References of "Daube, Georges"
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See detailComparative Genomic Analysis Reveals Ecological Differentiation in the Genus Carnobacterium.
Iskandar, Christelle F.; Borges, Frederic; Taminiau, Bernard ULiege et al

in Frontiers in Microbiology (2017), 8

Lactic acid bacteria (LAB) differ in their ability to colonize food and animal-associated habitats: while some species are specialized and colonize a limited number of habitats, other are generalist and ... [more ▼]

Lactic acid bacteria (LAB) differ in their ability to colonize food and animal-associated habitats: while some species are specialized and colonize a limited number of habitats, other are generalist and are able to colonize multiple animal-linked habitats. In the current study, Carnobacterium was used as a model genus to elucidate the genetic basis of these colonization differences. Analyses of 16S rRNA gene meta-barcoding data showed that C. maltaromaticum followed by C. divergens are the most prevalent species in foods derived from animals (meat, fish, dairy products), and in the gut. According to phylogenetic analyses, these two animal-adapted species belong to one of two deeply branched lineages. The second lineage contains species isolated from habitats where contact with animal is rare. Genome analyses revealed that members of the animal-adapted lineage harbor a larger secretome than members of the other lineage. The predicted cell-surface proteome is highly diversified in C. maltaromaticum and C. divergens with genes involved in adaptation to the animal milieu such as those encoding biopolymer hydrolytic enzymes, a heme uptake system, and biopolymer-binding adhesins. These species also exhibit genes for gut adaptation and respiration. In contrast, Carnobacterium species belonging to the second lineage encode a poorly diversified cell-surface proteome, lack genes for gut adaptation and are unable to respire. These results shed light on the important genomics traits required for adaptation to animal-linked habitats in generalist Carnobacterium. [less ▲]

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See detailUnraveling microbial ecology of industrial-scale Kombucha fermentations by metabarcoding and culture-based methods.
Coton, Monika; Pawtowski, Audrey; Taminiau, Bernard ULiege et al

in FEMS Microbiology Ecology (2017), 93(5),

Kombucha, historically an Asian tea-based fermented drink, has recently become trendy in Western countries. Producers claim it bears health-enhancing properties that may come from the tea or metabolites ... [more ▼]

Kombucha, historically an Asian tea-based fermented drink, has recently become trendy in Western countries. Producers claim it bears health-enhancing properties that may come from the tea or metabolites produced by its microbiome. Despite its long history of production, microbial richness and dynamics have not been fully unraveled, especially at an industrial scale. Moreover, the impact of tea type (green or black) on microbial ecology was not studied. Here, we compared microbial communities from industrial-scale black and green tea fermentations, still traditionally carried out by a microbial biofilm, using culture-dependent and metabarcoding approaches. Dominant bacterial species belonged to Acetobacteraceae and to a lesser extent Lactobacteriaceae, while the main identified yeasts corresponded to Dekkera, Hanseniaspora and Zygosaccharomyces during all fermentations. Species richness decreased over the 8-day fermentation. Among acetic acid bacteria, Gluconacetobacter europaeus, Gluconobacter oxydans, G. saccharivorans and Acetobacter peroxydans emerged as dominant species. The main lactic acid bacteria, Oenococcus oeni, was strongly associated with green tea fermentations. Tea type did not influence yeast community, with Dekkera bruxellensis, D. anomala, Zygosaccharomyces bailii and Hanseniaspora valbyensis as most dominant. This study unraveled a distinctive core microbial community which is essential for fermentation control and could lead to Kombucha quality standardization. [less ▲]

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See detailHigh-throughput sequencing analysis reveals the genetic diversity of different regions of the murine norovirus genome during in vitro replication
Mauroy, Axel ULiege; Taminiau, Bernard ULiege; Nezer, Carine et al

in Archives of Virology (2017), 16(4), 1019-1023

In this study, we report the genetic diversity and nucleotide mutation rates of five representative regions of the murine norovirus genome during in vitro passages. The mutation rates were similar in ... [more ▼]

