No abstract

The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres seems to be formed nearly totally by the 222Q variant provides evidence that the 222K PrP variant confers resistance to conversion to PrPres formation and reinforces the view that this mutation has a protective role against classical scrapie in goats.

As the world wild fish stocks are limited and the market demand increases, fish farming has become an alternative food source and a way to reduce costs for consumers. The sale of farmed as wild fish is a fraudulent practice, it is therefore important to work to provide new and alternative tools that can help in the fight against fraud in order to protect consumers and to ensure food traceability. The proteomic profile of farmed and wild fish differs from one another. With this study we wanted to identify liver protein markers via two-dimensional electrophoresis (2DE) that would allow us to distinguish wild from farmed gilthead seabream.The liver samples from 32 gilthead seabream, wild and farmed, were stored at -80 °C before protein extraction. The samples were subjected to 2DE to detect qualitative and quantitative differences. Proteomic analysis showed a protein spot (molecular weight of ~34 kDa and isoelectric point of ~6.9) only in the samples from the wild gilthead seabream; liquid chromatography tandem mass spectrometry identified the spot as ubiquitin. Ubiquitin could be a valid marker to differentiate wild from farmed gilthead seabream, thus ensuring continuous monitoring throughout the entire commercial chain and fight commercial fraud.

No abstract

Background: Fiore Sardo PDO is one of the oldest Mediterranean hard cheeses, exclusively produced in Sardinia (Italy) from raw whole ewe's milk. Some manufacturers, improperly, submit raw milk to heat-treatment. Aim of this study was to evaluate the proteomic profile of Fiore Sardo PDO and to investigate possible differences between cheese made from raw milk and from heat-treated milk. Materials and methods: Starting from the same ovine bulk milk, eight cheese wheels of Fiore Sardo PDO were produced, four from raw milk and four from heat-treated milk. The subsequent production steps were the same for both types of cheese as was sampling at different ripening times. Samples were analyzed by Urea-PAGE electrophoresis. Afterwards, blind analysis of 32 cheese samples, produced by 17 different cheesemakers was performed to evaluate the method's analytical performance. Results: Urea-PAGE analysis showed the presence of a protein band only in cheese made from raw milk, regardless of cheese ripening time. Protein identification analysis by liquid chromatography mass spectrometry identified two different proteins in the band, alpha-S1 and alpha-S2 casein. Blind analyses conducted to verify the analytical performance of the method showed that it could be a useful tool for the protection of this typical agri-food product. Conclusion: We developed a simple, robust, and economic method for discriminating between Fiore Sardo PDO cheese made from raw milk with up to 24 months of maturation and Sardinian sheep milk cheese made from heattreated milk.