References of "Daube, Georges"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailEffects of protein source and cooking procedure on intestinal microbiota and on fermentation end-products in rats
POELAERT, Christine ULg; Despret, Xavier; Portetelle, Daniel ULg 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 ▲]

Detailed reference viewed: 20 (5 ULg)
Full Text
Peer Reviewed
See detailLaboratory identification of anaerobic bacteria isolated on Clostridium difficile selective medium
Rodriguez Diaz, Cristina ULg; Warszawski, Nathalie; Korsak Koulagenko, Nicolas ULg et al

in Acta Microbiologica et Immunologica Hungarica (2016)

Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardised. Cycloserine cefoxitin fructose taurocholate (CCFT) has historically been the ... [more ▼]

Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardised. Cycloserine cefoxitin fructose taurocholate (CCFT) has historically been the most used medium for C. difficile isolation from human, animal, environmental and food samples, and presumptive identification is usually based on colony morphologies. However, CCFT is not totally selective. This study describes the recovery of 24 bacteria species belonging to 10 different genera other than C. difficile, present in the environment and foods of a retirement establishment that were not inhibited in the C. difficile selective medium. These findings provide insight for further environmental and food studies as well as for isolation of C. difficile on supplemented CCFT. [less ▲]

Detailed reference viewed: 83 (16 ULg)
Full Text
See detailAssociation of Targeted metagenomic analysis and classical microbiology for Clostridium difficile detection and microbial ecosystem mapping of surfaces hands and foodstuffs in a meat processing plant
Rodriguez Diaz, Cristina ULg; Oukbir, Meriem; Taminiau, Bernard ULg et al

Poster (2016, May 11)

INTRODUCTION Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test positive ... [more ▼]

INTRODUCTION Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test positive for the bacterium, it seems plausible that C. difficile could be zoonotic. PURPOSE This study aimed to determine the prevalence and the epidemiology of C. difficile in cattle farms and the possible spread of the bacterium among animals and farmers. METHODS A total of 176 faecal samples of cattle were collected from 5 different Belgian farms. A stool sample of each farmer was also requested. Detection of C. difficile was performed by classical culture on C. difficile selective medium (cycloserine cefoxitin fructose cholate). Isolates were characterised by PCR-ribotyping and Genotype Cdiff test (Hain Lifescience), which allows the detection of all toxin genes, mutations in gyrA gene and the deletion in the regulator gene tcdC. RESULTS C. difficile was detected in 14/178 (7.9%) animal samples. Isolates were grouped into five different types, including PCR-ribotype 015. All of them were identified as toxigenic. In contrast, none of the 5 farmers studied were positive for the bacterium. SIGNIFICANCE Results obtained indicate that PCR-ribotypes commonly isolated from hospitalised patients are also present in cattle, indicating an animal reservoir. However, a zoonotic transmission could be not demonstrated in the farms studied. [less ▲]

Detailed reference viewed: 30 (5 ULg)
Full Text
Peer Reviewed
See detailDaily intake and bacteriological quality of meat consumed in the households of Kigali, Rwanda
Niyonzima, Eugene ULg; Ongol, Martin Patrick; Brostaux, Yves ULg et al

in Food Control (2016), 69

Meat is consumed worldwide as a source of animal proteins, but it is recognized as one of the most important vehicles for food borne infections in humans. This study was conducted to determine the daily ... [more ▼]

