Characterization of Salmonella type III secretion hyper-activity which results in biofilm-like cell aggregation.

摘要: We have previously reported the cloning of Salmonella enterica serovar Typhimurium SPI-1 secretion system and use this clone to functionally complement a ΔSPI-1 strain for type III activity. In current study, we discovered that S. cultures containing cloned display an adherent biofilm cell clumps in media. This phenotype was associated with hyper-expression functions. The were copious amounts secreted protein substrates SipA, SipB, SipC, SopB, SopE, SptP. used C-terminally FLAG-tagged SipA further demonstrate substrate association aggregates using fluorescence microscopy immunogold electron microscopy. Different backgrounds both flagellated nonflagellated strains displayed phenotype. Mutations genes essential known bacterial pathways (bcsA, csgBA, bapA) did not affect biofilms formed here indicating phenomenon is independent established mechanisms. SPI-1-mediated able massively recruit heterologous non-biofilm forming bacteria into community. results indicate aggregation mediated by elevated activity applications engineered formation, purification strategies, antigen display.