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Published on: July 3, 2014
Early pathogenesis of equine Streptococcus equi infection (strangles)
1Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky 40546-0099, USA.
Equine Veterinary Journal
|January 24, 2009
Summary
Streptococcus equi rapidly enters horse tonsils within hours, reaching lymph nodes quickly. This highlights potential failures in innate immunity and informs intranasal vaccine development.
Area of Science:
- Equine immunology
- Bacterial pathogenesis
- Vaccine development
Background:
- Limited understanding of Streptococcus equi entry and multiplication in horses.
- Need for data to inform intranasal vaccine design and immune response studies.
Purpose of the Study:
- Determine Streptococcus equi entry points after intranasal infection.
- Identify sites of bacterial replication and dispersion.
- Analyze bacterial behavior following commingling exposure.
Main Methods:
- Intranasal inoculation of horses/ponies with S. equi.
- Euthanasia at various time points (1-48h) post-infection.
- Histopathology and fluorescent microscopy of tonsils and lymph nodes.
Main Results:
- Tonsils (oro- and nasopharynx) are primary entry points.
- Rapid carriage to draining lymph nodes within 3 hours.
- Bacterial multiplication observed in tonsillar lymphoid tissue and lymph nodes by 48h.
- Mutant S. equi lacking virulence factors did not reach lymph nodes.
Conclusions:
- S. equi rapidly disseminates to regional lymph nodes.
- Intracellular and extracellular bacterial multiplication indicates immune evasion.
- Suggests potent antiphagocytic activity and innate immune defense failure.
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