Meat is consumed worldwide as a source of animal proteins, but it is recognized as one of the most important vehicles for food borne infections in humans. This study was conducted to determine the daily intake; the levels of hygiene indicator bacteria, namely the total mesophilic bacteria (TMC) and Escherichia coli counts (ECC); and the prevalence of Salmonella in meat consumed within the households of Kigali (Rwanda). The survey on meat consumption was carried out in 400 households by using a questionnaire, whereas the bacteriological analyses of meat samples were performed by using conventional culture methods. The results from the survey indicated that beef was the type of meat mostly consumed in Kigali city households, and the daily meat intake significantly varied with the social category of the household. No significant difference was observed between daily meat intakes in different age classes of household members. In the samples where microorganisms were detected, the average levels of TMCs and ECCs in raw meat were found to be 5.4 and 1.6 log cfu/g, respectively, whereas in cooked meat they were significantly reduced to 3.1 and 1.1 log cfu/g, respectively. The prevalence of Salmonella was reduced from 21.4% in raw meat to 3.4% in ready-to-eat cooked meat. Salmonella was not detected in cooked meat consumed in high-income households. The results from this study highlight the need for hygiene improvements in meat shops as well as in the households of Kigali, particularly those with low and medium incomes. [less ▲]

Detailed reference viewed: 34 (16 ULg)
Full Text
Peer Reviewed
See detailIdentification of Shiga toxin-producing (STEC) and enteropathogenic (EPEC) Escherichia coli in diarrhoeic calves and comparative genomics of O5 bovine and human STEC
Fakih, Ibrahim; Thiry, Damien ULg; Duprez, Jean-Noël ULg et al

in Veterinary Microbiology (2016)

Escherichia coli producing Shiga toxins (Stx) and the attaching-effacing (AE) lesion (AE-STEC) are responsible for (bloody) diarrhoea in humans and calves while the enteropathogenic E. coli (EPEC ... [more ▼]

Escherichia coli producing Shiga toxins (Stx) and the attaching-effacing (AE) lesion (AE-STEC) are responsible for (bloody) diarrhoea in humans and calves while the enteropathogenic E. coli (EPEC) producing the AE lesion only cause non-bloody diarrhoea in all mammals. The purpose of this study was (i) to identify the pathotypes of enterohaemolysin-producing E. coli isolated between 2009 and 2013 on EHLY agar from less than 2 month-old diarrhoeic calves with a triplex PCR targeting the stx1, stx2, eae virulence genes; (ii) to serotype the positive isolates with PCR targeting the genes coding for ten most frequent and pathogenic human and calf STEC O serogroups; and (iii) to compare the MLSTypes and virulotypes of calf and human O5 AE-STEC after Whole Genome Sequencing using two server databases (www.genomicepidemiology.org). Of 233 isolates, 206 were triplex PCR-positive: 119 AE-STEC (58%), 78 EPEC (38%) and 9 STEC (4%); and the stx1+eae+ AE-STEC (49.5%) were the most frequent. Of them, 120 isolates (84% of AE-STEC, 23% of EPEC, 22% of STEC) tested positive with one O serogroup PCR: 57 for O26 (47.5%), 36 for O111 (30%), 10 for O103 (8%) and 8 for O5 (7%) serogroups. The analysis of the draft sequences of 15 O5 AE-STEC could not identify any difference correlated to the host. As a conclusion, (i) the AE-STEC associated with diarrhoea in young calves still belong to the same serogroups as previously (O5, O26, O111) but the O103 serogroup may be emerging, (ii) the O5 AE-STEC from calves and humans are genetically similar [less ▲]

Detailed reference viewed: 20 (8 ULg)
Full Text
Peer Reviewed
See detailNo favorable effect of reduced tillage on microbial community diversity in a silty loam soil (Belgium)
Degrune, Florine ULg; Theodorakopoulos, Nicolas ULg; Dufrêne, Marc ULg et al

in Agriculture, Ecosystems & Environment (2016), 224

Among the soil management practices used to promote sustainable agriculture, reduced tillage and retention of residues from the previous crop are reported to enhance significantly both soil fertility and ... [more ▼]

