CIVETAN   23983
CENTRO DE INVESTIGACION VETERINARIA DE TANDIL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Biofilms are defined as complex communities of microorganisms that grow embedded in an organic polymer matrix produced by themselves and adhered to an organic or inorganic surface. They are a way of survival and persistence in the environment offering adv
Autor/es:
PADOLA, NORA LÍA; MONTERO, DAVID; ETCHEVERRÍA, ANALÍA I.; VÉLEZ, VICTORIA; VIDAL, ROBERTO; COLELLO, ROCÍO
Lugar:
Florencia
Reunión:
Simposio; 10 th International Symposium on Shiga Toxin Producing Escherichia coli infections; 2018
Resumen:
Shiga toxin-producing Escherichia coli (STEC) are animportant cause of foodborne illnesses worldwide. STECstrains can attach to different surface by using some adhesins.One of them is the curli fimbriae involved in biofilmformation. Locus of Adhesion and Autoaggregation (LAA) is anovel pathogenicity island carrying genes that could beinvolved in adhesion and biofilm formation. STEC formbiofilms in different environments, which can contaminatefood and generate infections, while protecting themselvesagainst adverse conditions such as the use of disinfectantsTwo O91 strains were used, one of them is a native strain isolated frombovine and the other was a mutant with LAA deleted (named ∆LAA). Theassay for quantification of biofilm formation was performed in 96-wellpolystyrene microtiter. Each test was performed in triplicate and in threeseparate experiments to 37°C for 72 h. The strains were grown in LBbroth at 37°C for 18 h. During biofilm formation 0.1 ml was inoculatedonto Congo Red (CR) plates at different times (0, 6, 20 h) and incubatedfor 48 h at 28°C. Curli-expressing strains showed red colonies and noncurli-expressingstrains displayed white colonies.A- The two strains were classified as strong biofilm formers,but in O91 ∆LAA the biofilm formation was reduced.B- In strain O91 ∆LAA the expression of curli fimbriae wasuniform during the biofirm formation, while in O91 nativethe expression was register to 6 hour of the biofilm formationand then curli was not expressed. Biofilm formation could be affected in a complex way by both physiological and environmentalfactors. In this case the absence of LAA reduces STEC capacity to produce biofilm and it could beregulated by interaction of curli and other genes codified by LAA.