Vibrio parahaemolyticus, a significant foodborne pathogen, is widespread in marine, estuarine and coastal environments. Consumption of raw or undercooked aquatic products contaminated with V. parahaemolyticus can lead to acute gastroenteritis (Ghenem et al., 2017; Hiyoshi et al., 2010; Raszl et al., 2016; Zhang and Orth, 2013). This pathogen is responsible for an estimated 35,000 foodborne illnesses annually in the United States (Scallan et al., 2011) and has becoming the leading cause of bacterial gastroenteritis in southern coastal region of China (Li et al., 2014), highlighting a major global public health concern.

Antibiotics like tetracycline and ciprofloxacin are commonly used to treat V. parahaemolyticus infections (Centers for Disease Control and Prevention CDC, 2013; Park et al., 2018). However, the overuse and misuse of these antibiotics have led to the rise of resistant V. parahaemolyticus strains in the aquatic environment, posing alarming threats to public health (Elmahdi et al., 2016; Lee and Raghunath, 2018; Obaidat et al., 2017). V. parahaemolyticus has increasingly become resistant to various antibiotics, including tetracycline, penicillin, ampicillin, and ceftazidime (Elmahdi et al., 2016; Vu et al., 2022). Studies from Korea, India, Malaysia, Saudi Arabia, and Vietnam have reported that V. parahaemolyticus isolates showed resistance to multiple antibiotics such as ampicillin, penicillin, ceftazidime, cefotaxime, and cefpodoxime (Elhadi et al., 2022; Jo et al., 2020; Narayanan et al., 2020; Parthasarathy et al., 2021; Tan et al., 2020). Fang et al. (2023) reported a significant increase in the quantity of antibiotic resistance genes (ARGs) and multi-drug resistance (MDR) phenotypes in V. parahaemolyticus from 1951 to 2021. The elevating prevalence of MDR V. parahaemolyticus represents a critical threat to public health. Consequently, monitoring the antibiotic resistance of V. parahaemolyticus is of immediate necessity.

Thermostable direct hemolysin (TDH), TDH-related hemolysin (TRH) respectively encoded by tdh and trh genes， are considered to be the main pathogenic factors of V. parahaemolyticus (Li et al., 2019). A study reported that the harboring rate of tdh, trh or both genes, were up to 9.90 %, 19.80 % or 3.96 % among the foodborne V. parahaemolyticus isolated from China (Li et al., 2020). However, the prevalence of MDR, the distribution of antibiotic resistance genes, and their co-existence with virulence genes in V. parahaemolyticus from Chinese aquatic foods were yet to be further elucidated. Therefore, this study focused on the antimicrobial susceptibility and genomic characterization of 163 V. parahaemolyticus isolated from various seafood, freshwater fish, and other food sources across 15 provinces in China.