Streptococcusdysgalactiae subsp. equisimilis from Diseased Pigs Are Genetically Distinct from Human Strains and Associated with Multidrug Resistance.

ABSTRACT: Streptococcus dysgalactiae subsp. equisimilis (SDSE) has historically been recognized as a human pathogen, yet β-hemolytic streptococci consistent with SDSE have been documented in pigs for nearly a century. To investigate the population structure of porcine SDSE and the phylogenetic relationships between swine and human strains, we characterized 41 isolates recovered from diseased pigs in Quebec, Canada (2019-2022). Infected animals spanned all major production stages and frequently presented with invasive disease, including arthritis, endocarditis, and sudden death. Core-genome phylogenetics resolved two heterogeneous porcine clades separated by long internal branches and clearly distinct from dominant human SDSE lineages. Most porcine isolates were emm-negative or c

SUBMITTER: Hsu F 

PROVIDER: S-EPMC12843900 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature