title: Immunoserological comparison of 104-kilodalton proteins associated with hemolysis and cytolysis in Actinobacillus pleuropneumoniae, Actinobacillus suis, Pasteurella haemolytica, and Escherichia coli.
abstract: A homologous polyclonal antibody was produced in a rabbit to the 104-kilodalton (kDa) protein hemolysin of Actinobacillus pleuropneumoniae serotype 1 strain CM-5. In immunoblots, this antibody recognized a similar 104-kDa protein produced in culture supernatants by A. pleuropneumoniae serotypes 1 to 12 and taxon "Minor group" in addition to Pasteurella haemolytica, Actinobacillus suis, and alpha-hemolysin-producing Escherichia coli (but only weakly in the latter two organisms). These results were reproduced by using a mouse monoclonal antibody to the CM-5 104-kDa protein hemolysin, except that the monoclonal antibody bound more strongly to the alpha-hemolysin produced by E. coli, only weakly to the 104-kDa protein produced by "Minor group," and not at all to any extracellular antigens produced by A. suis. Pigs experimentally infected with A. pleuropneumoniae serotypes 1 to 10 and A. suis produced an antibody that recognized the 104-kDa hemolysin produced by CM-5. A pig challenged with a "Minor group" strain did not have such antibodies. Rabbit antiserum produced against the leukotoxin of P. haemolytica and alpha-hemolysin-producing E. coli also recognized the CM-5 hemolysin, but the latter only weakly. The hemolytic activity produced by CM-5 in culture supernatant was neutralized strongly by the pig serum to serotypes 1, 2, 5, 6, 9, and 10 and A. suis, only partially by serotype 8 antiserum and the rabbit antiserum to P. haemolytica leukotoxin, and not all by the antiserum to serotypes 3, 4, and 7 and "Minor group" and the E. coli alpha-hemolysin. These results indicate that a similar but not identical 104-kDa protein is produced in vitro and in vivo by all serotypes of A. pleuropneumoniae and may be related to cytolysins produced by other gram-negative bacteria.
authors.affiliation: Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Devenish
authors.forename: S
authors.initials: S
authors.lastname: Rosendal
authors.forename: R
authors.initials: R
authors.lastname: Johnson
authors.forename: S
authors.initials: S
authors.lastname: Hubler
mesh_terms: D000188:Actinobacillus / Q000472:pathogenicity*; D000189:Actinobacillus Infections / Q000382:microbiology / Q000662:veterinary; D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology*; D004926:Escherichia coli / Q000472:pathogenicity*; D006460:Hemolysin Proteins / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D009500:Neutralization Tests; D010325:Pasteurella / Q000472:pathogenicity*; D011817:Rabbits; D013552:Swine; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins