBODIES

Mouse monoclonal antibodies (MAbs) developed to a rat isolate (R-3) of cilia-associated respiratory (CAR) bacillus were used to assess antig enic relationships among three rat and five rabbit CAR bacillus isolat es. Evaluation of MAbs by enzyme-linked immunosorbent assays (ELISAs) indicated that 87 of 241 hybridomas secreted CAR. bacillus-reactive an tibodies that could be grouped into four major groups. Group-I MAbs re acted with epitopes expressed by all CAR bacillus isolates and at leas t two or more nonrelated species of bacteria. Group-II, -III, and -IV MAbs reacted with only one or more of the rat CAR bacillus isolates; n o MAbs reacted only with rat and rabbit CAR bacillus isolates. Western blot analyses indicated that 41-, 50-, and 105-kDa peptides of rat CA R. bacillus isolates expressed rat CAR bacillus group- and isolate-spe cific epitopes, Hyperimmune anti-CAR bacillus antiserum and serum spec imens from a CAR. bacillus histologically positive mouse and rat also reacted with the 41-, 50-, and 105-kDa peptides. Sera from CAR bacillu s histologically negative rats did not react with these peptides, Thes e results suggest that the 41-, 50-, and 105-kDa peptides may represen t suitable antigens for development of a specific ELISA for detection of rodent. CAR, bacillus infections. Furthermore, these data indicate that use of crude CAR bacillus preparations for either rat or rabbit C AR bacillus ELISAs is inappropriate.