title: In vivo induced RTX toxin ApxIVA is essential for the full virulence of Actinobacillus pleuropneumoniae.
abstract: Actinobacillus pleuropneumoniae is a Gram-negative pathogen. It is the aetiological agent of porcine contagious pleuropneumonia (PCP), a severe and highly contagious and severe respiratory disease of swine. Four sets of RTX (repeats in toxin) exotoxins have been described in A. pleuropnuemoniae and three of them have been characterized as important virulence determinants. The aim of this study was to determine the pathogenicity of the invivo induced RTX toxin ApxIVA during infection of piglets with A. pleuropnuemoniae. An A. pleuropnuemoniae apxIVA mutant was obtained based on an A. pleuropnuemoniae apxIIC-deleted mutant strain. An experimental infection assay was performed to evaluate the virulence of ApxIVA in piglets. Clinical signs, lung lesion scores, blood biochemical parameters and histopathologic changes in the piglets were recorded. The results indicated that the pathogenicity of A. pleuropnuemoniae was greater when ApxIVA was present, suggesting that ApxIVA is essential for expression of the full virulence of A. pleuropnuemoniae.
authors.affiliation: Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Jinlin
authors.initials: J
authors.lastname: Liu
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Chen
authors.initials: C
authors.lastname: Tan
authors.forename: Yi
authors.initials: Y
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Shulin
authors.initials: S
authors.lastname: Fu
authors.forename: Weicheng
authors.initials: W
authors.lastname: Bei
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
mesh_terms: D000189:Actinobacillus Infections / Q000382:microbiology / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae / Q000235:genetics* / Q000472:pathogenicity*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001786:Blood Glucose; D008168:Lung / Q000473:pathology; D051379:Mice; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000662:veterinary; D013552:Swine; D013997:Time Factors; D014774:Virulence
chemical_list: C122177:ApxIVA protein, Actinobacillus pleuropneumoniae; D001426:Bacterial Proteins; D001786:Blood Glucose; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase