Molecular epidemiology and antimicrobial resistance of Vibrio parahaemolyticus isolates from aquatic products in the Southern Fujian coast, China.

Vibrio parahaemolyticus, a globally distributed bacterium in estuarine and coastal waters, poses a significant threat to seafood safety. The spread of antimicrobial resistance (AMR) in V. parahaemolyticus transcends phylogenetic, geographic, and ecological boundaries, raising concerns about its impact on marine ecosystems. This study investigated the prevalence and AMR profiles of V. parahaemolyticus in seafood in retail markets in Zhangzhou City, China. A total of 288 aquatic samples were collected aseptically from July 2023 to June 2024. Sixty-one V. parahaemolyticus isolates were identified using standard methods (cultural, biochemical, PCR) and characterized for virulence genes, AMR genes, antibiotic susceptibility, and molecular type. Multi-drug resistance (MDR) was then analyzed. The overall isolation rate of V. parahaemolyticus was 21% (61/288). A significant proportion of isolates exhibited high resistance to minocycline (97%), penicillin (93%), and cefazolin (90%). Lower resistance rates were observed for piperacillin (3%), ceftriaxone (5%), ceftazidime (7%), and cefoperazone (7%). Multi-antimicrobial resistance (MAR) indices revealed that 54% of isolates were resistant to more than ten antimicrobials. ERIC-PCR and RAPD typing grouped the isolates into four clusters each, with the majority (86.89% and 88.13%, respectively) belonging to Group I, indicating a high degree of genetic similarity among many isolates. The high prevalence of MDR V. parahaemolyticus in retail seafood suggests excessive antimicrobial use in aquaculture practices within this region. Effective antimicrobial stewardship programs, coupled with comprehensive surveillance, are urgently needed to mitigate the development and spread of AMR in V. parahaemolyticus and safeguard both human health and the health of marine ecosystems from pollution linked to aquaculture practices.