Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat bacterial infections. We associated/challenged one-week-old gnotobiotic piglets with wild-type S. Typhimurium with S chemotype or its isogenic ∆rfa mutants with R chemotype LPS. The wild-type S. Typhimurium induced TLR2 and TLR4 mRNA expression but not TLR9 mRNA expression in the ileum and colon of one-week-old gnotobiotic piglets 24 h after challenge. The TLR2 and TLR4 stimulatory effects of the S. Typhimurium ∆rfa mutants were related to the completeness of their LPS chain. The transcription of IL-12/23 p40, IFN-γ, and IL-6 in the intestine and the intestinal and plasmatic levels of IL-12/23 p40 and IL-6 but not IFN-γ were related to the activation of TLR2 and TLR4 signaling pathways. The avirulent S. Typhimurium ∆rfa mutants are potentially useful for modulation of the TLR2 and TLR4 signaling pathways to protect the immunocompromised gnotobiotic piglets against subsequent infection with the virulent S. Typhimurium.

• Klíčová slova
• Salmonella Typhimurium, chemotype, endotoxin, germ-free, gnotobiotic, lipopolysaccharide, piglet, toll-like receptor 4, ∆rfa mutant,
• MeSH
• gnotobiologické modely fyziologie   MeSH
• ileum metabolismus   mikrobiologie   MeSH
• kolon metabolismus   mikrobiologie   MeSH
• miniaturní prasata MeSH
• mutace fyziologie   MeSH
• prasata MeSH
• Salmonella typhimurium genetika   izolace a purifikace   MeSH
• salmonelóza genetika   metabolismus   patologie   MeSH
• toll-like receptor 4 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• toll-like receptor 4 MeSH

Salmonella Typhimurium is an enteric pathogen that causes acute and chronic infections in humans and animals. One-week-old germ-free piglets were orally colonized/infected with the Salmonella Typhimurium LT2 strain or its isogenic rough ΔrfaL, ΔrfaG or ΔrfaC mutants with exactly defined lipopolysaccharide (LPS) defects. After 24 h, the piglets were euthanized and the colonization of the small intestine, translocations into the mesenteric lymph nodes, liver, spleen, lungs, and bacteremia, along with changes in the ileum histology, and transcription levels of the tight junction proteins claudin-1, claudin-2, and occludin were all assessed. Additionally, transcription levels of IL-8, TNF-α, and IL-10 in the terminal ileum, and their local and systemic protein levels were evaluated. Wild-type Salmonella Typhimurium showed the highest translocation, histopathological changes, upregulation of claudins and downregulation of occludin, transcription of the cytokines, intestinal IL-8 and TNF-α levels, and systemic TNF-α and IL-10 levels. Depending on the extent of the incompleteness of the LPS, the levels of the respective elements decreased, or no changes were observed at all in the piglets colonized/infected with Δrfa mutants. Intestinal IL-10 and systemic IL-8 levels were not detected in any piglet groups. This study provided foundational data on the gnotobiotic piglet response to colonization/infection with the exactly defined rough Salmonella Typhimurium LT2 isogenic mutants.

• Klíčová slova
• Salmonella Typhimurium, cytokines, germ-free piglet, gnotobiotic, lipopolysaccharide, tight junction proteins, Δrfa mutant,
• MeSH
• cytokiny imunologie   MeSH
• gnotobiologické modely * MeSH
• játra mikrobiologie   MeSH
• lipopolysacharidy toxicita   MeSH
• lymfatické uzliny mikrobiologie   MeSH
• mutace MeSH
• plíce mikrobiologie   MeSH
• prasata MeSH
• Salmonella typhimurium genetika   fyziologie   MeSH
• salmonelóza imunologie   mikrobiologie   patologie   MeSH
• slezina mikrobiologie   MeSH
• tenké střevo imunologie   mikrobiologie   patologie   MeSH
• virulence * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokiny MeSH
• lipopolysacharidy MeSH

Innate immunity is shaped by a complex of redundant and pleiotropic factors that ensure recognition, alert and suppression of pathogens. Innate immune responses in the gut are complicated by the requirement of parallel tolerance to commensal microflora predominating in cell numbers and species. In normal individuals, the intestinal mucosa together with relevant lymph nodes represents a robust barrier against systemic spread of non-typhoid Salmonella. Contemporary insights into these defense mechanisms are reviewed.

• MeSH
• gastrointestinální trakt imunologie   MeSH
• lidé MeSH
• přirozená imunita * MeSH
• Salmonella imunologie   MeSH
• salmonelóza imunologie   MeSH
• slizniční imunita * MeSH
• střevní sliznice imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

In this study we characterized aro mutants of Salmonella enterica serovars Enteritidis and Typhimurium, which are frequently used as live oral vaccines. We found that the aroA, aroD, and aroC mutants were sensitive to blood serum, albumen, EDTA, and ovotransferrin, and this defect could be complemented by an appropriate aro gene cloned in a plasmid. Subsequent microarray analysis of gene expression in the aroD mutant in serovar Typhimurium indicated that the reason for this sensitivity might be the upregulation of murA. To confirm this, we artificially overexpressed murA from a multicopy plasmid, and this overexpression caused sensitivity of the strain to albumen and EDTA but not to serum and ovotransferrin. We concluded that attenuation of aro mutants is caused not only by their inability to synthesize aromatic metabolites but also by their defect in cell wall and outer membrane functions associated with decreased resistance to components of innate immune response.

• MeSH
• albuminy farmakologie   MeSH
• alkyltransferasy a aryltransferasy genetika   MeSH
• aminokyseliny aromatické biosyntéza   genetika   MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální geny * MeSH
• bakteriální léková rezistence genetika   MeSH
• buněčná membrána účinky léků   genetika   MeSH
• buněčná stěna účinky léků   genetika   MeSH
• EDTA farmakologie   MeSH
• fosfoenolpyruvát metabolismus   MeSH
• klonování DNA MeSH
• komplement farmakologie   MeSH
• mutace MeSH
• ovotransferin farmakologie   MeSH
• plazmidy genetika   MeSH
• Salmonella enteritidis účinky léků   enzymologie   genetika   MeSH
• Salmonella typhimurium účinky léků   enzymologie   genetika   MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• sérum MeSH
• testy genetické komplementace MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• albuminy MeSH
• alkyltransferasy a aryltransferasy MeSH
• aminokyseliny aromatické MeSH
• antibakteriální látky MeSH
• EDTA MeSH
• fosfoenolpyruvát MeSH
• komplement MeSH
• ovotransferin MeSH
• UDP-N-acetylglucosamine 1-carboxyvinyltransferase MeSH Prohlížeč