title: Attenuated Actinobacillus pleuropneumoniae double-deletion mutant S-8∆clpP/apxIIC confers protection against homologous or heterologous strain challenge.
abstract: BACKGROUND
  Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, which leads to large economic losses to the swine industry worldwide. In this study, S-8△clpP△apxIIC, a double-deletion mutant of A. pleuropneumoniae was constructed, and its safety and protective efficacy were evaluated in pigs.
  
  
  RESULTS
  The S-8△clpP△apxIIC mutant exhibited attenuated virulence in a murine (BALB/c) model, and caused no detrimental effects on pigs even at a dose of up to 1.0 × 109CFU. Furthermore, the S-8△clpP△apxIIC mutant was able to induce a strong immune response in pigs, which included high levels of IgG1 and IgG2, stimulated gamma interferon (IFN-γ), interleukin 12 (IL-12), and interleukin 4 (IL-4) production, and conferred effective protection against the lethal challenge with A. pleuropneumoniae serovars 7 or 5a. The pigs in the S-8△clpP△apxIIC immunized groups have no lesions and reduced bacterial loads in the lung tissue after challenge.
  
  
  CONCLUSIONS
  The data obtained in this study suggest that the S-8△clpP△apxIIC mutant can serve as a highly immunogenic and potential live attenuated vaccine candidate against A. pleuropneumoniae infection.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Fang
authors.initials: F
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Yanhe
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China.
authors.forename: Siguo
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, Heilongjiang, People's Republic of China. chunlai.w@hvri.ac.cn.
authors.forename: Chunlai
authors.initials: C
authors.lastname: Wang
mesh_terms: D000189:Actinobacillus Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D017353:Gene Deletion; D051379:Mice; D008807:Mice, Inbred BALB C; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control*; D014774:Virulence
chemical_list: D001428:Bacterial Vaccines
keywords: Actinobacillus pleuropneumoniae; Live attenuated vaccine; Porcine pleuropneumonia