Salmonella enterica serovar Enteritidis biofilm lifestyle induces lower pathogenicity and reduces inflammatory response in a murine model compared to planktonic bacteria

Glycyrrhizin (GL), an important active ingredient of licorice root, which weakens the proinflammatory effects of high-mobility group box 1 (HMGB1) by blocking HMGB1 signaling. In this study, we investigated whether GL could suppress inflammation and carcinogenesis in an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced murine model of colorectal cancer. ICR mice were divided into four groups (n = 5, each)—control group, GL group, colon cancer (CC) group, and GL-treated CC (CC + GL) group, and sacrificed after 20 weeks. Plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α were measured using an enzyme-linked immunosorbent assay. The colonic tissue samples were immunohistochemically stained with DNA damage markers (8-nitroguanine and 8-oxo-7,8-dihydro-2′-deoxy-guanosine), inflammatory markers (COX-2 and HMGB1), and stem cell markers (YAP1 and SOX9). The average number of colonic tumors and the levels of IL-6 and TNF-α in the CC + GL group were significantly lower than those in the CC group. The levels of all inflammatory and cancer markers were significantly reduced in the CC + GL group. These results suggest that GL inhibits the inflammatory response by binding HMGB1, thereby inhibiting DNA damage and cancer stem cell proliferation and dedifferentiation. In conclusion, GL significantly attenuates the pathogenesis of AOM/DSS-induced colorectal cancer by inhibiting HMGB1-TLR4-NF-κB signaling.

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Identification of in vivo-induced genes during infection of chickens with Salmonella enterica serovar Enteritidis

Research in Veterinary Science ◽

10.1016/j.rvsc.2015.03.028 ◽

2015 ◽

Vol 100 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Shizhong Geng ◽

Zhicheng Liu ◽

Zhijie Lin ◽

Paul Barrow ◽

Zhiming Pan ◽

...

Keyword(s):

Salmonella Enterica ◽

Salmonella Enterica Serovar Enteritidis ◽

Induced Genes

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Naturally Occurring Motility-Defective Mutants of Salmonella enterica Serovar Enteritidis Isolated Preferentially from Nonhuman Rather than Human Sources

Applied and Environmental Microbiology ◽

10.1128/aem.05318-11 ◽

2011 ◽

Vol 77 (21) ◽

pp. 7740-7748 ◽

Cited By ~ 14

Author(s):

Lucía Yim ◽

Laura Betancor ◽

Arací Martínez ◽

Clare Bryant ◽

Duncan Maskell ◽

...

Keyword(s):

Salmonella Enterica ◽

Intestinal Epithelial ◽

Salmonella Enterica Serovar Enteritidis ◽

Transcriptional Responses ◽

Content Type ◽

Field Isolates ◽

Specific Pcr ◽

Human Intestinal Epithelial Cells ◽

Natural Isolates ◽

Cell Invasiveness

ABSTRACTSalmonellosis represents a worldwide health problem because it is one of the major causes of food-borne disease. Although motility is postulated as an importantSalmonellavirulence attribute, there is little information about variation in motility in natural isolates. Here we report the identification of a point mutation (T551 → G) inmotA, a gene essential for flagellar rotation, in severalSalmonella entericaserovar Enteritidis field isolates. This mutation results in bacteria that can biosynthesize structurally normal but paralyzed flagella and are impaired in their capacity to invade human intestinal epithelial cells. Introduction of a wild-type copy ofmotAinto one of these isolates restored both motility and cell invasiveness. ThemotAmutant triggered higher proinflammatory transcriptional responses than an aflagellate isolate in differentiated Caco-2 cells, suggesting that the paralyzed flagella are able to signal through pattern recognition receptors. A specific PCR was designed to screen for the T551 → G mutation in a collection of 266S. Enteritidis field isolates from a nationwide epidemic, comprising 194 from humans and 72 from other sources. We found that 72 of the 266 (27%) isolates were nonmotile, including 24.7% (48/194) of human and 33.3% (24/72) of food isolates. Among nonmotile isolates, 15 carried the T551 → G mutation and, significantly, 13 were recovered from food, including 7 from eggs, but only 2 were from human sources. These results suggest that the presence of paralyzed flagella may impair the ability ofS. Enteritidis to cause disease in the human host but does not prevent its ability to colonize chickens and infect eggs.

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Survival characteristics of Salmonella enterica serovar Enteritidis in chicken egg albumen

Epidemiology and Infection ◽

10.1017/s0950268806006054 ◽

2006 ◽

Vol 134 (5) ◽

pp. 967-976 ◽

Cited By ~ 44

Author(s):

H. KANG ◽

C. LOUI ◽

R. I. CLAVIJO ◽

L. W. RILEY ◽

S. LU

Keyword(s):

Salmonella Enterica ◽

Iron Acquisition ◽

Foodborne Pathogen ◽

Human Infection ◽

Salmonella Enterica Serovar Enteritidis ◽

Factors Affecting ◽

Chicken Egg ◽

Egg Albumen ◽

High Concentrations ◽

Incubation Temperatures

Salmonella enterica serovar Enteritidis (SE) is a major foodborne pathogen primarily causing human infection through contaminated chicken eggs. To understand how SE survives in chicken egg albumen, we systematically and quantitatively analysed the survival properties of SE in egg albumen and identified factors affecting its survival. Survival assays of SE in egg indicate that egg albumen restricted the growth of SE. A major factor that controlled SE's growth in egg albumen was iron restriction, since egg albumen supplemented with iron allowed SE to grow, and iron acquisition mutants of SE showed decreased survival in egg albumen. In addition, low pH of albumen, high concentrations of bacteria and low incubation temperatures of bacteria with albumen facilitates the survival of SE. Our results suggest that egg albumen uses multiple mechanisms to control SE including iron limitation, surface interaction and possible enzymatic activities.

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Cloning of Salmonella enterica Serovar Enteritidis Fimbrial Protein SefA as a Surface Protein in Escherichia coli Confers the Ability To Attach to Eukaryotic Cell Lines

Applied and Environmental Microbiology ◽

10.1128/aem.00639-09 ◽

2009 ◽

Vol 75 (20) ◽

pp. 6622-6625 ◽

Cited By ~ 6

Author(s):

Douglas L. Rank ◽

Mahdi A. Saeed ◽

Peter M. Muriana

Keyword(s):

Escherichia Coli ◽

Salmonella Enterica ◽

Expression Vector ◽

Surface Protein ◽

Surface Expression ◽

Eukaryotic Cell ◽

Salmonella Enterica Serovar Enteritidis ◽

Western Blot Assay ◽

E Coli ◽

Fimbrial Protein

ABSTRACT The gene for the Salmonella enterica serovar Enteritidis fimbrial protein SefA was cloned into an Escherichia coli surface expression vector and confirmed by Western blot assay. E. coli clones expressing SefA attached to avian ovary granulosa cells and HEp-2 cells, providing evidence for the involvement of SefA in the ability of Salmonella to attach to eukaryotic cells.

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