In this study, we report the genetic diversity and nucleotide mutation rates of five representative regions of the murine norovirus genome during in vitro passages. The mutation rates were similar in genomic regions encompassing partial coding sequences for non-structural (NS) 1-2, NS5, NS6, NS7 proteins within open reading frame (ORF) 1. In a region encoding a portion of the major capsid protein (VP1) within ORF2 (also including the ORF4 region) and a portion of the minor structural protein (VP2), the mutation rates were estimated to be at least one order of magnitude higher. The VP2 coding region was found to have the highest mutation rate. [less ▲]

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See detailUse of the potential probiotic strain Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers.
Saint-Cyr, Manuel Jimmy; Haddad, Nabila; Taminiau, Bernard ULiege et al

in International Journal of Food Microbiology (2017)

Campylobacteriosis is the most frequently reported zoonotic disease in humans in the EU since 2005. As chicken meat is the main source of contamination, reducing the level of Campylobacter in broiler ... [more ▼]

Campylobacteriosis is the most frequently reported zoonotic disease in humans in the EU since 2005. As chicken meat is the main source of contamination, reducing the level of Campylobacter in broiler chicken will lower the risk to consumers. The aim of this project was to evaluate the ability of Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers and to investigate the mechanisms that could be involved. Thirty broilers artificially contaminated with C. jejuni were treated by oral gavage with MRS broth or a bacterial suspension (107CFU) of Lb. salivarius SMXD51 (SMXD51) in MRS broth. At 14 and 35days of age, Campylobacter and Lb. salivarius loads were assessed in cecal contents. The impact of the treatment on the avian gut microbiota at day 35 was also evaluated. At day 14, the comparison between the control and treated groups showed a significant reduction (P<0.05) of 0.82 log. After 35days, a significant reduction (P<0.001) of 2.81 log in Campylobacter loads was observed and 73% of chickens treated with the culture exhibited Campylobacter loads below 7log10CFU/g. Taxonomic analysis revealed that SMXD51 treatment induced significant changes (P<0.05) in a limited number of bacterial genera of the avian gut microbiota and partially limited the impact of Campylobacter on Anaerotruncus sp. decrease and Subdoligranulum sp. increase. Thus, SMXD51 exhibits an anti-Campylobacter activity in vivo and can partially prevent the impact of Campylobacter on the avian gut microbiota. [less ▲]

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See detailChemical composition and antimicrobial activity of essential oils of Ocimum basilicum, Ocimum canum and Ocimum gratissimum in function of harvesting time
Mith, Hasika; Yayi-Ladékan, Eléonore; Dosso Sika Kpoviessi, Salomé et al

in Journal of Essential Oil-Bearing Plants [=JEOBP] (2016), 19(6), 1413-1425

The chemical composition of essential oils obtained by hydrodistillation from aerial parts of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as affected by harvesting time, were analyzed ... [more ▼]

The chemical composition of essential oils obtained by hydrodistillation from aerial parts of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as affected by harvesting time, were analyzed by GC-FID (Gas chromatography-Flame ionization detector) and GC-MS (Gas chromatography-Mass spectrometry). Based on the composition analysis, major components were as follows: estragol (43.0-44.7%) and linalool (24.6 29.8%) in O. basilicum oils; carvacrol (12.0-30.8%) and p-cymene (19.5-26.2%) in O. canum oils; thymol (28.3-37.7%) and γ-terpinene (12.5-19.3 %) in O. gratissimum oils. Disc diffusion and broth microdilution assays were used to evaluate the antibacterial activity of essential oils and their main components against two foodborne bacteria, Listeria monocytogenes and Salmonella enterica serotype Typhimurium. The tested oils and their components exhibited notable antimicrobial activities against L. monocytogenes and S. Typhimurium. The O. canum and O. gratissimum oils collected at 7h and 19h showed significant higher activities against L. monocytogenes and S. Typhimurium (MICs and MBCs 0.34 - 2.5 μL/mL) (p < 0.05), whereas O. basilicum showed lower activity (MICs and MBCs 2.0 - 8.0 μL/mL) at any daytime of harvest, the weakest being at 19h (MIC and MBC 12.0 - 32.0 μL/mL). The daytime of harvest can influence the composition of oils and their activities on bacteria. [less ▲]

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See detailDevelopment of an analytical method for the simultaneous measurement of 10 biogenic amines in food
Douny, Caroline ULiege; Benmedjadi, Soumaya; Blaszczyk, Marie et al

Poster (2016, October 21)

