Bacterial vaccine that allows differentiation between infected and vaccinated animals, particularly pigs, comprises knock-out mutations in at least three genes, one encoding an immunogenic protein that serves as marker

摘要

Bacterial vaccine (A) for use in an animal, comprises a bacterial infective agent (B) having a knock-out mutation in each of at least three different chromosomal genes (I), where (I) encodes an immunogenic protein (IP), which serves as a marker, in (B). IP generates antibodies (Ab) that are not essential for protective immunity of the animal. Independent claims are included for the following: (1) method for preparing (A); (2) bacterium used in (A); (3) live or inactivated, negative-marker vaccines that include at least one (A); (4) diagnostic method for differentiating between infected animals; animals inoculated with (A) and/or animals both naturally infected and vaccinated; (5) immunogenic proteins (IP), synthesized from at least one (B) in a vaccine (A) that generates Ab, preferably not essential for a protective immune response; (6) nucleic acid (NA) that encodes IP, including at least one mutation for matching the specific codon usage of at least one expression host, particularly Actinobacillus pleuropneumoniae or Escherichia coli; (7) host cell containing the vector of (7); (8) preparation of recombinant IP, encoded by NA, by growing the cells of (8); and (9) recombinant IP prepared by method (9). ACTIVITY : Antibacterial. MECHANISM OF ACTION : Vaccine.