Next Generation Sequencing (NGS) for the Determination of Fish Flesh Microbiota

The objective of the study is the assessment of the microbial ecology and safety of fish in Greece using next-generation sequencing (NGS) and the correlation of the species of microbial flora with the production of histamine. Fourteen different fish species were obtained from local fish stores (Greece) within 1 day from capture. The initial microbiota in fish flesh was determined using NGS. The main pathogenic bacterial species identified in the tested fish samples included Vibrio spp., Clostridium spp., Staphylococcus, Flavobacterium and Janthinobacterium representing both native freshwater habitats and contaminants arising from different sources, including sewage and direct contamination by wild animals, livestock, and feed. The initial spoilage microbiota of fish consisted of several psychrotrophic Gram-negative bacteria, such as Pseudomonas, Acinetobacter, Moraxella, Shewanella, Psychrobacter, Lactobacillus, Brochothrix and Photobacterium. The results of the study show the potential of the application and the usefulness of NGS for the determination of microbial flora associated with food-borne diseases and spoilage in fish products. Histamine formation correlated with the valid reads (concentration and number of bacteria) and slightly with the genus of the identified microorganisms.