IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Salmonella-specific transcriptional regulators involved in biofilm formation and virulence
Autor/es:
FIGUEROA, M.R.; HUMBERT, M.V.; CHECA, S.K.; SONCINI, F.C.
Lugar:
Córdoba
Reunión:
Congreso; XI Congreso Argentino de Microbiología General; 2015
Institución organizadora:
SAMIGE
Resumen:
Salmonellosis is among the most common foodborne diseases, with millions of human cases occurring worldwide every year. One of the key aspects of Salmonella?s life cycle that contributes to its high prevalence is its ability to form biofilms. This multicellular behavior allows the pathogen to survive hostile environmental conditions, and confers resistance to both host defenses and antimicrobial agents. Such resilience against extreme challenges is provided by means of a self-produced extracellular matrix which also contributes to attachment of sessile bacteria to each other and to both biotic and abiotic surfaces. Cellulose and curli fimbriae are major constituents of the Salmonella extracellular matrix. Expression of their biosynthetic genes is controlled at the transcriptional level by the master regulator CsgD. This transcriptional activator is in turn finely tuned by several transcription factors that integrate different environmental cues. We identified new Salmonella-specific transcription factors that participate in the control of biofilm-formation of this enteric bacterium. Deletion, as well as overexpression of the genes coding for these factors in different genetic backgrounds markedly affected motility, resistance to antibiotics and modified the development of characteristic biofilm morphotypes of this species. We showed that these factors affect production of cellulose and expression of csgD through different mechanisms. These results indicate that these Salmonella-specific transcription factors trigger biofilm formation, and hence control the switch between planktonic and sessile lifestyles