Active Whey Protein Edible Films and Coatings Incorporating Lactobacillus buchneri for Penicillium nordicum Control in Cheese

Fungal contamination of food is responsible for health issues and food waste. In this work, the incorporation of a lactic acid bacteria (LAB) with antifungal properties (Lactobacillus buchneri UTAD104) into whey protein-based films and coatings was tested for the control of an ochratoxigenic fungi (Penicillium nordicum) in a cheese matrix. The incorporation of L. buchneri cells resulted in thicker films with less luminosity than control films and colour alteration. Nevertheless, cells inclusion did not alter moisture content, water vapour permeability, mechanical properties, hydrophobicity and chemical structure of the films. Whey protein films were able to maintain the viability of L. buchneri UTAD104 cells in 105 CFU/mL after 30 days of storage at 25 \textdegreeC. When applied in cheese, films and coatings containing L. buchneri cells prevented fungal contamination for at least 30 days, while control cheeses with films and coatings either without LAB or with Lactobacillus casei UM3 (a strain without antifungal ability) showed fungal contamination during that period. Ochratoxin A was not found in cheeses treated with films and coatings containing L. buchneri UTAD104. Results showed that the inclusion of a LAB with antifungal properties in edible films and coatings can help to reduce or eliminate P. nordicum contamination in cheeses.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Guimarães received support through grant SFRH/BD/103245/2014 from the Portuguese FCT.info:eu-repo/semantics/publishedVersio

T-2 toxin inhibits the differentiation of human monocytes into dendritic cells and macrophages

International audienc

Effect of PR toxin on THP1 and Caco-2 cells: an in vitro study

International audiencePenicillium roqueforti produces mycotoxins including PR toxin, which is a food and feed contaminant. In this study, PR toxin was purified from culture material of the Penicillium roqueforti F43-1 strain. Toxic effects were evaluated in undifferentiated human Caco-2 intestinal epithelial cells and THP-1 monocytic immune cells. To understand the mechanisms involved in PR-toxin toxicity, cell death and pro-inflammatory gene expression were studied. In addition, PR toxin degradation was assessed. Cytotoxicity studies showed a dose-dependent effect of PR toxin and the calculated mean cytotoxic concentration (IC50) concentrations were for Caco-2 and THP-1 cells >12.5 and 0.83 mu M, respectively. Gene expression studies showed that tumour necrosis factor-a expression was significantly increased after 24 h exposure to 312 mu M PR toxin. PR toxin induced necrosis on THP-1 cells after 3 h exposure. In the cell culture system, the PR toxin showed a 10-fold reduction in PR toxin concentration within 48 h, indicating that PR toxin was degraded by THP-1. To conclude, PR toxin appears to be one of the most cytotoxic P. roqueforti mycotoxins on Caco-2 and/or THP-1 cells and induces in THP-1 cells both necrosis and an inflammatory response

Evaluation de la cytotoxicité de la roquefortine C et de l’acide mycophénolique, et quantification de ces mycotoxines dans des fromages à pâte persillée par LC-MS/MS

Evaluation de la cytotoxicit\ue9 de la roquefortine C et de l\u2019acide mycoph\ue9nolique, et quantification de ces mycotoxines dans des fromages \ue0 p\ue2te persill\ue9e par LCMS/MS Fontaine K\ue9vin1, Hymery Nolwenn1, Mounier J\ue9r\uf4me1, Passero Elena2, Vallone Lisa2, Barbier Georges1, Coton Emmanuel1 La fabrication des fromages \ue0 p\ue2te persill\ue9e (bleus, gorgonzola, stilton\u2026) implique l\u2019utilisation de souches s\ue9lectionn\ue9es de P. roqueforti qui jouent un r\uf4le pr\ue9pond\ue9rant dans les qualit\ue9s organoleptiques de ces produits. En outre, P. roqueforti poss\ue8de un potentiel de production de m\ue9tabolites secondaires tels que la roquefortine C (ROQ C), les isofumigaclavines A et B, la toxine PR et l\u2019acide mycoph\ue9nolique (AM). A l\u2019heure actuelle, il existe des donn\ue9es parcellaires concernant leur cytotoxicit\ue9 et leur pr\ue9sence dans les fromages. L\u2019objectif de ce travail a \ue9t\ue9 une analyse quantitative de la ROQ C et de l\u2019AM effectu\ue9e dans 76 fromages \ue0 p\ue2te persill\ue9e issus d\u2019une quinzaine de pays diff\ue9rents, par chromatographie liquid coupl\ue9e \ue0 la spectrom\ue9trie de masse en tandem (LC-MS/MS)