Among the soil management practices used to promote sustainable agriculture, reduced tillage and retention of residues from the previous crop are reported to enhance significantly both soil fertility and crop productivity. Here, high-throughput sequencing (454 technology) was used to see how the tillage regime (conventional vs. reduced tillage) and the fate of crop residues (retention or removal) affect microbial communities at two sampling depths (top soil: 0–5 cm and deeper soil: 15–20 cm) in a fertile silty loam soil in Belgium. All combinations of these three factors were studied. After 6 years of conversion from conventional to reduced tillage, depth emerged as the main factor responsible for variation in microbial diversity, tillage regime ranked second, and finally, crop residue fate had no influence on microbial diversity. For both bacteria and fungi, the diversity appeared higher in the top soil than in the deeper soil, and surprisingly, higher under conventional than under reduced tillage. These differences are explained by changes in community composition due to taxon loss rather than taxon replacement. The specific local set of environmental conditions (a loess-derived soil and an oceanic temperate climate) may explain these results. These observations raise the question: does impoverishment in indicator taxa influence soil processes, and thus crop production? To answer this question, we discuss how the presence of certain indicator taxa liable to play an ecological role might relate to crop productivity. [less ▲]

Detailed reference viewed: 55 (29 ULg)
Full Text
Peer Reviewed
See detailGrowth and Freeze-Drying Optimization of Bifidobacterium crudilactis
Tanimomo, Jean; Delcenserie, Véronique ULg; Taminiau, Bernard ULg et al

in Food and Nutrition Sciences (2016), 7

Bifidobacterium crudilactis FR62/b/3 belongs to a new population of bifidobacteria isolated from raw milk and raw milk cheese. The objective of this work was to study the large scale culture of the stain ... [more ▼]

Bifidobacterium crudilactis FR62/b/3 belongs to a new population of bifidobacteria isolated from raw milk and raw milk cheese. The objective of this work was to study the large scale culture of the stain and its stability in a dry formulation. Growth rate of Bifidobacterium crudilactis FR62/b/3 was optimal at a pH of 5.0 and a temperature of 37˚C. At a temperature growth of 33˚C and a pH of 5.0, the stationary phase was reached after 22 h, the viable cell number and the mean dry biomass concentration were respectively of 8.3 × 109 CFU/mL and of 2.1 g/L. Resistance of Bifidobacterium crudilactis FR62/b/3 to freeze-drying and effect of a variety of cryoprotectants to maintain the viability were also evaluated. Sorbitol was the most suitable cryoprotectant for freeze-drying as well as storage whereas sucrose and monosodium glutamate were only efficient during storage. [less ▲]

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailIntestinal Sucrase as a Novel Target Contributing to the Regulation of Glycemia by Prebiotics.
Neyrinck, Audrey M.; Pachikian, Barbara; Taminiau, Bernard ULg et al

in PLoS ONE (2016), 11(8),

Inulin-type fructans (ITF) are known for their capacity to modulate gut microbiota, energy metabolism and to improve glycemia in several animal models of obesity, and in humans. The potential contribution ... [more ▼]

Inulin-type fructans (ITF) are known for their capacity to modulate gut microbiota, energy metabolism and to improve glycemia in several animal models of obesity, and in humans. The potential contribution of ITF as modulators of sugar digestion by host enzymes has not been evaluated yet. A sucrose challenge has been performed on naive mice fed a standard diet supplemented with or without native chicory inulin (Fibruline 5%) for 3 weeks. The area under the curve of glycemia as well as sucrase activity in the small intestine were lowered after inulin treatment. Pyrosequencing of the 16S rRNA gene confirmed important changes in gut microbiota (mostly in favor of Blautia genus) due to inulin extract supplementation. Interestingly, the suppressive effect of inulin extract on postprandial glycemia also occurred when inulin was directly added to the sucrose solution, suggesting that the effect on sucrose digestion did not require chronic inulin administration. In vitro tests confirmed a direct inhibition of sucrase enzyme by the inulin extract, thereby suggesting that native chicory inulin, in addition to its well-known prebiotic effect, is also able to decrease the digestibility of carbohydrates, a phenomenon that can contribute in the control of post prandial glycemia. We may not exclude that the sucrose escaping the digestion could also contribute to the changes in the gut microbiota after a chronic treatment with inulin. [less ▲]

