Bacterial community in sardines condemned for histamine contamination: a case study in the canned fish industry

Abstract

Abstract In some fish species, such as tuna, mackerel, and sardines, improper handling after fishing promotes the growth of histamine-forming bacteria. If consumed, histamine-contaminated fish can cause various symptoms, including vomiting, diarrhea, erythema, urticaria, and even anaphylaxis in severe cases. Understanding the main bacteria responsible for histamine production is crucial for public health. This study utilized next-generation sequencing to analyze the bacterial community in histamine-contaminated sardines. For this study, 1000 g of muscle samples were collected from 40–45 sardines per batch, all obtained from the same supplier, fishing area, and time period, for histamine analysis. Samples from five different batches with ≥ 200 ppm of histamine (contaminated) and five with < 1 ppm (non-contaminated) underwent microbial analysis. Histamine-contaminated sardines exhibited lower microbial diversity and a higher abundance of the genera Photobacteria and Shewanellae. These bacteria thrive under mild temperatures and indicate fish spoilage and the production of biogenic amines. In contrast, Psychobacter and Pseudoalteromonas, known to withstand harsh conditions, including low temperatures, were more prevalent in non-contaminated sardines. Our findings suggest that contaminated sardines experienced inadequate refrigeration during transportation and processing, indicating the potential use of Psychobacter and Pseudoalteromonas as quality indicators for fish.