title: Secreted proteins of Avibacterium paragallinarum are lethal for chicken embryo.
abstract: Avibacterium paragallinarum causes infectious coryza in chickens. This bacterium secretes proteins of 110 kDa (a putative RTX protein) and 120 kDa. Expression of these proteins increases by the addition of CaCl(2), MgSO(4), MnSO(4), or ferric ammonium citrate and diminishes with CuSO(4) or ZnCl(2). Protein expression is optimal at 37 degrees C and pH 7.5. Mortality (90-100%) of chicken embryos was observed when secreted proteins (SPs) from A. paragallinarum reference or field isolates (serogroup A or C) were inoculated via yolk sac and was not observed when SPs from A. avium, a chicken respiratory tract indigenous bacterium, were inoculated. A. paragallinarum SPs could contain toxins responsible for the embryo deaths. Indeed, presence of the putative RTX protein of 110 kDa was confirmed by Western blotting with antibodies against the Actinobacillus pleuropneumoniae RTX ApxI, a closely related RTX protein.
authors.affiliation: BIOVETSA de CV, Tehuacán, Puebla, México.
authors.forename: Víctor
authors.initials: V
authors.lastname: Pérez-Márquez
authors.forename: Alma
authors.initials: A
authors.lastname: Pérez-Méndez
authors.forename: Jorge
authors.initials: J
authors.lastname: Ibarra-Caballero
authors.forename: Gabriela
authors.initials: G
authors.lastname: Gómez-Lugo
authors.forename: Candelario
authors.initials: C
authors.lastname: Vázquez-Cruz
authors.forename: Sergio
authors.initials: S
authors.lastname: Vaca
authors.forename: Erasmo
authors.initials: E
authors.lastname: Negrete-Abascal
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D002642:Chick Embryo; D004591:Electrophoresis, Polyacrylamide Gel
chemical_list: D001426:Bacterial Proteins