scholarly journals Fluoroquinolone treatment of experimental Salmonella enterica serovar Typhimurium DT104 infections in chickens selects for both gyrA mutations and changes in efflux pump gene expression

2005 ◽  
Vol 56 (2) ◽  
pp. 297-306 ◽  
Author(s):  
Luke P. Randall ◽  
Deborah J. Eaves ◽  
Sue W. Cooles ◽  
V. Ricci ◽  
Antony Buckley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Serovar Typhimurium

The effect of the Salmonella genomic island 1 on in vitro global gene expression in Salmonella enterica serovar Typhimurium LT2

2007 ◽  
Vol 9 (1) ◽  
pp. 21-27 ◽  
Author(s):  
George R. Golding ◽  
Adam B. Olson ◽  
Benoît Doublet ◽  
Axel Cloeckaert ◽  
Sara Christianson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Genomic Island ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Global Gene Expression ◽  
Serovar Typhimurium

scholarly journals Characterization and Differential Gene Expression between Two Phenotypic Phase Variants in Salmonella enterica Serovar Typhimurium

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e43592 ◽  
Author(s):  
Sheila K. Patterson ◽  
Klaudyna Borewicz ◽  
Timothy Johnson ◽  
Wayne Xu ◽  
Richard E. Isaacson
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Serovar Typhimurium ◽  
Differential Gene ◽  
Phase Variants

scholarly journals HilE Interacts with HilD and Negatively Regulates hilA Transcription and Expression of the Salmonella enterica Serovar Typhimurium Invasive Phenotype

2003 ◽  
Vol 71 (3) ◽  
pp. 1295-1305 ◽  
Author(s):  
M. Aaron Baxter ◽  
Thomas F. Fahlen ◽  
Rebecca L. Wilson ◽  
Bradley D. Jones
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Gastrointestinal Disease ◽  
Pathogenicity Island ◽  
Specific Gene ◽  
Negative Effects ◽  
Invasive Phenotype ◽  
Serovar Typhimurium ◽  
Two Hybrid

ABSTRACT The ability of Salmonella enterica serovar Typhimurium to traverse the intestinal mucosa of a host is an important step in its ability to initiate gastrointestinal disease. The majority of the genes required for this invasive characteristic are encoded on Salmonella pathogenicity island 1 (SPI1), and their expression is controlled by the transcriptional activator HilA, a member of the OmpR/ToxR family of proteins. A variety of genes (hilC, hilD, fis, sirA/barA, csrAB, phoB, fadD, envZ/ompR, fliZ, hilE, ams, lon, pag, and hha) have been identified that exert positive or negative effects on hilA expression, although the mechanisms by which these gene products function remain relatively unclear. Recent work indicates that the small DNA-binding protein, Hha, has a significant role in repressing hilA transcription and the invasive phenotype, particularly in response to osmolarity signals. We have characterized the Salmonella-specific gene, hilE, and found that it plays an important regulatory role in hilA transcription and invasion gene expression. Mutation of hilE causes derepression of hilA transcription, and overexpression of hilE superrepresses hilA expression and the invasive phenotype. Bacterial two-hybrid experiments indicate that the HilE protein interacts with HilD, suggesting a possible mechanism for HilE negative regulation of hilA gene expression and the Salmonella invasive phenotype. Finally, we have found that the hilE gene resides on a region of the serovar Typhimurium chromosome that has many characteristics of a pathogenicity island.

scholarly journals Tightly Regulated Gene Expression System in Salmonella enterica Serovar Typhimurium

2002 ◽  
Vol 184 (21) ◽  
pp. 6056-6059 ◽  
Author(s):  
Jeffrey McKinney ◽  
Cecilia Guerrier-Takada ◽  
Jorge Galán ◽  
Sidney Altman
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Expression System ◽  
Dynamic Control ◽  
Control Element ◽  
T7 Promoter ◽  
Serovar Typhimurium ◽  
Regulated Gene Expression ◽  
Rna Polymerase Gene

ABSTRACT A new Salmonella enterica serovar Typhimurium strain has been constructed to facilitate tightly regulated gene expression. Arabinose-inducible and glucose-repressible expression of a T7 RNA polymerase gene that has been integrated with an adjacent araC-PBAD control element into the bacterial chromosome allows dynamic control of T7 promoter-driven RNA transcription.

scholarly journals Role of FimW, FimY, and FimZ in Regulating the Expression of Type I Fimbriae in Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 191 (9) ◽  
pp. 3003-3010 ◽  
Author(s):  
Supreet Saini ◽  
Jeffrey A. Pearl ◽  
Christopher V. Rao
Keyword(s):  
Gene Expression ◽  
Negative Feedback ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Phase Variation ◽  
Type I ◽  
Serovar Typhimurium ◽  
Type I Fimbriae ◽  
Positive And Negative Feedback

ABSTRACT Type I fimbriae in Salmonella enterica serovar Typhimurium are surface appendages that facilitate binding to eukaryotic cells. Expression of the fim gene cluster is known to be regulated by three proteins—FimW, FimY, and FimZ—and a tRNA encoded by fimU. In this work, we investigated how these proteins and tRNA coordinately regulate fim gene expression. Our results indicate that FimY and FimZ independently activate the P fimA promoter which controls the expression of the fim structural genes. FimY and FimZ were also found to strongly activate each other's expression and weakly activate their own expression. FimW was found to negatively regulate fim gene expression by repressing transcription from the P fimY promoter, independent of FimY or FimZ. Moreover, FimW and FimY interact within a negative feedback loop, as FimY was found to activate the P fimW promoter. In the case of fimU, the expression of this gene was not found to be regulated by FimW, FimY, or FimZ. We also explored the effect of fim gene expression on Salmonella pathogenicity island 1 (SPI1). Our results indicate that FimZ alone is able to enhance the expression of hilE, a known repressor of SPI1 gene expression. Based on our results, we were able to propose an integrated model for the fim gene circuit. As this model involves a combination of positive and negative feedback, we hypothesized that the response of this circuit may be bistable and thus a possible mechanism for phase variation. However, we found that the response was continuous and not bistable.

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