Genotypic diversity of Salmonella ser. Abortusequi isolates from Argentina.
Authors: Bustos C P, Moroni M, Caffer M I, Ivanissevich A, Herrera M, Moreira A R, Guida N, Chacana P
Journal: Equine veterinary journal
Summary
# Salmonella Abortusequi: Understanding Genotypic Variation in Equine Abortion Cases *Salmonella enterica* subsp. *enterica* serovar Abortusequi is an equine-restricted pathogen responsible for abortion outbreaks with significant economic consequences; its emergence in Argentina prompted investigation into the genetic diversity of circulating strains. Researchers analysed 95 kb virulence plasmids and the *spvC* gene across multiple isolates, building on previous molecular characterisation work that had established these genetic elements as critical virulence determinants. Whilst earlier studies from Japan, Mongolia and Croatia had revealed remarkably high clonality in *S. Abortusequi* populations, the Argentine isolates demonstrated considerably greater genotypic diversity, suggesting distinct evolutionary pathways or epidemiological origins for South American strains. This variation has practical implications for diagnostic protocols and vaccine development strategies, as the genetic heterogeneity observed may influence strain-specific virulence and immune response, necessitating region-specific approaches to outbreak management and prevention rather than relying on assumptions of monomorphic pathogenicity across geographical regions.
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Practical Takeaways
- •S. Abortusequi should be considered in equine abortion outbreaks, particularly given its emerging presence in Argentina and other regions
- •Molecular characterization of virulence factors (95 kb plasmid and spvC gene) can aid in diagnosis and understanding disease pathogenesis
- •The high clonality observed suggests that once identified in a region, control measures may be more straightforward due to limited genetic variation
Key Findings
- •S. Abortusequi is a serotype restricted to equines that produces abortion outbreaks and is being reported in multiple countries including Argentina
- •The 95 kb virulence plasmid and spvC gene are important molecular markers for S. Abortusequi pathogenicity
- •High clonality of S. Abortusequi has been identified in Japan, Mongolia, and Croatia, suggesting limited genetic diversity