scholarly journals SiiE Is Secreted by the Salmonella enterica Serovar Typhimurium Pathogenicity Island 4-Encoded Secretion System and Contributes to Intestinal Colonization in Cattle

2007 ◽  
Vol 75 (3) ◽  
pp. 1524-1533 ◽  
Author(s):  
Eirwen Morgan ◽  
Alison J. Bowen ◽  
Sonya C. Carnell ◽  
Timothy S. Wallis ◽  
Mark P. Stevens
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Type I ◽  
Intestinal Colonization ◽  
Serovar Typhimurium

ABSTRACT Here we report that Salmonella enterica serovar Typhimurium pathogenicity island 4 carries a type I secretion system (siiCDF) which secretes an ∼600-kDa protein (encoded by siiE). SiiE is surface expressed, and its production is regulated by HilA. SiiE and SiiF influence colonization in cattle and the invasion of bovine enterocytes.

scholarly journals Secretion of the orgC Gene Product by Salmonella enterica Serovar Typhimurium

2003 ◽  
Vol 71 (11) ◽  
pp. 6680-6685 ◽  
Author(s):  
James B. Day ◽  
Catherine A. Lee
Keyword(s):  
Gene Product ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Type Iii Secretion System ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Serovar Typhimurium ◽  
Transposon Insertions

ABSTRACT HilA activates the transcription of genes on Salmonella pathogenicity island 1 (SPI1), which encodes a type III secretion system (TTSS). Previous studies showed that transposon insertions in orgC, a gene located on SPI1, increase hilA expression. We characterize the orgC gene product and show that it is secreted via the SPI1 TTSS. We propose a model whereby OrgC functions as a secreted repressor of the SPI1 virulence genes.

scholarly journals Coordinate Regulation of Salmonella Pathogenicity Island 1 (SPI1) and SPI4 in Salmonella enterica Serovar Typhimurium

2007 ◽  
Vol 76 (3) ◽  
pp. 1024-1035 ◽  
Author(s):  
Kara L. Main-Hester ◽  
Katherine M. Colpitts ◽  
Gracie A. Thomas ◽  
Ferric C. Fang ◽  
Stephen J. Libby
Keyword(s):  
Mutant Strain ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Pathogenicity Island ◽  
Open Reading Frames ◽  
Type I ◽  
Coordinate Regulation ◽  
Serovar Typhimurium ◽  
Epithelial Invasion ◽  
Secretory System

ABSTRACT Salmonella enterica serovar Typhimurium harbors five pathogenicity islands (SPI) required for infection in vertebrate hosts. Although the role of SPI1 in promoting epithelial invasion and proinflammatory cell death has been amply documented, SPI4 has only more recently been implicated in Salmonella virulence. SPI4 is a 24-kb pathogenicity island containing six open reading frames, siiA to siiF. Secretion of the 595-kDa SiiE protein requires a type I secretory system encoded by siiC, siiD, and siiF. An operon polarity suppressor (ops) sequence within the 5′ untranslated region upstream of siiA is required for optimal SPI4 expression and predicted to bind the antiterminator RfaH. SiiE concentrations are decreased in a SPI1 mutant strain, suggesting that SPI1 and SPI4 may have common regulatory inputs. SPI1 gene expression is positively regulated by the transcriptional activators HilA, HilC, and HilD, encoded within SPI1, and negatively regulated by the regulators HilE and PhoP. Here, we show that mutations in hilA, hilC, or hilD similarly reduce expression of siiE, and mutations in hilE or phoP enhance siiE expression. Individual overexpression of HilA, HilC, or HilD in the absence of SPI1 cannot activate siiE expression, suggesting that these transcriptional regulators act in concert or in combination with additional SPI1-encoded regulatory loci to activate SPI4. HilA is no longer required for siiE expression in an hns mutant strain, suggesting that HilA promotes SPI4 expression by antagonizing the global transcriptional silencer H-NS. Coordinate regulation suggests that SPI1 and SPI4 play complementary roles in the interaction of S. enterica serovar Typhimurium with the host intestinal mucosa.

scholarly journals Delineation of the Salmonella enterica Serovar Typhimurium HilA Regulon through Genome-Wide Location and Transcript Analysis

2007 ◽  
Vol 189 (13) ◽  
pp. 4587-4596 ◽  
Author(s):  
Inge M. V. Thijs ◽  
Sigrid C. J. De Keersmaecker ◽  
Abeer Fadda ◽  
Kristof Engelen ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Effector Proteins ◽  
Transcript Analysis ◽  
Genome Wide ◽  
Serovar Typhimurium ◽  
Genes Encoding

ABSTRACT The Salmonella enterica serovar Typhimurium HilA protein is the key regulator for the invasion of epithelial cells. By a combination of genome-wide location and transcript analysis, the HilA-dependent regulon has been delineated. Under invasion-inducing conditions, HilA binds to most of the known target genes and a number of new target genes. The sopB, sopE, and sopA genes, encoding effector proteins secreted by the type III secretion system on Salmonella pathogenicity island 1 (SPI-1), were identified as being both bound by HilA and differentially regulated in an HilA mutant. This suggests a cooperative role for HilA and InvF in the regulation of SPI-1-secreted effectors. Also, siiA, the first gene of SPI-4, is both bound by HilA and differentially regulated in an HilA mutant, thus linking this pathogenicity island to the invasion key regulator. Finally, the interactions of HilA with the SPI-2 secretion system gene ssaH and the flagellar gene flhD imply a repressor function for HilA under invasion-inducing conditions.

scholarly journals The Salmonella Pathogenicity Island 2-Encoded Type III Secretion System Is Essential for the Survival of Salmonella enterica Serovar Typhimurium in Free-Living Amoebae

2009 ◽  
Vol 75 (6) ◽  
pp. 1793-1795 ◽  
Author(s):  
Benjamin Bleasdale ◽  
Penelope J. Lott ◽  
Aparna Jagannathan ◽  
Mark P. Stevens ◽  
Richard J. Birtles ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Type Iii Secretion System ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Free Living ◽  
Type Iii ◽  
Serovar Typhimurium ◽  
Potential Reservoir

ABSTRACT Free-living amoebae represent a potential reservoir and predator of Salmonella enterica. Through the use of type III secretion system (T3SS) mutants and analysis of transcription of selected T3SS genes, we demonstrated that the Salmonella pathogenicity island 2 is highly induced during S. enterica serovar Typhimurium infection of Acanthamoeba polyphaga and is essential for survival within amoebae.

Safety and immunogenicity of attenuated Salmonella enterica serovar Typhimurium delivering an HIV-1 Gag antigen via the Salmonella Type III secretion system

Vaccine ◽  
2006 ◽  
Vol 24 (37-39) ◽  
pp. 6216-6224 ◽  
Author(s):  
Camille N. Kotton ◽  
Alexander J. Lankowski ◽  
Nathaniel Scott ◽  
David Sisul ◽  
Li Mei Chen ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Iii ◽  
Serovar Typhimurium ◽  
Hiv 1
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