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A standardized mouse model of Helicobacter pylori infection: introducing the Sydney strain
A Lee1, J O'Rourke, M C De Ungria
1School of Microbiology and Immunology, The University of New South Wales, Sydney, Australia.
Background & Aims:
Currently available Helicobacter pylori models show variable and, in some instances, poor colonization. There is a need for a strain with high colonizing ability to act as a standard for animal studies.
Methods:
After screening a range of fresh clinical isolates and long-term adaptation in mice, a strain of H. pylon has been isolated with a very good colonizing ability.
Results:
This strain, named the Sydney strain of H. pylori (strain SS1), is cagA and vacA positive. High levels of colonization (10(6)-10(7) colony-forming units/g tissue) were achieved consistently in C57BL/6 mice. Colonization levels varied depending on the mouse strain used with BALB/c, DBA/2, and C3H/He, all being colonized but in lower numbers. In all strains of mice, bacteria were clearly visible at the junctional zone between the antrum and the body. The phenotype was stable with colonizing ability remaining after 20 subcultures in vitro. The bacterium attached firmly to gastric epithelium. During 8 months, a chronic active gastritis slowly developed, progressing to severe atrophy in both C57BL/6 and BALB/c mice.
Conclusions:
The Sydney strain of H. pylori is available to all and will provide a standardized mouse model for vaccine development, compound screening, and studies in pathogenesis.
Insights
A new Sydney strain (SS1) of Helicobacter pylori offers high colonization in mice, establishing a standardized model for research. This cagA and vacA positive strain aids vaccine development and pathogenesis studies.
Area of Science:
- Microbiology
- Immunology
- Gastroenterology
Background:
- Existing Helicobacter pylori models exhibit inconsistent colonization, necessitating a standardized strain for animal research.
- A high-colonizing H. pylori strain is crucial for reliable vaccine development and pathogenesis studies.
Purpose of the Study:
- To isolate and characterize a H. pylori strain with high and stable colonization ability in mice.
- To establish a standardized animal model for H. pylori research.
Main Methods:
- Screening of clinical H. pylori isolates and adaptation in mice.
- Characterization of the isolated strain's colonization ability, stability, and pathological effects in various mouse strains.
Main Results:
- The isolated Sydney strain (SS1) demonstrated high and consistent colonization (10^6-10^7 CFU/g) in C57BL/6 mice.
- SS1 is cagA and vacA positive, attaches firmly to gastric epithelium, and induces chronic active gastritis progressing to severe atrophy.
- Colonization varied across mouse strains (BALB/c, DBA/2, C3H/He), with bacteria localized to the junctional zone.
Conclusions:
- The Sydney strain (SS1) provides a stable and reproducible H. pylori mouse model.
- This standardized model is valuable for vaccine development, compound screening, and pathogenesis research.
- The SS1 strain is readily available for the scientific community.
