Table 1_Genomic and phenotypic characterization of a multidrug-resistant Pseudomonas putida strain associated with skin ulceration disease in farmed sea cucumbers (Apostichopus japonicus).xlsx

Furthermore, whole-genome sequencing was used to elucidate the mechanistic basis of pathogenicity and identify a suite of virulence-associated genes mainly involved in motility (flagella and type IV pili), immune evasion (LPS, LOS, and alginate), and iron acquisition (pyoverdine), providing a genetic framework for understanding SUD pathogenesis. Antibiotic susceptibility testing showed multidrug resistance to 19 antibiotics and susceptibility to cefotaxime, ceftriaxone, imipenem, and aztreonam; the resistance phenotype was supported by a corresponding resistome, including mexw, mexb, mexf, baca, and adeF.

The observed optimal growth at 30.22 °C and low salinity (10.78‰) raises the testable hypothesis that outbreak risk may be elevated when environmental conditions favor bacterial proliferation. For therapeutic management, we propose a framework incorporating environmental monitoring (temperature, salinity, pH), targeted antibiotic selection (prioritizing cephalosporins), and long-term alternatives such as phage therapy.

To our knowledge, this study provides the first complete whole-genome and genetic blueprint of P. putida associated with SUD in sea cucumbers, providing actionable insights for SUD control.</p>