To determine the species identity of a rare environmental Pseudomonas isolate recovered from blood culture and to evaluate its antimicrobial resistance profile and pathogenic potential. The isolate PS1 was characterized by MALDI-TOF MS identification, antimicrobial susceptibility testing, and whole-genome sequencing. Species assignment was established using average nucleotide identity (ANI) analysis and core-genome phylogenetic analysis. Virulence- and resistance-associated genes were annotated using multiple databases. Phenotypic validation was performed through biofilm formation, serum killing, chrome azurol S (CAS) iron acquisition assay, and the Galleria mellonella infection model. MALDI-TOF MS misidentified PS1 as Pseudomonas putida, whereas WGS confirmed it as P. soli, showing an ANI value of 99.0536% with P. soli ASM49897v2. PS1 was resistant to some β-lactams and trimethoprim-sulfamethoxazole, but remained generally susceptible to carbapenems, aminoglycosides, and quinolones. Genomic analysis identified virulence-associated modules involved in alginate biosynthesis, iron acquisition, secretion systems, and surface structure remodeling. Phenotypic assays demonstrated that PS1 had strong biofilm-forming ability (OD₅₇₀ = 0.210 ± 0.042) and iron acquisition capacity (CAS halo diameter, 8.63 ± 0.38 mm), showed a certain degree of survival in normal human serum, and exhibited dose-dependent lethality in the Galleria mellonella model. This study reports the first case of bloodstream infection caused by P. soli confirmed by whole-genome sequencing. PS1 harbored multiple virulence‑related genetic modules and exhibited corresponding pathogenic phenotypes. These findings support that P. soli may have opportunistic pathogenic potential.
Chen et al. (Mon,) studied this question.