INVESTIGADORES
MINAHK Carlos Javier
congresos y reuniones científicas
Título:
Stability of rcsc11 mutant of Salmonella Typhimurium under different growth conditions
Autor/es:
TORRES, MA; LECCESE TERRAF, MC; PESCARETTI, MM; MINAHK, C; DELGADO, MA
Lugar:
Mar del Plata
Reunión:
Congreso; LI Reunión Anual SAIB; 2015
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
Salmonella is a great prevalence pathogen in the population of Argentina. Its infection depends on the modulation of the pathogenicity islands genes expression, controlled by different regulatory systems. The RcsCDB system regulates the biosynthesis of colanic acid and flagella, and the virulence genes, between others. In the rcsC11 mutant the system is constitutively active, resulting in a mucoid phenotype and attenuated virulence. The aim of this study was to investigate the stability of the rcsC11 point mutation under different conditions that mimic the host environment, which was evaluated by the viability and reversion of mucoid phenotype. Our results demonstrated that, from all conditions tested, only the acid condition modified the rcsC11 mucoid phenotype. In addition, such reversion was observed after the fifth sub-culture at pH 4.5. To confirm the phenotype reversion, mucoid and "non mucoid" colonies were transduced with a chromosomal lacZ fusion to the RcsB-reporter flhC gene. Our results demonstrated that ?non mucoid? colonies displayed similar β-galactosidase activity levels than the wild type strain, supporting that the rcsC11 point mutation was reverted in all of them. Even so, our results suggest that the rcsC11 strain is an excellent candidate for the attenuate vaccines development, because the mucoid phenotype reversion was detected only in later stages of the assay