In-depth characterization of virulence traits, pathogenicity, antibiogram, and antibiotic resistance genes of MDR Vibrio parahaemolyticus retrieved from shrimp.

V. parahaemolyticus poses a remarkable public health threat, accounting for approximately 25% of global seafood-related infections in human consumers and resulting in severe infections and substantial economic losses in the aquaculture. To explore the prevalence, antibiogram, virulence and resistance genes, the multidrug resistance profiles, and the pathogenicity of V. parahaemolyticus recovered from shrimp, 200 Litopenaeus vannamei (clinically healthy: n = 100 and diseased: n = 100) were gathered from commercial shrimp farms in Ismailia, Egypt. Accordingly, clinical and postmortem findings and bacteriological examinations were performed. All the recovered isolates were positive for the groEL and Ap3 genes, indicating that all the retrieved isolates were AHPND-causing strains. The prevalence of V. parahaemolyticus in the examined shrimp was 11% (22/200), where the hepatopancreas was the prominent infected organ. Using PCR, the prevalence of the toxR, tlh, tdh, and trh virulence genes was 100%, 98%, 80%, and 28%, respectively. Moreover, 42% of the obtained V. parahaemolyticus strains were MDR to seven antimicrobial classes and had the blaTEM, tetA, blaOXA, sul1, aadA, and ermB genes. In addition, 16% of the isolated strains were MDR to six classes and had the blaTEM, tetA, blaOXA, aadA, and ermB genes. The pathogenicity trial emphasized the positive correlation between the inherited virulence genes of the tested strains and the recorded mortalities. In brief, this investigation highlighted the development of MDR V. parahaemolyticus in shrimp, affirming a public health threat. The evolving MDR V. parahaemolyticus strains usually carry the Ap3, toxR, tlh, and tdh virulence genes, and the ermB, blaTEM, aadA, blaOXA, sul1, tetA, and/or tetB antibiotic resistance genes.