title: Construction and characterization of a live, attenuated apxIICA inactivation mutant of Actinobacillus pleuropneumoniae lacking a drug resistance marker.
abstract: The apxIIC gene of Actinobacillus pleuropneumoniae serotype 7 was inactivated by homologous recombination using a sucrose counter-selectable marker system, resulting in a mutant strain that had no antibiotic resistance marker and expressed an inactivated ApxII toxin. The safety and immunogenicity of the mutant were evaluated in mice. The mutant strain caused no adverse effects in mice at doses up to 2 x 10(9) CFU via the intraperitoneal route while the parental strain induced total mortality at a dose of 2 x 10(7) CFU. Mice vaccinated intraperitoneally with the mutant strain had 100% and 70% protection against homologous (serotype 7) or heterologous (serotype 1, 3) challenge with A. pleuropneumoniae, respectively. The A. pleuropneumoniae mutant strain HB04C- and the counterselection method used in the study show promise in developing effective live vaccines for porcine pleuropneumonia and for other infections diseases of the respiratory system.
authors.affiliation: Laboratory of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China. beiwei@163.com
authors.forename: Weicheng
authors.initials: W
authors.lastname: Bei
authors.forename: Qigai
authors.initials: Q
authors.lastname: He
authors.forename: Lin
authors.initials: L
authors.lastname: Yan
authors.forename: Liurong
authors.initials: L
authors.lastname: Fang
authors.forename: Yadi
authors.initials: Y
authors.lastname: Tan
authors.forename: Shaobo
authors.initials: S
authors.lastname: Xiao
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.forename: Meilin
authors.initials: M
authors.lastname: Jin
authors.forename: Aizhen
authors.initials: A
authors.lastname: Guo
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Lv
authors.forename: Hongliang
authors.initials: H
authors.lastname: Huang
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
mesh_terms: D000189:Actinobacillus Infections / Q000401:mortality / Q000517:prevention & control; D016977:Actinobacillus pleuropneumoniae / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D000818:Animals; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005819:Genetic Markers; D006460:Hemolysin Proteins; D007114:Immunization; D051379:Mice; D009154:Mutation; D011001:Pleuropneumonia / Q000401:mortality / Q000517:prevention & control*; D011995:Recombination, Genetic; D012703:Serotyping; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014774:Virulence
chemical_list: C085361:ApxII toxin, bacteria; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D005819:Genetic Markers; D006460:Hemolysin Proteins; D014613:Vaccines, Attenuated