Clinical emergence of a novel sequence type (ST3672) NDM-1-producing Vibrio parahaemolyticus in foodborne disease

Background: ) strain (VP1434), isolated directly from a patient involved in a food poisoning outbreak, highlighting its rare multidrug resistance (MDR) phenotype. The objectives were to investigate its resistance mechanisms, elucidate its evolutionary relationships, and assess its pathogenicity. Methods: The VP1434 isolate was analyzed as follows: (1) Antimicrobial susceptibility was tested against 29 antibiotics, and plasmid conjugation experiments verified drug resistance in recipient strains post-transfer. (2) Whole-genome sequencing was used to characterize its genomic features, including plasmid sequences and inter-plasmid relationships. (3) Evolutionary tracing of VP1434 and the plasmid pVP1434-NDM was performed by constructing phylogenetic trees. (4) Virulence factors (VFs) were identified via the Virulence Factor Database, and pathogenicity was assessed through mouse infection. Results: ), suggesting TRH plays a significant role in pathogenicity even in the absence of TDH. Conclusion: reveals plasmid-mediated MDR emergence in human infections. Its unexpected virulence without classical toxins indicates evolutionary adaptation, necessitating diagnostic updates and strengthened surveillance.