Purpose: The purpose of this study was to: 1) determine presence of β-hemolytic Aeromonas spp. and Vibrio spp. as indicators of microbial contamination in seafood; 2) identify isolates using biphasic method, and 3) determine potential virulent strains of Aeromonas spp. by presence of the hlyA gene.
Methods: Isolation was performed with protocol of the National Institute of Health in Colombia. Strains were identified by 9 biochemical tests, CrystalTM kit, and analysis of 16S rDNA gene. Vibrio spp. recovery was validated with standardized dilution plate, and a multiplex-PCR the dnaJ gene was standardized. To assess the virulence of Aeromonas spp., primers were designed and standardized PCR to hylA. Vibrio spp. recovery was validated using Thiosulfate Citrate Bile Sucrose (TCBS) agar.
Results: No sample was positive for Vibrio spp. Seventy percent of the strains of Aeromonas spp. phenotypically identified were confirmed by CrystalTM and 63% with sequencing 16S, with no significant differences between the methods. One hundred percent of Aeromonas spp. were β-hemolytic and 70% were confirmed by amplified and sequencing of hlyA.
Significance: β-hemolytic Aeromonas spp. isolated in seafood represents a potential risk to consumers. No sample was positive for Vibrio spp., but the selectivity of the medium was a point of interest. Adequate refrigeration promotes seafood safety. Although pathogens can grow in refrigerated products, satisfactory phenotypic and molecular characterization helps strengthen the quality and safety of fishery products.