title: Genotypic characterization and biofilm formation of Shiga toxin-producing Escherichia coli.
abstract: Shiga toxin-producing Escherichia coli (STEC) are recognized as one of the most dangerous foodborne pathogens. The production of Shiga toxins together with intimin protein is among the main virulence factors. However, the ability to form biofilm can protect bacteria against environmental factors (i.e. desiccation, exposure to UV rays, predation, etc.) and sanitization procedures (cleaning, rinsing, chlorination), increasing their survival on food products and in manufacturing plants. Forty-five isolates collected from food and fecal samples were genotyped by pulsed field gel electrophoresis analysis with XbaI restriction enzyme and investigated by searching for toxins (stx1, stx2) and intimin (eae) genes and serogroup (O157, O26, O145, O111, O103 and O104). Afterward, the ability to develop biofilm in microtiter assay and the production of adhesive curli fimbriae and cellulose on agar plates were tested. Our study demonstrated that biofilm formation has a great variability among STEC strains and cannot be related to a specific pulsotype nor even to serogroup or presence of virulence genes.
authors.forename: Claudia
authors.initials: C
authors.lastname: Picozzi
authors.forename: Davide
authors.initials: D
authors.lastname: Antoniani
authors.forename: Ileana
authors.initials: I
authors.lastname: Vigentini
authors.forename: Roberto
authors.initials: R
authors.lastname: Foschino
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kneifel
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D002482:Cellulose / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D005838:Genotype; D006801:Humans; D058889:Molecular Typing; D065288:Serogroup; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli; C077481:Crl protein, Bacteria; D002482:Cellulose
keywords: Shiga-toxin producing Escherichia coli; biofilm formation; fecal isolates; goat milk; pulsed field gel electrophoresis; virulence factors