PCR Articolo

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https://hdl.handle.net/11050/33
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Mostra il contenuto di PCR Articolo per Autore "Biosa, Grazia"

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    An Easy and Efficient Method for Native and Immunoreactive Echinococcus granulosus Antigen 5 Enrichment from Hydatid Cyst Fluid
    (Public Library of Science, 2014-08-13) Pagnozzi, Daniela; Biosa, Grazia; Addis, Maria Filippa; Mastrandrea, Scilla; Masala, Giovanna; Uzzau, Sergio
    Background: Currently, the serodiagnosis of cystic echinococcosis relies mostly on crude Echinococcus granulosus hydatid cyst fluid as the antigen. Consequently, available immunodiagnostic tests lack standardization of the target antigen and, in turn, this is reflected on poor sensitivity and specificity of the serological diagnosis. Methodology/Principal Findings: Here, a chromatographic method enabling the generation of highly enriched Antigen 5 (Ag5) is described. The procedure is very easy, efficient and reproducible, since different hydatid cyst fluid (HCF) sources produced very similar chromatograms, notwithstanding the clearly evident and extreme heterogeneity of the starting material. In addition, the performance of the antigen preparation in immunological assays was preliminarily assessed by western immunoblotting and ELISA on a limited panel of cystic echinococcosis patients and healthy controls. Following western immunoblotting and ELISA experiments, a high reactivity of patient sera was seen, with unambiguous and highly specific results. Conclusions/Significance: The methods and results reported open interesting perspectives for the development of sensitive diagnostic tools to enable the timely and unambiguous detection of cystic echinococcosis antibodies in patient sera.
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    Evaluating the Impact of Different Sequence Databases on Metaproteome Analysis: Insights from a Lab-Assembled Microbial Mixture
    (Public Library of Science, 2013-12-09) Tanca, Alessandro; Palomba, Antonio; Deligios, Massimo; Cubeddu, Tiziana; Fraumene, Cristina; Biosa, Grazia; Pagnozzi, Daniela; Addis, Maria Filippa; Uzzau, Sergio
    Metaproteomics enables the investigation of the protein repertoire expressed by complex microbial communities. However, to unleash its full potential, refinements in bioinformatic approaches for data analysis are still needed. In this context, sequence databases selection represents a major challenge. This work assessed the impact of different databases in metaproteomic investigations by using a mock microbial mixture including nine diverse bacterial and eukaryotic species, which was subjected to shotgun metaproteomic analysis. Then, both the microbial mixture and the single microorganisms were subjected to next generation sequencing to obtain experimental metagenomic- and genomic-derived databases, which were used along with public databases (namely, NCBI, UniProtKB/SwissProt and UniProtKB/TrEMBL, parsed at different taxonomic levels) to analyze the metaproteomic dataset. First, a quantitative comparison in terms of number and overlap of peptide identifications was carried out among all databases. As a result, only 35% of peptides were common to all database classes; moreover, genus/species-specific databases provided up to 17% more identifications compared to databases with generic taxonomy, while the metagenomic database enabled a slight increment in respect to public databases. Then, database behavior in terms of false discovery rate and peptide degeneracy was critically evaluated. Public databases with generic taxonomy exhibited a markedly different trend compared to the counterparts. Finally, the reliability of taxonomic attribution according to the lowest common ancestor approach (using MEGAN and Unipept software) was assessed. The level of misassignments varied among the different databases, and specific thresholds based on the number of taxon-specific peptides were established to minimize false positives. This study confirms that database selection has a significant impact in metaproteomics, and provides critical indications for improving depth and reliability of metaproteomic results. Specifically, the use of iterative searches and of suitable filters for taxonomic assignments is proposed with the aim of increasing coverage and trustworthiness of metaproteomic data.
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    Impact of three commercial feed formulations on farmed gilthead sea bream (Sparus aurata, L.) metabolism as inferred from liver and blood serum proteomics
    (BioMed Central, 2014-09-24) Ghisaura, Stefania; Anedda, Roberto; Pagnozzi, Daniela; Biosa, Grazia; Spada, Simona; Bonaglini, Elia; Cappuccinelli, Roberto; Roggio, Tonina; Uzzau, Sergio; Addis, Maria Filippa
    Background: The zootechnical performance of three different commercial feeds and their impact on liver and serum proteins of gilthead sea bream (Sparus aurata, L.) were assessed in a 12 week feeding trial. The three feeds, named A, B, and C, were subjected to lipid and protein characterization by gas chromatography (GC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), respectively. Results: Feed B was higher in fish-derived lipids and proteins, while feeds C and A were higher in vegetable components, although the largest proportion of feed C proteins was represented by pig hemoglobin. According to biometric measurements, the feeds had significantly different impacts on fish growth, producing a higher average weight gain and a lower liver somatic index in feed B over feeds A and C, respectively. 2D DIGE/MS analysis of liver tissue and Ingenuity pathways analysis (IPA) highlighted differential changes in proteins involved in key metabolic pathways of liver, spanning carbohydrate, lipid, protein, and oxidative metabolism. In addition, serum proteomics revealed interesting changes in apolipoproteins, transferrin, warm temperature acclimation-related 65 kDa protein (Wap65), fibrinogen, F-type lectin, and alpha-1-antitrypsin. Conclusions: This study highlights the contribution of proteomics for understanding and improving the metabolic compatibility of feeds for marine aquaculture, and opens new perspectives for its monitoring with serological tests.