Distribution of phenotypic and genotypic antimicrobial resistance and virulence genes in Vibrio parahaemolyticus isolated from cultivated oysters and estuarine water

A total of 594 Vibrio parahaemolyticus isolates from cultivated oysters (n = 361) and estuarine water (n = 233) were examined for antimicrobial resistance (AMR) phenotype and genotype and virulence genes. Four hundred forty isolates (74.1%) exhibited resistance to at least one antimicrobial agent and 13.5% of the isolates were multidrug-resistant strains. Most of the V. parahaemolyticus isolates were resistant to erythromycin (54.2%), followed by sulfamethoxazole (34.7%) and trimethoprim (27.9%). The most common resistance genes were qnr (77.8%), strB (27.4%) and tet(A) (22.1%), whereas bla(TEM) (0.8%) was rarely found. Four isolates (0.7%) from oysters (n = 2) and estuarine water (n = 2) were positive to tdh, whereas no trh-positive isolates were observed. Significantly positive associations among AMR genes were observed. The SXT elements and class 1, 2 and 3 integrons were absent in all isolates. The results indicated that V. parahaemolyticus isolates from oysters and estuarine water were potential reservoirs of resistance determinants in the environment. This increasing threat of resistant bacteria in the environment potentially affects human health. A 'One Health' approach involved in multidisciplinary collaborations must be implemented to effectively manage antimicrobial resistance.