Population Structure, Novel Sequence Types, and Antimicrobial Resistance in Vibrio parahaemolyticus and Vibrio vulnificus: A Whole Genome Sequencing Study of Clinical and Seafood Isolates in New Jersey

Vibrio parahaemolyticus and Vibrio vulnificus are significant foodborne pathogens linked to seafood consumption and environmental exposure. Whole genome sequencing (WGS) was performed on Vibrio isolates collected from clinical cases and seafood sources throughout the state of New Jersey to elucidate genomic diversity, antimicrobial resistance (AMR) profiles. Sequences were included from isolates collected over eight years, from June 2016 to November 2024. This study identified 465 Vibrio sequences, 406 sequences from seafood sources and 59 sequences from clinical cases. Species-level taxonomic identification via Kraken2 classified 300 isolates as Vibrio parahaemolyticus and 165 as Vibrio vulnificus from whole genome assemblies. Multi-locus sequence typing (MLST) indicated a diverse population of isolates, with 169 known Vibrio sequence types (STs) identified. An additional 168 potential novel allelic profiles were identified, comprising 19.3% of V. parahaemolyticus sequences and 90.9% of V. vulnificus sequences. Novel sequence types were submitted to pubMLST for classification, resulting in the identification of 49 novel V. parahaemolyticus STs and 113 novel V. vulnificus STs. Three V. parahaemolyticus sequence types were identified in both clinical and environmental sequences. A single novel sequence type was identified in both clinical and environmental sequences of V. vulnificus. Analysis of antimicrobial resistance genes revealed the presence of the tetracycline resistance gene tet(34) in nearly all isolates. Beta-lactamase genes were detected in nearly all V. parahaemolyticus sequences but were absent from V. vulnificus, with gene profiles varying by sequence type. To the best of our knowledge, this study provides the first comprehensive WGS-based analysis of the genomic diversity and antimicrobial resistance profiles of Vibrio parahaemolyticus and Vibrio vulnificus isolates from clinical and seafood sources in New Jersey over an eight-year period, to support public health surveillance of these foodborne pathogens.