Autor(es): Rodrigues, Inês C ; Santos-Ferreira, Nânci ; Silva, Daniela ; da Silva, Carla Chiquelho ; Inácio, Ângela S. ; Nascimento, Maria São José ; da Costa, Paulo Martins
Data: 2023
Identificador Persistente: https://hdl.handle.net/10316/113976
Origem: Estudo Geral - Universidade de Coimbra
Assunto(s): oyster; farming waters; Escherichia coli; salmonella; antimicrobial resistance; norovirus
As filter-feeding animals farmed in water bodies exposed to anthropogenic influences, oysters can be both useful bioremediators and high-risk foodstuffs, considering that they are typically consumed raw. Understanding the dynamic of bacterial and viral load in Pacific oyster (Crassostrea gigas) tissues, hemolymph, outer shell surface biofilm, and farming water is therefore of great importance for microbiological risk assessment. A one-year survey of oysters collected from a class B production area (Canal de Mira, on the Portuguese western coast) revealed that these bivalve mollusks have a good depurating capacity with regard to bacteria, as Salmonella spp. and viable enterococci were not detected in any oyster flesh (edible portion) samples, despite the fact that these bacteria have regularly been found in the farming waters. Furthermore, the level of Escherichia coli contamination was clearly below the legal limit in oysters reared in a class B area (>230-≤4600 MPN E. coli/100 g). On the contrary, norovirus was repeatedly detected in the digestive glands of oysters sampled in autumn, winter, and spring. However, their presence in farming waters was only detected during winter.
This work was supported by the Structured R&D&I Project INNOVMAR–“Innovation and Sustainability in the Management and Exploitation of Marine Resources” (ref. NORTE-01- 0145-FEDER-000035) within the research line “INSEAFOOD-Innovation and valorization of seafood products: meeting local challenges and opportunities”, founded by the Northern Regional Operational Programme (NORTE 2020) through the European Regional Development Fund (ERDF); and funded by the project OCEAN3R (NORTE-01-0145-FEDER-000064), supported by the North Portugal Regional Operational Program (NORTE2020), under the PORTUGAL 2020 Partnership Agreement and through the European Regional Development Fund (ERDF).
