1. Disinfection in a salmon processing plant: Impact on bacterial communities and efficacy towards foodborne bacteria and biofilms.
- Author
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Reiche T, Hageskal G, Hoel S, Tøndervik A, Nærdal GK, Heggeset TMB, Haugen T, Trøen HH, and Jakobsen AN
- Subjects
- Animals, Seafood microbiology, Food Handling methods, Aquaculture, Microbial Sensitivity Tests, Microbiota, Food-Processing Industry, Food Contamination prevention & control, Food Contamination analysis, Food Safety, Salmon microbiology, Biofilms growth & development, Biofilms drug effects, Disinfection methods, Bacteria drug effects, Bacteria growth & development, Bacteria classification, Bacteria isolation & purification, Disinfectants pharmacology, Food Microbiology
- Abstract
Salmon aquaculture is the fastest growing food production system in the world. Deficiencies in the quality or safety of salmon can have global repercussions. Controlling food safety aspects during production is therefore essential. Here, we investigate the state of hygiene in a salmon processing plant using next generation sequencing and classical culture-dependent methods to characterize the surface microbiota before and after cleaning and disinfection (C&D) at ten surface sampling points. Total aerobic counts revealed an average reduction in the bacterial loads of 1.1 log CFU/cm
2 by C&D. The highest relative abundance in the core microbiota before C&D was assigned to Acinetobacter, Mycoplasmataceae, Pseudomonas and Enterobacteriaceae in descending order. After C&D, we observed a significant increase in the relative abundance of Pseudomonas (p < 0.05). However, variations were found between conveyors, processing machines and drains. To assess the efficacy of commercial disinfectants, we performed susceptibility assays using advanced robotic high-throughput technologies and included foodborne bacteria which may affect food safety and spoilage. These included 128 Pseudomonas isolates, 46 Aeromonas isolates and 59 Enterobacterales isolates sampled from the salmon processing plant. Generally, minimum inhibitory concentrations (MICs) of the disinfectants were below the user concentration recommended by the producer for most isolates. BacTiter-Glo biofilm assays revealed that 30 min exposure to six out of eight commercial disinfectants resulted in an average reduction of relative luminescence >95 % in 59 single-species biofilms selected for screening. However, disinfection alone may not always be sufficient to eradicate biofilms completely. C&D routines must therefore be continuously assessed to maintain food safety and quality. The results from this study can contribute to understand and improve the state of hygiene in salmon processing environments., Competing Interests: Declaration of competing interest None to declare., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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