Genomic characterization of the Taylorella genus.
Authors: Hébert Laurent, Moumen Bouziane, Pons Nicolas, Duquesne Fabien, Breuil Marie-France, Goux Didier, Batto Jean-Michel, Laugier Claire, Renault Pierre, Petry Sandrine
Journal: PloS one
Summary
# Editorial Summary: Genomic characterization of the Taylorella genus Taylorella equigenitalis causes contagious equine metritis (CEM), a notifiable reproductive disease of significant economic and welfare concern, whilst its close relative Taylorella asinigenitalis predominantly affects donkeys; this 2012 study provided the first comprehensive genomic comparison between these two understudied pathogens. Using whole-genome sequencing, Hébert Laurent and colleagues sequenced T. asinigenitalis (1.64 million base pairs, 1,534 genes) and compared it systematically with the previously sequenced T. equigenitalis genome, identifying both shared and unique genetic features. Whilst the two species shared 1,322 genes, T. equigenitalis possessed 234 additional genes absent in T. asinigenitalis, including multiple virulence factors such as haemagglutin-related proteins, type IV secretion systems, and iron-acquisition receptors—features likely explaining its greater pathogenic potential and capacity for causing acute reproductive disease. Both organisms appear to utilise malate, glutamate and alpha-ketoglutarate as primary energy sources, and both carry multiple secretion systems and host-colonisation proteins, yet T. equigenitalis's enhanced genetic toolkit for immune evasion and tissue invasion correlates with its more severe clinical presentation. For equine practitioners, these findings underpin the biological basis for CEM's epidemiological behaviour and host specificity, offering molecular markers for future diagnostic development and suggesting targets for understanding treatment resistance and vaccination strategies.
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Practical Takeaways
- •Understanding the genomic basis of T. equigenitalis virulence may lead to improved diagnostic tools and treatment strategies for contagious equine metritis
- •The identification of specific pathogenic mechanisms provides targets for vaccine development and antimicrobial interventions
- •The genetic differences between T. equigenitalis and T. asinigenitalis explain why contagious equine metritis is a significant equine problem while donkey disease is less severe
Key Findings
- •T. asinigenitalis genome is 1,638,559 bp with 1,534 coding sequences, sharing 1,322 orthologs with T. equigenitalis
- •T. equigenitalis possesses significantly more virulence factors than T. asinigenitalis including type IV secretion systems and lactoferrin/transferrin receptors
- •Both species likely utilize malate, glutamate, and alpha-ketoglutarate as primary carbon and energy sources
- •Four different secretion systems and host-binding proteins were identified in both species, indicating strong host-pathogen interaction potential