Citrobacter ⇒ Citrobacter rodentium {10000222}

Shared Reference Notes

• [1.1] 
  - Switching mice from a standard grain-based rodent chow to a high-fat, low-fiber #Western-style diet resulted in a rapid reduction in the number of gut bacteria. - Mice fed the #Western-style diet were frequently unable to clear the pathogen Citrobacter rodentium from the colon. They were also prone to developing chronic infection when re-challenged by this pathogen.
• [1.2] [#Pectin] 
  - Pectins > anti-inflammatory properties on intestinal immunity > direct interactions on Toll-like receptors (TLRs) in the small intestine or via stimulating microbiota-dependent effects in the large intestine. - Pectins> prevent C. rodentium induced colonic inflammation > lowering the C. rodentium load in the caecum independently of the DB.
• [1.3] [#Vitamin A] 
  - Commensal segmented filamentous bacteria protect against C. rodentium infection - Commensal bacteria express enzymes that generate #Retinoic acid in the intestine - Commensal bacterial-derived #Retinoic acid promotes epithelial defense in the host
• [1.4] 
  - C. rodentium was able to catabolize #Sialic acid, a monosaccharide derived from mucins, and utilize it as its sole carbon source for growth. - C. rodentium also sensed and displayed chemotactic activity toward #Sialic acid. These activities were abolished when the nanT gene, encoding a #Sialic acid transporter, was deleted (ΔnanT). - the ΔnanT C. rodentium strain was significantly impaired in its ability to colonize the murine intestine. Intriguingly, #Sialic acid was also found to induce the secretion of two autotransporter proteins, Pic and EspC, which possess mucinolytic and host-adherent properties. - #Sialic acid enhanced the ability of C. rodentium to degrade intestinal mucus (through Pic), as well as to adhere to intestinal epithelial cells (through EspC).
• [1.5] [#Roseomonas mucosa] 
  - The #Segmented filamentous bacteria (SFB) can improve the immune response of mucosal tissues. - SFB are bacteria that can not be cultured present at weaning in the ileum of mice. - This bacterial species induces the immune response of the gut mucosa after birth. - In the absence of SFB, mice were found to possess reduced IgA titers and decreased numbers of helper T-cells (especially Th17 cells). - they had a weak response to intestinal pathogenic bacteria such as #Salmonella and Citrobacter rodentium
• [1.6] 
  - #Indole and its derivatives seem to increase the integrity of the epithelial barrier and function of tight junctions > reduce #Colitis related to Citrobacter rodentium and #Candida albicans infection
• [1.7] 
  - during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes greater epithelial access and lethal #Colitis by the mucosal pathogen, Citrobacter rodentium.

References Notes