title: Flagellin and GroEL mediates in vitro binding of an atypical enteropathogenic Escherichia coli to cellular fibronectin.
abstract: BACKGROUND
  Enteropathogenic Escherichia coli (EPEC) is distinguished mainly by the presence of EPEC adherence factor plasmid (pEAF) in typical EPEC (tEPEC) and its absence in atypical EPEC (aEPEC). The initial adherence to the intestinal mucosa is complex and mediated by adhesins other than bundle-forming pilus, which is not produced by aEPEC. Extracellular matrix (ECM) proteins of eukaryotic cells are commonly recognized by bacterial adhesins. Therefore, binding to ECM proteins may facilitate colonization, invasion and/or signaling by intestinal pathogens. Previous studies from our group demonstrated that aEPEC O26:H11 (strain BA2103) showed high binding activity to fibronectin, not shared by its counterpart, aEPEC O26:HNM.
  
  
  RESULTS
  In the present study, using mass spectrometry after fibronectin-associated immunoprecipitation, two proteins, flagellin (50 kDa) and GroEL (52 kDa), were identified and BA2103 binding ability to fibronectin was inhibited in the presence of anti-H11 and anti-GroEL sera, but not by either naïve rabbit or other unrelated sera. It was also observed that the presence of purified flagellin inhibits adhesion of BA2103 to cellular fibronectin in a dose-dependent manner. Additionally, BA2103 GroEL is similar to the same protein of uropathogenic E. coli.
  
  
  CONCLUSIONS
  Our results suggest that flagellin may play a role in the in vitro interaction of BA2103 with cellular fibronectin, and GroEL can be an accessory protein in this process.
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Claudia T P
authors.initials: CT
authors.lastname: Moraes
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Polatto
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Sarita S
authors.initials: SS
authors.lastname: Rossato
authors.affiliation: Centro de Estudios Moleculares, Departamento de Pediatría, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile.
authors.forename: Mariana
authors.initials: M
authors.lastname: Izquierdo
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Danielle D
authors.initials: DD
authors.lastname: Munhoz
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Fernando H
authors.initials: FH
authors.lastname: Martins
authors.affiliation: Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Pimenta
authors.affiliation: Centro de Estudios Moleculares, Departamento de Pediatría, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile.
authors.forename: Mauricio J
authors.initials: MJ
authors.lastname: Farfan
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Waldir P
authors.initials: WP
authors.lastname: Elias
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil.
authors.forename: Ângela S
authors.initials: ÂS
authors.lastname: Barbosa
authors.affiliation: Laboratório de Bacteriologia, Instituto Butantan, Av. Vital Brazil, 1500 - 05503-900, São Paulo, SP, Brazil. roxane@butantan.gov.br.
authors.forename: Roxane M F
authors.initials: RM
authors.lastname: Piazza
mesh_terms: D001422:Bacterial Adhesion; D018834:Chaperonin 60 / Q000378:metabolism*; D054308:Enteropathogenic Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D005408:Flagellin; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D013058:Mass Spectrometry
chemical_list: D018834:Chaperonin 60; D029968:Escherichia coli Proteins; D005353:Fibronectins; C516095:FliC protein, E coli; D005408:Flagellin