INVESTIGADORES
GIACOMODONATO Monica Nancy
congresos y reuniones científicas
Título:
Expression of SopD effector in a murine model of Salmonella Typhimurium infection
Autor/es:
GIACOMODONATO MN, UZZAU S, SARNACKI SH, RUBINO S, CERQUETTI MC
Lugar:
Atlanta, USA
Reunión:
Congreso; 105th General Meeting of American Society for Microbiology; 2005
Institución organizadora:
American Society for Microbiology
Resumen:
SopD is an effector protein of Salmonella Typhimurium that plays a major role in promoting enteropathogenesis.  Recently it was suggested that SopD contributes to virulence during systemic infection of the host.  The aim of this study was to determine the expression of SopD at late stages of murine salmonellosis, in vivo.  S. Typhimurium SSM3214 sopD::3xFLAG sipA::3xFLAG cat::FLAG was used throughout the experiments.  The expression of effector proteins SipA and SopD was determined in vitro, analysing different fractions of bacterial cultures and in vivo using a lethal model of S. typhimurium infection.  Bacterial culture supernatants and pellets were used to investigate secreted-proteins and cell-associated proteins, respectively.  Expression was analysed by SDS-page and immunoblotting  with anti-FLAG antibodies.  SipA and SopD were found in secreted as well as in pelleted protein fractions.  For the in vivo experiments, six to eight week-old Balb/c mice were inoculated intraperitoneally with a lethal dose of 5 x 103 cfu of S. Typhimurium SSM3214. Mice were sacrificed at different time after infection; spleens were removed aseptically and ground through a stainless mesh.  Homogenates were resuspended in 1.5 ml of iced distilled water and processed for the recovery of bacteria to be subjected to Western blot analysis.  Seventy-two hours after bacterial inoculation SSM3214 strain was recovered from the spleens [median: (1 x 106 cfu/animal); range: 5 x 105 - 3 x 106 cfu/animal].  Analysis of bacterial proteins revealed that SopD (but not SipA) was expressed in vivo at 48 and 72 hs post infection.  These results demonstrate the in vivo expression of SopD protein in S. Typhimurium recovered from spleen during the late stage of murine salmonellosis.