Genomic characterization of Staphylococcus epidermidis Se252 isolated from the rhizosphere of a Brazilian endemic plant

Staphylococcus epidermidis (Se) is commonly regarded as a commensal organism; however, under specific conditions, it may act as an opportunistic pathogen. Here, we report the whole-genome sequencing and comparative genomic analysis of Se strain 252 (Se252), isolated from the rhizosphere of an endemic Brazilian plant. Se252 exhibits a unique repertoire of genes associated with environmental adaptation and virulence. These include two putative Type VII secretion system (T7SS) effectors and thirteen proteins involved in adhesion, toxin production, and immune evasion—among them, IsaB, which has not been previously reported in Se. Gene family expansions were observed in loci related to phenol-soluble modulins (PSMs), TLpps, LPXTG-motif proteins, nonribosomal peptide synthetases (NRPS), and siderophore biosynthesis (staphylopine, staphyloferrin), as well as quorum-sensing autoinducing peptides. In contrast, Se252 harbors relatively few antibiotic resistance genes. The genomic profile of Se252 reflects adaptations to a plant-associated environment, yet harbors multiple features potentially enhancing human pathogenicity. These findings highlight the relevance of environmental Se lineages as possible reservoirs of virulence traits with implications for public health.