title: Biofilm formation and fibrinogen and fibronectin binding activities by Corynebacterium pseudodiphtheriticum invasive strains.
abstract: Biofilm-related infections are considered a major cause of morbidity and mortality in hospital environments. Biofilms allow microorganisms to exchange genetic material and to become persistent colonizers and/or multiresistant to antibiotics. Corynebacterium pseudodiphtheriticum (CPS), a commensal bacterium that colonizes skin and mucosal sites has become progressively multiresistant and responsible for severe nosocomial infections. However, virulence factors of this emergent pathogen remain unclear. Herein, we report the adhesive properties and biofilm formation on hydrophilic (glass) and hydrophobic (plastic) abiotic surfaces by CPS strains isolated from patients with localized (ATCC10700/Pharyngitis) and systemic (HHC1507/Bacteremia) infections. Adherence to polystyrene attributed to hydrophobic interactions between bacterial cells and this negatively charged surface indicated the involvement of cell surface hydrophobicity in the initial stage of biofilm formation. Attached microorganisms multiplied and formed microcolonies that accumulated as multilayered cell clusters, a step that involved intercellular adhesion and synthesis of extracellular matrix molecules. Further growth led to the formation of dense bacterial aggregates embedded in the exopolymeric matrix surrounded by voids, typical of mature biofilms. Data also showed CPS recognizing human fibrinogen (Fbg) and fibronectin (Fn) and involvement of these sera components in formation of "conditioning films". These findings suggested that biofilm formation may be associated with the expression of different adhesins. CPS may form biofilms in vivo possibly by an adherent biofilm mode of growth in vitro currently demonstrated on hydrophilic and hydrophobic abiotic surfaces. The affinity to Fbg and Fn and the biofilm-forming ability may contribute to the establishment and dissemination of infection caused by CPS.
authors.affiliation: Laboratório de Difteria e Corinebactérias de Importância Clínica (LDCIC), Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro (UERJ), Av. 28 de Setembro, 87 - Fundos, 3°andar, Vila Isabel, Rio de Janeiro, RJ, 20.551-030, Brazil.
authors.forename: Monica Cristina
authors.initials: MC
authors.lastname: Souza
authors.forename: Louisy Sanches
authors.initials: LS
authors.lastname: dos Santos
authors.forename: Leonardo Paiva
authors.initials: LP
authors.lastname: Sousa
authors.forename: Yuri Vieira
authors.initials: YV
authors.lastname: Faria
authors.forename: Juliana Nunes
authors.initials: JN
authors.lastname: Ramos
authors.forename: Priscila Soares
authors.initials: PS
authors.lastname: Sabbadini
authors.forename: Cíntia Silva
authors.initials: CS
authors.lastname: da Santos
authors.forename: Prescilla Emy
authors.initials: PE
authors.lastname: Nagao
authors.forename: Verônica Viana
authors.initials: VV
authors.lastname: Vieira
authors.forename: Débora Leandro Rama
authors.initials: DL
authors.lastname: Gomes
authors.forename: Raphael
authors.initials: R
authors.lastname: Hirata Júnior
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Mattos-Guaraldi
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D016470:Bacteremia / Q000382:microbiology; D001422:Bacterial Adhesion; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D003352:Corynebacterium / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D003354:Corynebacterium Infections / Q000382:microbiology; D004783:Environmental Microbiology; D005340:Fibrinogen / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D005898:Glass; D006801:Humans; D008853:Microscopy; D010612:Pharyngitis / Q000382:microbiology; D010969:Plastics
chemical_list: D018829:Adhesins, Bacterial; D005353:Fibronectins; D010969:Plastics; D005340:Fibrinogen