Thesis Helsens Nicolas

Helsens Nicolas

Characterization of the bacterial communities and antimicrobial resistance profiles in the rainbow trout fillet

Abstract :

Food of animal origin could play a role in the spreading of antimicrobial resistance. The consumption of fresh farmed fish fillets is increasing, and they can be contaminated by the farming and processing environments, which can modify their antimicrobial resistance profiles. This study is a first characterization of the antimicrobial resistance profiles of the rainbow trout fillet bacterial microbiota. Various situations were considered to study the evolution of the fillets exposure. The bacterial microbiota and antimicrobial resistance profile of 56 farm-collected samples were described after a calibration of recovery and analyses methods adapted to this complex matrix with low contamination levels. The bacterial microbiota is similar between samples but the processing step seems to be a diversity factor for the bacterial communities. A low number of antimicrobial resistance genes have been detected with a prevalence of 20% or more in the fish raceway population. They seem to be influenced by the previous antibiotic treatments whose residues were detected. Pseudomonas strains also have been isolated and some harboured multidrug resistance. Spoilage of the fillets increases the amount of detected antimicrobial resistance genes and the abundance of Pseudomonas. This may present a risk as some genes were present but undetected in fresh fillets, which can transfer such genes to other environments such as the consumers’ intestinal microbiota.

Key words :

Antimicrobial resistance, bacterial communities, antibiotic residues, fish fillet, resistance profiles

Modification date : 11 September 2023 | Publication date : 07 February 2022 | Redactor : ML