Scientists unlock mechanism behind food poisoning from bivalves
risk from mussels, oysters and clams to the consumer.
Bivalves, important vehicles for the transmission of enteric diseases when eaten raw of undercooked, have food safety implications.
Vibrio species, including human pathogens, are particularly abundant in bivalve tissues, where they can persist even after cleaning.
Researchers at the Universities of Genova and Urbino in Italy conclude that different vibrio species and strains seem to adopt a common strategy used by pathogenic bacteria in mammalian cells.
"They undermine host cell functions through disregulation of its signalling pathways," says Laura Canesi, from the University of Urbino.
Although different environmental factors are well known to affect the persistence of vibrios in these organisms, the researchers highlighted their latest finding as the key behind interactions between vibrios and the immune system of bivalves.
Carla Pruzzo, from the University of Genova explains: "In bivalves, immunity is carried out by circulating haemocytes and soluble haemolymph factors that act in a co-ordinated way to kill microorganisms.
Our research examines available data on vibrio interactions with both cellular and soluble components of the bivalve immune system in the light of the capacity of bacteria to evade the hemolymph bactericidal activity and to develop pathogenic effects in the bivalve host."
Using data collected with an in vitro model of Vibrio cholerae attacking the immune system of the Mediterranean seafood Mytilus galloprovincialis, the scientists identified a range of factors that are important in determining the fate of vibrios within the bivalve host.
These are bacterial surface ligands, soluble hemolymph components and the ability of bacteria to influence distinct signalling pathways responsible for the haemocyte immune response.
Food safety is a driving issue for industry and governments (that foot the healthcare costs) in the increasingly industrialised, and complex, society.
According to the UN-backed World Health Organisation, in industrialised countries, the percentage of people suffering from foodborne diseases each year has been reported to be up to 30 per cent.
In the US, for example, around 76 million cases of foodborne diseases, resulting in 325,000 hospitalisations and 5,000 deaths, are estimated to occur each year.
Full findings are published in the June 2005 issue (6) of Environmental Microbiology.
Food safety is a driving issue for industry and governments in the increasingly industrialised society.
According to the UN-backed World Health Organisation, in industrialised countries, the percentage of people suffering from foodborne diseases each year has been reported to be up to 30 per cent.
In the US, for example, around 76 million cases of foodborne diseases, resulting in 325,000 hospitalisations and 5,000 deaths, are estimated to occur each year.