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See detailMetabolites from media supplemented with 3’-sialyllactose and fermented by bifidobacteria have an antivirulent effect against intestinal pathogens
Bondue, Pauline ULiege; Daube, Georges ULiege; Delcenserie, Véronique ULiege

Poster (2016, October 21)

Complex oligosaccharides from human milk (HMO) promote growth of Bifidobacterium bifidum. Oligosaccharides from cow milk (BMO), similar to HMO, are mainly represented in colostrum by 3’-sialyllactose ... [more ▼]

Complex oligosaccharides from human milk (HMO) promote growth of Bifidobacterium bifidum. Oligosaccharides from cow milk (BMO), similar to HMO, are mainly represented in colostrum by 3’-sialyllactose (3’SL). Bifidobacterium crudilactis, a species from bovine origin and encoding for β galactosidases and α-glucosidases, could be able to metabolise them. Also, fermentation products could have antivirulent activity against intestinal pathogens. This study focused on capacity of bifidobacteria to metabolise 3’SL and on potential antivirulent effect of cell-free spent media (CFSM) against pathogenic bacteria. B. bifidum BBA1 and B. crudilactis FR/62/B/3 isolated respectively from breastfed children feces and cow raw milk cheese were grown on media supplemented with 3’SL as sole source of carbon. Next, CFSM effects were tested against virulence gene expression using ler and hilA promoter activity of luminescent constructs of Escherichia coli 0157:H7 ATCC 43888 and Salmonella Typhimurium SA 941256, respectively. The effect was confirmed on wild type strains of E. coli O157:H7 ATCC 43890 and S. Typhimurium ATCC 14028 using RT-qPCR. Both strains were able to grow in presence of 3’SL. CFSM resulted in under-expression of hilA and ler genes for the luminescent constructs and in under-expression of ler (ratios of -15.4 and -8.1) and qseA (ratios of -2.1 and -3.1) genes for the wild type strain of E. coli O157:H7. No effect was observed with S. Typhimurium. Little is known about CFSM metabolites and they have to be isolated and identified. The potential synbiotic effect between 3’SL and bifidobacteria will be tested using the Shime®, a human gastrointestinal model. [less ▲]

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See detailConsumption patterns, bacteriological quality and risk factors for Salmonella contamination in meat-based meals consumed outside the home in Kigali, Rwanda
Niyonzima, Eugène; Ongol, Martin Patrick; Brostaux, Yves ULiege et al

in Food Control (2016)

Meat-based meals are consumed as a source of animal proteins and constitute one of the leading vehicles for food borne infections in humans. The main objective of this study was to determine the ... [more ▼]

Meat-based meals are consumed as a source of animal proteins and constitute one of the leading vehicles for food borne infections in humans. The main objective of this study was to determine the consumption pattern and the bacteriological quality of meat-based meals consumed outside households in Kigali. A survey on meat consumption patterns was carried out in 400 households by using a questionnaire, whereas different meat-based meals were sampled from 150 snack bars and restaurants. Enumeration of hygiene indicator bacteria (total mesophilic bacteria and Escherichia coli) and the qualitative detection of Salmonella were carried out by using conventional culture methods. The results indicated that goat was the type of meat that was consumed the most outside the home in Kigali and the meat intake varied significantly (p ≤0.05) with the social category of the household. The average levels of total aerobic bacteria and E. coli in meat-based meals were found to be 4.7 and 1.4 log cfu/g, respectively, whereas Salmonella was detected in 11.7% of all meat-based meals. Eight factors mostly linked to the cooking treatments and hygienic handling practices for cooked meals were found to be significantly (p ≤ 0.05) associated with the risk of Salmonella occurrence in meat-based meals consumed outside the home in Kigali. The findings from this study strongly suggest the need for proper cooking and/or improvements in hygiene in the establishments selling ready-to-eat meat-based meals in Kigali, particularly those located in rural localities. [less ▲]

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See detailComparative analysis of the respiratory microbiota of healthy dogs and dogs with canine idiopathic pulmonary fibrosis
Roels, Elodie ULiege; Taminiau, Bernard ULiege; Darnis, Elodie ULiege et al

in Journal of Veterinary Internal Medicine (2016, September)

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See detailStudy of the microbial diversity of microbial ring trials by metagenomic analysis : Quantification of alive bacteria by exclusion of dead bacteria
Fall, P.A.; Burteau, S.; Detry, E. et al

