Molecular Insights and Virulence Genes Profiling of Some Vibrio Species Isolated from Commonly Consumed Seafood and Their Implications on Seafood Quality

Seafood is a known reservoir for Vibrio species, some of which carry virulence factors and can be acquired via handling and cross-contamination in the retail markets, which may pose public health risks. This study investigated the prevalence, virulence-associated genes, and spoilage effects of Vibrio spp. isolated from 400 samples from eight seafood species collected in Egypt. Microbiological and molecular identification were conducted using conventional methods and confirmatory PCR assays targeting species-specific and virulence-associated genes. Vibrio spp. were detected in 51.75% of the samples, from which 66.6% were identified as virulent species: V. parahaemolyticus (33.3%), V. cholerae (22.2%), and V. vulnificus (11.1%). Gene screening revealed the presence of toxR and vvh in all V. parahaemolyticus and V. vulnificus isolates, while ctx and hylA were found in 60% and 10% of V. cholerae isolates, respectively. Quality assessments of contaminated seafood showed elevated levels of total volatile base nitrogen (TVB-N) and moderate changes in pH, indicating spoilage. Thiobarbituric acid reactive substances (TBA-RS) values remained within acceptable limits, suggesting limited lipid oxidation. These findings bring to light the public health and quality concerns associated with Vibrio-contaminated seafood and emphasize the need for routine monitoring and comprehensive risk assessments.