Occurrence of roquefortine C, mycophenolic acid and aflatoxin M1 mycotoxins in blue-venied cheeses

Penicillium roqueforti, a food and feed contaminant, is known for its potential to produce roquefortine C (ROQC) and mycophenolic acid (MPA) amongst other mycotoxins. In blue-veined cheeses, selected P.roqueforti ripening cultures are used for organoleptic development but little is known about mycotoxin occurrence in these products. In this study, aflatoxin M1 (AFM1), ROQC and MPA levels were determined in 86 blue-veined cheeses collected worldwide using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). AFM1 was absent in all samples while 97.7% and 37.2% of cheeses contained quantifiable ROQC and MPA levels, respectively. Overall, the analyzed cheeses contained a large range of mycotoxin concentrations with ROQC and MPA mean levels at 848\ub11670\u3bcg/kg and 841\ub11271\u3bcg/kg, respectively. Noteworthy, 75% of cheese samples contained less than 792\u3bcg/kg ROQC and 705\u3bcg/kg MPA

Lactobacilli intra-tracheal administration protects from Pseudomonas aeruginosa pulmonary infection in mice - a proof of concept

WOS:000501544400007International audienceThe spreading of antibiotic resistance is a major public health issue, which requires alternative treatments to antibiotics. Lactobacilli have shown abilities to prevent pneumonia in clinical studies when given by oral route, certainly through the gut-lung axis involvement. Rationally, respiratory administration of lactobacilli has been developed and studied in murine model, to prevent from respiratory pathogens. It allows a direct effect of probiotics into the respiratory system. To our knowledge, no study has ever focused on the effect of probiotic intra-respiratory administration to prevent from Pseudomonas aeruginosa (PA) pneumonia, a major respiratory pathogen associated with high morbidity rates. In this study, we evaluated the beneficial activity of three Lactobacillus strains (Lactobacillus fermentum K.C6.3.1E, Lactobacillus zeae Od.76, Lactobacillus paracasei ES.D.88) previously screened by ourselves and known to be particularly efficient in vitro in inhibiting PAO1 virulence factors. Cytotoxic assays in alveolar epithelial cell line A549 were performed, followed by the comparison of two lactobacilli prophylactic protocols (one or two administrations) by intra-tracheal administration in a C57BL/6 murine model of PA pneumonia. A549 cells viability was improved from 23 to 75% when lactobacilli were administered before PAO1 incubation, demonstrating a protective effect (P\textless0.001). A significant decrease of 2 log of PAO1 was observed 4 h after PAO1 instillation (3x 10(6) cfu/mouse) in both groups receiving lactobacilli (9x 10(6) cfu/mouse) compared to PAO1 group (P\textless0.05). One single prophylactic administration of lactobacilli significantly decreased the secretion by 50% in bronchoalveolar lavages of interleukin (IL)-6 and tumour necrosis factor-a compared to PAO1. No difference of secretion was observed for the IL-10 secretion, whatever the prophylactic study design. This is the first study highlighting that direct lung administration of Lactobacillus strains protect against PA pneumonia. Next step will be to decipher the mechanisms involved before developing this novel approach for human applications