Poster (2016, July 19)

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See detailMetagenetics and predictive microbiology: a new tool to understand the kinetics of microbial subpopulations in Belgian white pudding
Cauchie, Emilie ULiege; Gand, Mathieu; Kergourlay, Gilles et al

Poster (2016, July 18)

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See detailChallenge testing with Brochothrix thermosphacta on minced pork meat shows interest to couple metagenetics to metabolomics to study food spoilage
Baré, Ghislain ULiege; Cauchie, Emilie ULiege; Leenders, Justine ULiege et al

Poster (2016, July)

The spoilage of perishable foods is mainly caused by bacterial activity. The risk of unwanted bacterial growth is particularly high in the minced pork meat. In this work, the natural microbial ... [more ▼]

The spoilage of perishable foods is mainly caused by bacterial activity. The risk of unwanted bacterial growth is particularly high in the minced pork meat. In this work, the natural microbial contaminants of the minced pork meat were followed by 16S ribosomal DNA deep sequencing (metagenetics) during aging tests at different temperatures. Brochothrix thermosphacta MM008 strain was selected as one of the main contaminants responsible for the spoilage of the meat. Minced pork meat previously sterilized by gamma irradiation was inoculated with B. thermosphacta MM008 for challenge tests measuring growth and then incubated at different temperatures. Minced meat samples were taken and analyzed by H-NMR 1D at time 0 and at final time (from 14 to 19 days, depending on the incubation temperature). Orthogonal partial least square discriminant analysis (OPLS-DA) showed that samples, regardless of the incubation temperature, could be splitted into 3 groups according to their spectral profile: 1) samples taken at time 0, 2) samples inoculated with B. thermosphacta and taken at final time, 3) samples uninoculated, taken at final time. From the analysis of the metabolomics data, higher concentrations of glycerol, glucose, taurine, lactate, carnitine, betaine and glycine were identified in the samples of uninoculated minced pork meat and an increased production of creatine, acetate and acetone was found in the samples of minced pork meat inoculated with B. thermosphacta MM008. These observations showed that -omics technologies (metagenetics and metabolomics) could be used conclusively to study microbial spoilage of minced pork meat. [less ▲]

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See detailEffects of protein source and cooking procedure on intestinal microbiota and on fermentation end-products in rats
POELAERT, Christine ULiege; Despret, Xavier; Portetelle, Daniel ULiege et al

Poster (2016, June)

Animal and plant proteins are major proteins sources in the human diet. After their enzymatic degradation in the upper gastro-intestinal tract, the undigested fraction of these proteins is available for ... [more ▼]

Animal and plant proteins are major proteins sources in the human diet. After their enzymatic degradation in the upper gastro-intestinal tract, the undigested fraction of these proteins is available for fermentation by the microbiota of the large intestine leading to the production of short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), ammonia, biogenic amines, sulphur metabolites, phenols and indoles. As some of these compounds have genotoxic and cytotoxic effects, protein fermentation is considered as detrimental to the host’s epithelial health. BCFA are usually used as a marker of intestinal protein fermentation. We studied in vivo the impact of proteins from animal and plant origin, raw or after a cooking procedure, on the composition of gut microbiota and on fermentation end-products. Weanling rats were used as models of the human gut microbiota. Eight experimental diets were formulated with beef meat (Longissimus dorsi), chicken meat (Pectoralis major), white pea beans (Phaseolus vulgaris), soybeans (Glycine max), used raw and cooked, as sole source of protein in the diet. One casein diet was used as control. All diets, formulated to contain 15% of raw protein, were given to seven rats for four weeks. After euthanasia, caecal contents were collected. Pyrosequencing analyses (Roche 454 GS Junior Genome Sequencer) were performed to study the microbial composition. SCFA and BCFA were measured using HPLC (Waters 2690). Microbial composition in the caecum is associated to the type of dietary protein and to the cooking procedure applied. The proportion of BCFA in the caecal content is mainly affected by the type of protein. So BCFA represent respectively 04-06% and 35-44% of total SCFA with diets based on plant and on animal proteins. In conclusion, both the type of protein and the cooking procedure could impact the gut microbiota in terms of composition and of fermentative capacity. [less ▲]

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