Abstract:Objective Different enrichment approaches were employed to isolate Vibrio parahaemolyticus (VP) from environmental samples, aiding in the traceability analysis of an outbreak. Methods Collected the epidemiological data and clinical information, and real time PCR and bacterial culture were performed in the samples. Whole genome sequencing and bioinformatics analysis were performed on the isolates in this outbreak. Results Seven strains of tdh+VP with O10:K4 serotype isolated from 4 patients and 3 environmental smear samples. The SNPs among the 7 strains ranged from 0 to 5 based on the analysis of single nucleotide polymorphisms in the core genome. All environmental smear samples were negative for VP by real time PCR and culture method based on 3%NaCl Alkaline Peptone Water (APW) enhancement. By brain heart infusion broth(BHI) enhancement, the real time PCR results showed that E1, E2 and E6 were toxR+/tdh+, and the Ct values of E1 and E2 were > 30 in all testd targets. The E1 and E2 samples cultured by BHI were re-cultured with 3%NaCl APW, and Ct values of E1 and E2 target genes were < 30, and VP culture was positive. Conclusion In this study, the isolation of VP in environmental samples was supported by different bacterial growth schemes to investigate and trace the source of an outbreak caused. The effective bacterial growth methods of VP in environmental smear samples need to be further studied.