Importance of Steroid Catabolism in Rhodococcus equi Pathogenicity and Vaccine Development
Author Information
Author(s): van der Geize R., Grommen A. W. F., Hessels G. I., Jacobs A. A. C., Dijkhuizen L.
Primary Institution: University of Groningen, Groningen, The Netherlands
Hypothesis
The orthologous genes in the cholesterol catabolic gene cluster of Rhodococcus equi are essential for its virulence mechanism.
Conclusion
Genes involved in steroid catabolism are promising targets for the development of a live-attenuated vaccine against Rhodococcus equi infections.
Supporting Evidence
- Mutant strains RE1ΔipdAB and RE1ΔfadE30 were impaired in growth on steroid catabolic pathway intermediates.
- RE1ΔipdAB could be safely administered intratracheally to foals and elicited protective immunity.
- Challenge experiments showed that foals vaccinated with RE1ΔipdAB had lower clinical signs of disease compared to controls.
Takeaway
Rhodococcus equi can make foals very sick, but scientists found that certain genes help it grow and could be used to create a safe vaccine.
Methodology
The study involved gene deletion mutants of R. equi and assessed their growth on steroid substrates and their pathogenicity in macrophage infection assays and foal challenge experiments.
Limitations
The study did not fully establish the mechanisms by which steroid catabolism affects pathogenicity.
Participant Demographics
Young foals aged 2 to 5 weeks were used in the challenge experiments.
Statistical Information
P-Value
p<0.02
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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