title: Adherence of Actinobacillus pleuropneumoniae to swine-lung collagen.
abstract: Actinobacillus pleuropneumoniae serotype 1 adhered to immobilized swine-lung collagen. Bacteria bound to collagen type I, III, IV and V. At 5 min incubation, 30 % of bacteria adhered to collagen, reaching saturation in around 90 min. Treatment of bacteria with divalent-metal chelators diminished their attachment to collagen, and Ca(2+) but not Mg(2+) increased it, suggesting Ca(2+) dependence for adherence. Proteolytic enzymes drastically reduced bacterial adherence to collagen, showing that binding involved bacterial surface proteins. Porcine fibrinogen, haemoglobin and gelatin partially reduced collagen adhesion. A 60 kDa outer-membrane protein of A. pleuropneumoniae recognized the swine collagens by overlay. This membrane protein was apparently involved in adhesion to collagen and fibrinogen, but not to fibronectin and laminin. Antibodies against the 60 kDa protein inhibited the adhesion to collagen by 70 %, whereas pig convalescent-phase antibodies inhibited it by only 40 %. Serotypes 1 and 7 were the most adherent to pig collagen (taken as 100 %); serotypes 6 and 11 were the lowest (approximately 50 %), and neither showed the 60 kDa adhesin to biotinylated collagens. By negative staining, cells were observed initially to associate with collagen fibres in a polar manner, and the adhesin was detected on the bacterial surface. The results suggest that swine-lung collagen is an important target for A. pleuropneumoniae colonization and spreading, and that the attachment to this protein could play a relevant role in pathogenesis.
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Ap. 14-740, México, DF 07000, Mexico.
authors.forename: Idalia
authors.initials: I
authors.lastname: Enríquez-Verdugo
authors.affiliation: Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Blvd Universidad 940, Aguascalientes, Ags 20100, Mexico.
authors.forename: Alma L
authors.initials: AL
authors.lastname: Guerrero
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Ap. 14-740, México, DF 07000, Mexico.
authors.forename: J Jesús
authors.initials: JJ
authors.lastname: Serrano
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Ap. 14-740, México, DF 07000, Mexico.
authors.forename: Delfino
authors.initials: D
authors.lastname: Godínez
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN, Ap. 14-740, México, DF 07000, Mexico.
authors.forename: J Luis
authors.initials: JL
authors.lastname: Rosales
authors.affiliation: CENID-Microbiología, INIFAP, Carretera a Toluca Km 15.5, México, DF, Mexico.
authors.forename: Víctor
authors.initials: V
authors.lastname: Tenorio
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Ap. 14-740, México, DF 07000, Mexico.
authors.forename: Mireya
authors.initials: M
authors.lastname: de la Garza
mesh_terms: D016977:Actinobacillus pleuropneumoniae / Q000254:growth & development / Q000502:physiology*; D018829:Adhesins, Bacterial / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism*; D008168:Lung / Q000737:chemistry / Q000382:microbiology*; D013552:Swine / Q000382:microbiology*
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D024061:Collagen Type III