Customized Bacteria-Induced Models of IBD

Because the microbiome plays an important role in the development and persistence of chronic colitis in the IL-10 KO mouse model, scientists considered injecting fecal suspension or selected bacteria, such as Lactobacillus ssp., Enterobacter aerogenes, Streptococcus viridans, Clostridium ramosum, Bacteroides fragilis, and Bacteroides uniformis into the colon wall of rats to create bacteria-induced models of IBD. All of these infected groups developed chronic colitis and intestinal fibrosis as evidenced by increased collagen content and elevated TGF-β1 levels. Oral administration of Salmonella typhimurium to mice 24 hours after treatment with streptomycin resulted in edema, ulceration, and even full-layer intestinal inflammation. These experiments provide important insights and potential to study the bacterial contribution to inflammatory bowel disease (IBD) in aspects of chronic colitis and fibrosis.

Fig. 1. Schematic diagram of Barley leaf's role in improving Citrobacter rodentium-causing colitis through a preventive approach. Fig. 1. Barley leaf smeliorates Citrobacter rodentium-induced colitis through preventive effects. (Feng et al., 2022)

Our Citrobacter rodentium-Induced Colitis Models

Citrobacter rodentium is a natural mouse Gram-negative pathogenic bacterium with genetic properties and virulence factors that evoke an inflammatory response similar to that induced in humans by enteropathogenic Escherichia coli (EPEC). The team at Ace Therapeutics has extensive experience with preclinical animal models of colitis and provides reliable Citrobacter rodentium-induced colitis models to help clients study the pathogenesis of enteric infection-induced inflammation.

Description	Our infectious colitis models induced with Citrobacter rodentium is a clinically relevant, translational model of intestinal dysbiosis with a range of phenotypic severity based on the host mouse strain.
Modeling Method	We inject of 10⁸-10⁹ Citrobacter rodentium organisms by oral gavage into C57Bl/6 mice to creat a robust model of infectious colitis.
Features	Exhibit colonic hyperplasia or elongation of the crypts, mononuclear immune cell infiltration and goblet cell depletion. Following oral inoculation, Citrobacter rodentium causes a profound gut microbiota dysbiosis that is characterized by an overgrowth of Proteobacteria and a decline in the richness and overall diversity of the resident microbiota. The initial site of colonization is the cecal plaque several hours after attack, which progresses to the distal colon 2 to 3 days after infection. The Citrobacter rodentium burden peaks on day 7 p.i. and remains high up to day 12 p.i., and it is usually cleared by day 21 p.i.
Applications	Examine pathogen-host interactions and immune responses. Study how a bacterial infection can increase the risk of colon cancer. Assess the efficacy of novel therapeutics against EPEC. Characterize the behavior of test compounds in a pathogen-induced, inflammatory setting.

Preclinical Evaluation in Citrobacter rodentium-Induced Colitis Models

As a CRO in the field of IBD, Ace Therapeutics offers a wide range of study endpoints to evaluate models of Citrobacter rodentium-induced colitis models and to develop new preventive and therapeutic approaches.

Percentage change in body weight.
Disease activity index (DAI) score.
Terminal colon weight and length measurements.
Measurement of colonic epithelial barrier permeability in Citrobacter rodentium-infected mice at required time points after infection.
Measurement of bacterial load in tissues and feces of Citrobacter rodentium-infected mice.
Histological assessment and immunofluorescence staining of infected colon tissues.
Cytokine analysis, such as IL-4, IL-1β, TNF-α and IFN-γ.
Immunophenotyping of intestinal cells.
16S rRNA gene sequencing to study changes in microbial communities

Ace Therapeutics' Citrobacter rodentium-induced colitis model is a powerful tool for studying the immune response of the intestinal mucosa. We offer a one-stop service from model construction to novel therapy development. If you are interested in our services, please do not hesitate to contact us.

Reference

Feng, Y., et al. (2022). Barley Leaf Ameliorates Citrobacter rodentium-Induced Colitis through Preventive Effects. Nutrients, 14(18), 3833.

! For research use only, not intended for any clinical use.