scholarly journals Sublethal Infection of C57BL/6 Mice with Salmonella enterica Serovar Typhimurium Leads to an Increase in Levels of Toll-Like Receptor 1 (TLR1), TLR2, and TLR9 mRNA as Well as a Decrease in Levels of TLR6 mRNA in Infected Organs

2005 ◽  
Vol 73 (3) ◽  
pp. 1873-1878 ◽  
Author(s):  
Sabine Tötemeyer ◽  
Pete Kaiser ◽  
Duncan J. Maskell ◽  
Clare E. Bryant
Keyword(s):  
Inflammatory Response ◽  
Mrna Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Signaling Molecules ◽  
Mrna Levels ◽  
Toll Like Receptor ◽  
Toll Like Receptors ◽  
Serovar Typhimurium ◽  
Strong Inflammatory Response

ABSTRACT Sublethal infection of C57BL/6 mice with Salmonella enterica serovar Typhimurium M525P initiates a strong inflammatory response. We measured organ expression of mRNA for Toll-like receptors and their associated signaling molecules during S. enterica serovar Typhimurium infection. During infection, the Toll-lie receptor 1 (TLR1), TLR2, and TLR9 mRNA levels increased, while TLR6 mRNA expression decreased.

scholarly journals Solitary Intestinal Lymphoid Tissue Provides a Productive Port of Entry for Salmonella enterica Serovar Typhimurium

2007 ◽  
Vol 75 (4) ◽  
pp. 1577-1585 ◽  
Author(s):  
Stephan Halle ◽  
Dirk Bumann ◽  
Heike Herbrand ◽  
Yvonne Willer ◽  
Sabrina Dähne ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Salmonella Enterica ◽  
Lymphoid Tissue ◽  
Salmonella Enterica Serovar Typhimurium ◽  
De Novo ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Serovar Typhimurium ◽  
Strong Inflammatory Response ◽  
Intestinal Lymphoid Tissue

ABSTRACT Oral infection of mice with Salmonella enterica serovar Typhimurium results in the colonization of Peyer's patches, triggering a vigorous inflammatory response and immunopathology at these sites. Here we demonstrate that in parallel to Peyer's patches a strong inflammatory response occurs in the intestine, resulting in the appearance of numerous inflammatory foci in the intestinal mucosa. These foci surround small lymphoid cell clusters termed solitary intestinal lymphoid tissue (SILT). Salmonella can be observed inside SILT at early stages of infection, and the number of infected structures matches the number of inflammatory foci arising at later time points. Infection leads to enlargement and morphological destruction of SILT but does not trigger de novo formation of lymphoid tissue. In conclusion, SILT, a lymphoid compartment mostly neglected in earlier studies, represents a major site for Salmonella invasion and ensuing mucosal pathology.

scholarly journals Toll-Like Receptor Expression in C3H/HeN and C3H/HeJ Mice during Salmonella enterica Serovar Typhimurium Infection

2003 ◽  
Vol 71 (11) ◽  
pp. 6653-6657 ◽  
Author(s):  
Sabine Tötemeyer ◽  
Neil Foster ◽  
Pete Kaiser ◽  
Duncan J. Maskell ◽  
Clare E. Bryant
Keyword(s):  
Mrna Expression ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Receptor Expression ◽  
Toll Like Receptor ◽  
Wild Type ◽  
Serovar Typhimurium ◽  
Toll Like Receptor 2

ABSTRACT Here, we have investigated the mRNA expression of Toll-like receptor 2 (TLR-2), TLR-4, and MD-2 in spleens and livers of C3H/HeN mice (carrying wild-type TLR-4) and C3H/HeJ mice (carrying mutated TLR-4) in response to Salmonella infection. During Salmonella infections, TLR-4 is activated, leading to increased TLR-2 and decreased TLR-4 expression.

scholarly journals Regulation of metE mRNA expression by FnrS small RNA in Salmonella enterica serovar Typhimurium

2019 ◽  
Vol 229 ◽  
pp. 126319
Author(s):  
Chia-Wei Chien ◽  
Yu-Feng Chan ◽  
Po-Shu Shih ◽  
Jung-En Kuan ◽  
Ke-Feng Wu ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Small Rna ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Serovar Typhimurium

scholarly journals Influence of Temperature and Predation on Survival of Salmonella enterica Serovar Typhimurium and Expression of invA in Soil and Manure-Amended Soil

2010 ◽  
Vol 76 (15) ◽  
pp. 5025-5031 ◽  
Author(s):  
R. Garc�a ◽  
J. B�lum ◽  
L. Fredslund ◽  
P. Santorum ◽  
C. S. Jacobsen
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Mrna Levels ◽  
Predator Prey ◽  
Fast Decrease ◽  
Serovar Typhimurium ◽  
Prey Interaction ◽  
Rna And Dna ◽  
Amended Soil

