title: Fibrinogen binds to nontoxigenic and toxigenic Corynebacterium diphtheriae strains.
abstract: The production of fibrinous exudates may play an important role in determining the outcome of bacterial infection. Although pseudomembrane formation is a characteristic feature of diphtheria, little is known about the fibrinogen (Fbn)-binding properties of Corynebacterium diphtheriae strains and the influence of the gene that codes for diphtheria toxin (tox gene) in this process. In this study we demonstrated the ability of C. diphtheriae strains to bind to Fbn and to convert Fbn to fibrin. Bacterial interaction with rabbit plasma was evaluated by both slide and tube tests. Interaction of microorganisms with human Fbn was evaluated by both enzyme linked immunosorbent assay (ELISA) and fluorescein isothiocyanate-conjugated (FITC) Fbn binding assays. Nontoxigenic and toxigenic strains formed bacterial aggregates in the presence of plasma in the slide tests. The ability to convert Fbn to a loose web of fibrin in the plasma solution in the tube tests appeared to be a common characteristic of the species, including strains that do not carry the tox gene. Fbn binding to C. diphtheriae strains occurred at varying intensities, as demonstrated by the FITC-Fbn and ELISA binding assays. Our data suggest that the capacity to bind to Fbn and to convert Fbn to fibrin may play a role in pseudomembrane formation and act as virulence determinants of both nontoxigenic and toxigenic strains.
authors.affiliation: Laboratório de Difteria e Corineformes de Importância Médica, Faculdade de Medicina, Universidade do Estado do Rio de Janeiro, 20551-030 Rio de Janeiro, Brasil.
authors.forename: Priscila Soares
authors.initials: PS
authors.lastname: Sabbadini
authors.forename: Marcia Rocha Novais
authors.initials: MR
authors.lastname: Genovez
authors.forename: Cecília Ferreira da
authors.initials: CF
authors.lastname: Silva
authors.forename: Thelma Lúcia Novaes
authors.initials: TL
authors.lastname: Adelino
authors.forename: Cintia Silva dos
authors.initials: CS
authors.lastname: Santos
authors.forename: Gabriela Andrade
authors.initials: GA
authors.lastname: Pereira
authors.forename: Prescilla Emy
authors.initials: PE
authors.lastname: Nagao
authors.forename: Alexandre Alves de Souza de Oliveira
authors.initials: AA
authors.lastname: Dias
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Mattos-Guaraldi
authors.forename: Raphael
authors.initials: R
authors.lastname: Hirata Júnior
mesh_terms: D000818:Animals; D003353:Corynebacterium diphtheriae / Q000235:genetics / Q000378:metabolism*; D004167:Diphtheria Toxin / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005340:Fibrinogen / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D011817:Rabbits; D014774:Virulence / Q000235:genetics
chemical_list: D004167:Diphtheria Toxin; D005340:Fibrinogen