title: Effect of antibiotics on cellular stress generated in Shiga toxin-producing Escherichia coli O157:H7 and non-O157 biofilms.
abstract: Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens, with the main virulence factor of this bacterium being its capacity to secrete Shiga toxins (Stxs). Therefore, the use of certain antibiotics for the treatment of this infection, which induces the liberation of Stxs, is controversial. Reactive oxygen and nitrogen species are also involved in the pathogenesis of different diseases. The purpose of this study was to analyze the effects of antibiotics on biofilms of STEC and the relationships between cellular stress and the release of Stx. To this end, biofilms of reference and clinical strains were treated with antibiotics (ciprofloxacin, fosfomycin and rifaximin) and the production of oxidants, the antioxidant defense system and toxin release were evaluated. Ciprofloxacin altered the prooxidant-antioxidant balance, with a decrease of oxidant metabolites and an increase of superoxide dismutase and catalase activity, being associated with high-levels of Stx production. Furthermore, inhibition of oxidative stress by exogenous antioxidants was correlated with a reduction in the liberation of Stx, indicating the participation of this phenomenon in the release of this toxin. In contrast, fosfomycin and rifaximin produced less alteration with a minimal production of Stx. Our data show that treatment of biofilm-STEC with these antibiotics induces oxidative stress-mediated release of Stx.
authors.affiliation: IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Angel Villegas
authors.affiliation: IMBIV-CONICET y Cátedra de Microbiología, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina.
authors.forename: José
authors.initials: J
authors.lastname: Baronetti
authors.affiliation: IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
authors.forename: Inés
authors.initials: I
authors.lastname: Albesa
authors.affiliation: Laboratorio de Inmunoquímica y Biotecnología, Dpto. SAMP, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.
authors.forename: Analía
authors.initials: A
authors.lastname: Etcheverría
authors.affiliation: IMBIV-CONICET y Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
authors.forename: M Cecilia
authors.initials: MC
authors.lastname: Becerra
authors.affiliation: Laboratorio de Inmunoquímica y Biotecnología, Dpto. SAMP, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.
authors.forename: Nora L
authors.initials: NL
authors.lastname: Padola
authors.affiliation: IMBIV-CONICET y Cátedra de Microbiología, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Argentina. Electronic address: gabrielaparaje@gmail.com.
authors.forename: M Gabriela
authors.initials: MG
authors.lastname: Paraje
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D018441:Biofilms; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D002939:Ciprofloxacin / Q000494:pharmacology; D005578:Fosfomycin / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D012294:Rifamycins / Q000494:pharmacology; D000078262:Rifaximin; D022622:Shiga Toxin 1 / Q000378:metabolism*; D022641:Shiga Toxin 2 / Q000378:metabolism*; D054323:Shiga-Toxigenic Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013482:Superoxide Dismutase / Q000378:metabolism; D014709:Vero Cells; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D017382:Reactive Oxygen Species; D012294:Rifamycins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D037521:Virulence Factors; D005578:Fosfomycin; D009569:Nitric Oxide; D002939:Ciprofloxacin; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D000078262:Rifaximin; D001205:Ascorbic Acid
keywords: Antibiotic; Biofilms; Ciprofloxacin; Escherichia coli O157:H7; Fosfomycin; Hemolytic uremic syndrome (HUS); Rifaximin; Shiga toxin (Stx)