Related Experiment Video
Updated: Feb 18, 2026
Models of Murine Vaginal Colonization by Anaerobically Grown Bacteria
Published on: May 25, 2022
Infant Rabbit Colonization Competition Assays
1Department of Microbiology and Immunobiology, Harvard Medical School, Boston, USA.
Insights
A new infant rabbit model accurately mimics human cholera, aiding the study of enteric pathogens like Vibrio cholerae. This assay is crucial for developing new vaccines and therapeutics against bacterial intestinal colonization.
Area of Science:
- Microbiology
- Infectious Diseases
- Pathogenesis Research
Background:
- Enteric pathogens, including Vibrio cholerae and enteropathogenic Escherichia coli, cause severe diarrheal diseases.
- Understanding bacterial intestinal colonization mechanisms is vital for developing effective treatments and vaccines.
- Existing models do not fully replicate human disease symptoms or facilitate high-throughput screening.
Purpose of the Study:
- To introduce a modified Infant Rabbit Colonization Competition Assay for studying enteric bacterial pathogenesis.
- To provide a more clinically relevant animal model for Vibrio cholerae infections compared to traditional models.
- To enable high-throughput screening for bacterial colonization factors.
Main Methods:
- A modified nonsurgical animal model using a competition assay in 2-day-old New Zealand white rabbits.
- Inoculation of mixed wild-type and mutant bacterial strains to measure competitive index.
- Assessment of colonization capacity relative to wild-type strains in the gastrointestinal tract.
Main Results:
- The infant rabbit model exhibits clinical and histologic signs closely resembling human cholera.
- The assay allows for the measurement of bacterial colonization capacity through competitive indices.
- The model's capacity for larger bacterial inputs supports high-throughput screening methods like Tn-Seq.
Conclusions:
- The Infant Rabbit Colonization Competition Assay is a valuable tool for studying enteric bacterial pathogenesis.
- This model offers improved clinical relevance for Vibrio cholerae research.
- The assay facilitates the discovery of bacterial colonization factors and aids in therapeutic and vaccine development.
Abstract:
Enteric pathogenic bacteria such as Vibrio cholerae and enteropathogenic Escherichia coli (E. coli) cause life-threatening diarrheal diseases that have afflicted humans for centuries. Understanding the effectors required for intestinal colonization is very important to research on bacteria pathogenesis, and is also important to testing new therapeutics and development of the novel vaccines. Here, we describe the Infant Rabbit Colonization Competition Assay, a variant method of the powerful, nonsurgical animal model reported by Ritchie et al. (2010). In our modified assay, wild type and mutant strains are mixed together and inoculated into 2-day-old New Zealand white rabbits. The competitive index for each mutant measures the colonization capacity of the mutant relative to its wild type parental strain in the gastrointestinal tract. Compared to the traditional Sucking Mice model, the clinical and histologic signs of Vibrio cholerae (V. cholera)-induced disease of infant rabbits more closely resemble human cholera. The larger input bacteria amount of this model also facilitates high-throughput screens, such as Tn-Seq technology (Fu et al., 2013).