ABSTRACT The effects of three temperatures (5, 15, and 25�C) on the survival of Salmonella enterica serovar Typhimurium in topsoil were investigated in small microcosms by three different techniques: plate counting, invA gene quantification, and invA mRNA quantification. Differences in survival were related to the effect of protozoan predation. Tetracycline-resistant Salmonella serovar Typhimurium was inoculated into soil and manure-amended soil at 1.5 � 108 cells g soil−1. Population densities were determined by plate counting and by molecular methods and monitored for 42 days. Simultaneous extraction of RNA and DNA, followed by quantitative PCR, was used to investigate invA gene levels and expression. Analysis by these three techniques showed that Salmonella serovar Typhimurium survived better at 5�C. Comparing DNA and CFU levels, significantly higher values were determined by DNA-based techniques. invA mRNA levels showed a fast decrease in activity, with no detectable mRNA after an incubation period of less than 4 days in any of the soil scenarios. A negative correlation was found between Salmonella serovar Typhimurium CFU levels and protozoan most probable numbers, and we propose the role of the predator-prey interaction as a factor to explain the die-off of the introduced strain by both culture- and DNA quantification-based methods. The results indicate that temperature, manure, and protozoan predation are important factors influencing the survival of Salmonella serovar Typhimurium in soil.

scholarly journals A Salmonella enterica Serovar Typhimurium hemA Mutant Is Highly Susceptible to Oxidative DNA Damage

2002 ◽  
Vol 184 (14) ◽  
pp. 3774-3784 ◽  
Author(s):  
Maya Elgrably-Weiss ◽  
Sunny Park ◽  
Eliana Schlosser-Silverman ◽  
Ilan Rosenshine ◽  
James Imlay ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Salmonella Enterica ◽  
Fenton Reaction ◽  
Oxidative Dna Damage ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Intracellular Iron ◽  
Serovar Typhimurium

ABSTRACT The first committed step in the biosynthesis of heme, an important cofactor of two catalases and a number of cytochromes, is catalyzed by the hemA gene product. Salmonella enterica serovar Typhimurium hemA26::Tn10d (hemA26) was identified in a genetic screen of insertion mutants that were sensitive to hydrogen peroxide. Here we show that the hemA26 mutant respires at half the rate of wild-type cells and is highly susceptible to the effects of oxygen species. Exposure of the hemA26 strain to hydrogen peroxide results in extensive DNA damage and cell death. The chelation of intracellular free iron fully abrogates the sensitivity of this mutant, indicating that the DNA damage results from the iron-catalyzed formation of hydroxyl radicals. The inactivation of heme synthesis does not change the amount of intracellular iron, but by diminishing the rate of respiration, it apparently increases the amount of reducing equivalents available to drive the Fenton reaction. We also report that hydrogen peroxide has opposite effects on the expression of hemA and hemH, the first and last genes of heme biosynthesis pathway, respectively. hemA mRNA levels decrease, while the transcription of hemH is induced by hydrogen peroxide, in an oxyR-dependent manner. The oxyR-dependent induction is suppressed under conditions that accelerate the Fenton reaction by a mechanism that is not yet understood.

scholarly journals Induction of a Novel Chicken Toll-Like Receptor following Salmonella enterica Serovar Typhimurium Infection

2006 ◽  
Vol 74 (3) ◽  
pp. 1692-1698 ◽  
Author(s):  
Rowan Higgs ◽  
Paul Cormican ◽  
Sarah Cahalane ◽  
Brenda Allan ◽  
Andrew T. Lloyd ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Bioinformatic Analysis ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Tlr2 Expression ◽  
Embryonic Fibroblasts ◽  
Serovar Typhimurium

ABSTRACT Toll-like receptors (TLRs) are a group of highly conserved molecules that initiate the innate immune response to pathogens by recognizing structural motifs expressed by microbes. We have identified a novel TLR, TLR15, by bioinformatic analysis of the chicken genome, which is distinct from any known vertebrate TLR and thus appears to be avian specific. The gene for TLR15 was sequenced and is found on chromosome 3, and it has archetypal TIR and transmembrane domains and a distinctive arrangement of extracellular leucine-rich regions. mRNA for TLR15 was detected in the spleen, bursa, and bone marrow of healthy chickens, suggesting a role for this novel receptor in constitutive host defense. Following in vivo Salmonella enterica serovar Typhimurium infection, quantitative real-time PCR demonstrated significant upregulation of TLR15 in the cecum of infected chickens. Interestingly, similar induction of TLR2 expression following infection was also observed. In vitro studies revealed TLR15 upregulation in chicken embryonic fibroblasts stimulated with heat-killed S. enterica serovar Typhimurium. Collectively, these results suggest a role for the TLR in avian defense against bacterial infection. We hypothesize that TLR15 may represent an avian-specific TLR that has been either retained in chicken and lost in other taxa or gained in the chicken.

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