Chlamydia muridarum Infection Impacts Murine Models of Intestinal Inflammation and Cancer

Area of Science:

• Microbiology
• Immunology
• Gastroenterology

Background:

• Chlamydia muridarum is a prevalent pathogen in mouse colonies.
• Its impact on gastrointestinal disease models is not well understood.

Purpose of the Study:

• To evaluate the effect of C. muridarum on mouse models of intestinal inflammation and tumorigenesis.

Main Methods:

• Mice (C57BL/6J, Il10-/-, ApcMin/+) were infected with C. muridarum via cohousing.
• Subsequent infection or treatment models included Citrobacter rodentium, Trichuris muris, Helicobacter hepaticus, and dextran sodium sulfate (DSS).
• Lesion severity and tumorigenesis were assessed.

Main Results:

• C. muridarum attenuated C. rodentium-induced colitis.
• It had no effect on T. muris-associated pathology.
• It worsened colitis in Il10-/- mice without H. hepaticus.
• It reduced DSS-induced colonic tumorigenesis in ApcMin/+ mice.

Conclusions:

• C. muridarum colonization differentially affects intestinal inflammation and tumorigenesis models.
• The presence of C. muridarum should be considered a variable in mouse experimental studies.