Objective To characterize the differences in antibiotic susceptibility and genetic polymorphism between Vibrio parahaemolyticus strains isolated from shrimps from breeding farms or markets and from foodborne disease cases.

Methods The analysis on V. parahaemolyticus isolates from shrimp breeding farming or markets and foodborne disease cases was conducted through serum typing, virulence gene detection, antibiotic susceptibility testing, and whole-genome sequencing.

Results A total of 52 strains of V. parahaemolyticus were isolated from shrimps from breeding farms and markets, they belonged to 12 serotypes and virulence genotype tdh⁻/trh⁻. The antibiotic susceptibility test indicated that 43 strains (82.69%) were resistant to cefazolin, 17 strains (32.69%) were resistant to streptomycin, and 8 strains (15.38%) were resistant to ampicillin. MLST revealed ST2366 as the predominant sequence type (12 strains, 23.08%). In contrast, 25 strains V. parahaemolyticus from foodborne disease cases belonged to 4 serotypes and genotype tdh⁺/trh⁻. The antibiotic susceptibility test indicated that 20 strains (80.00%) were resistant to cefazolin, 3 strains (12.00%) were resistant to polymyxin E, and 2 strains (8.00%) were to gentamicin, with ST3 being the predominant sequence type (23 strains, 92.00%).

Conclusion The V. parahaemolyticus strains isolated from shrimp breeding farms and markets showed greater genetic diversity in terms of serotype and sequence type. The study results provided evidence for the early warning and targeted prevention of foodborne disease caused by V. parahaemolyticus, and indicated the necessity to strengthen the surveillance for the virulence characteristics and antibiotic resistance of V. parahaemolyticus in seafoods in local area.