title: Role of bacteriophages in STEC infections: new implications for the design of prophylactic and treatment approaches.
abstract: Shiga toxin (Stx) is considered the main virulence factor in Shiga toxin-producing Escherichia coli (STEC) infections. Previously we reported the expression of biologically active Stx by eukaryotic cells in vitro and in vivo following transfection with plasmids encoding Stx under control of the native bacterial promoter (1,2). Since stx genes are present in the genome of lysogenic bacteriophages, here we evaluated the relevance of bacteriophages during STEC infection. We used the non-pathogenic E. coli C600 strain carrying a lysogenic 933W mutant bacteriophage in which the stx operon was replaced by a gene encoding the green fluorescent protein (GFP). Tracking GFP expression using an In Vivo Imaging System (IVIS), we detected fluorescence in liver, kidney, and intestine of mice infected with the recombinant E. coli strain after treatment with ciprofloxacin, which induces the lytic replication and release of bacteriophages. In addition, we showed that chitosan, a linear polysaccharide composed of d-glucosamine residues and with a number of commercial and biomedical uses, had strong anti-bacteriophage effects, as demonstrated at in vitro and in vivo conditions. These findings bring promising perspectives for the prevention and treatment of haemolytic uremic syndrome (HUS) cases.
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-060, Brazil.
authors.forename: Jaime H
authors.initials: JH
authors.lastname: Amorim
authors.affiliation: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Universidad Nacional de Quilmes, Buenos Aires, 1876, Argentina.
authors.forename: Manuel E
authors.initials: ME
authors.lastname: Del Cogliano
authors.affiliation: Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental (IMEX) (CONICET), Academia Nacional de Medicina, Buenos Aires, 1425, Argentina.
authors.forename: Romina J
authors.initials: RJ
authors.lastname: Fernandez-Brando
authors.affiliation: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Universidad Nacional de Quilmes, Buenos Aires, 1876, Argentina.
authors.forename: Marcos F
authors.initials: MF
authors.lastname: Bilen
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-060, Brazil.
authors.forename: Monica R
authors.initials: MR
authors.lastname: Jesus
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-060, Brazil.
authors.forename: Wilson B
authors.initials: WB
authors.lastname: Luiz
authors.affiliation: Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental (IMEX) (CONICET), Academia Nacional de Medicina, Buenos Aires, 1425, Argentina.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Palermo
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-060, Brazil.
authors.forename: Rita C C
authors.initials: RC
authors.lastname: Ferreira
authors.affiliation: BioSur, Ciudad Autónoma de Buenos Aires, Buenos Aires, 1406, Argentina.
authors.forename: Esteban G
authors.initials: EG
authors.lastname: Servat
authors.affiliation: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Universidad Nacional de Quilmes, Buenos Aires, 1876, Argentina.
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Ghiringhelli
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-060, Brazil.
authors.forename: Luis C S
authors.initials: LC
authors.lastname: Ferreira
authors.affiliation: Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Universidad Nacional de Quilmes, Buenos Aires, 1876, Argentina.
authors.forename: Leticia V
authors.initials: LV
authors.lastname: Bentancor