title: Identification of a potentially important antigen of Pasteurella haemolytica.
abstract: To identify antigens which may be important for stimulating immunity to pneumonic pasteurellosis, a bovine antiserum to whole P. haemolytica was used to screen a recombinant lambda gt11/P. haemolytica expression library. One of the recombinant bacteriophage clones identified with the bovine antiserum, SW20C, expressed a fusion protein which was also recognized by rabbit antiserum to partially purified P. haemolytica culture supernatant and was found to be immunogenic in guinea pigs. The guinea pig antibody recognized a 100 kDa protein in P. haemolytica cell lysates. Sequence analysis of the cloned DNA from SW20C identified a fragment of 1446 bp with a small open reading frame that was contiguous with the lacZ sequence. The 153 bp P. haemolytica-specific open reading frame encoded a polypeptide of approximately 6 kDa. Homology searches of Genbank and the EMBL data bases revealed no homology of this open reading frame with any other bacterial sequences including P. haemolytica leukotoxin and Ssa1. Evaluation of sera from calves that were scored either susceptible or resistant to experimental pneumonic pasteurellosis demonstrated a significant (P < 0.001) correlation between the intensity of the antibody response to the SW20C antigen and resistance to disease.
authors.affiliation: Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130.
authors.forename: S K
authors.initials: SK
authors.lastname: Weldon
authors.forename: D A
authors.initials: DA
authors.lastname: Mosier
authors.forename: K R
authors.initials: KR
authors.lastname: Simons
authors.forename: R C
authors.initials: RC
authors.lastname: Craven
authors.forename: A W
authors.initials: AW
authors.lastname: Confer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D002417:Cattle; D007113:Immunity, Innate; D016978:Mannheimia haemolytica / Q000276:immunology*; D008969:Molecular Sequence Data; D012766:Pasteurellosis, Pneumonic / Q000276:immunology* / Q000382:microbiology; D017422:Sequence Analysis, DNA
chemical_list: D000942:Antigens, Bacterial