Detailed reference viewed: 13 (5 ULg)
Full Text
Peer Reviewed
See detailIn vitro screening of mare's milk antimicrobial effect and antiproliverative activity.
Guri, Anilda; Paligot, Michèle; Crevecoeur, Sébastien ULg et al

in FEMS Microbiology Letters (2016), 363(2), 1-7

The aims of this study were to examine the effect of mare's milk on virulence gene expression of Salmonella Typhimurium and observe its potential activity on proliferation of adenocarcinoma Caco-2 cells ... [more ▼]

The aims of this study were to examine the effect of mare's milk on virulence gene expression of Salmonella Typhimurium and observe its potential activity on proliferation of adenocarcinoma Caco-2 cells. Different supernatants of mare's milk, raw or heat-treated at 65°C for 15 s or 30 min, were studied. The changes in hilA gene expression of Salmonella Typhimurium in presence of mare's milk supernatants were assessed using a reporter luminescent strain. A significant decrease in hilA gene expression was observed with all tested supernatants. Virulence gene expression was then assessed using qPCR on a wild-type strain of Salmonella Typhimurium. A significant decrease of hilA and ssrB2 gene expression was observed with raw milk supernatants but not with heat-treated supernatants. The same supernatants were administered to Caco-2 cells to measure their proliferation rate. A significant reduction of proliferative effect was observed only with raw milk supernatants. This study reports that raw mare's milk was able to modulate virulence gene expression of Salmonella Typhimurium and exerts antiproliferative effects on Caco-2 cells. These results may offer new approaches for promoting gastrointestinal health. [less ▲]

Detailed reference viewed: 17 (6 ULg)
Full Text
Peer Reviewed
See detailClostridium difficile infection: Early history, diagnosis and molecular strain typing methods.
Rodriguez Diaz, Cristina ULg; Van Broeck, Johan; Taminiau, Bernard ULg et al

in Microbial Pathogenesis (2016), 97

Recognised as the leading cause of nosocomial antibiotic-associated diarrhoea, the incidence of Clostridium difficile infection (CDI) remains high despite efforts to improve prevention and reduce the ... [more ▼]

Recognised as the leading cause of nosocomial antibiotic-associated diarrhoea, the incidence of Clostridium difficile infection (CDI) remains high despite efforts to improve prevention and reduce the spread of the bacterium in healthcare settings. In the last decade, many studies have focused on the epidemiology and rapid diagnosis of CDI. In addition, different typing methods have been developed for epidemiological studies. This review explores the history of C. difficile and the current scope of the infection. The variety of available laboratory tests for CDI diagnosis and strain typing methods are also examined. [less ▲]

Detailed reference viewed: 11 (3 ULg)
Full Text
Peer Reviewed
See detailStudy of the Potential Zoonotic Transmission of Clostridium difficile in Belgian Cattle Farms.
Rodriguez Diaz, Cristina ULg; Hakimi, Djalal-Eddine; Daube, Georges ULg et al

in Journal of Food Protection (2016), 79(supplement A),

Introduction: Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test ... [more ▼]

Introduction: Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test positive for the bacterium, it seems plausible that C. difficile could be zoonotic. A former study showed that the prevalence in veal calf aged less than 6 months was 22% while in adult cattle population, it was 6,9 %. Purpose: This study aimed to determine the prevalence and the epidemiology of C. difficile in cattle farms and the possible spread of the bacterium among animals and farmers. Methods: A total of 176 faecal samples of cattle were collected from 5 different Belgian farms (south East Belgium), from November 2015 to February 2016. A stool sample of each farmer was also requested. Detection of C. difficile was performed by classical culture on C. difficile selective medium (cycloserine cefoxitin fructose cholate). Isolates were characterised by PCR-ribotyping and Genotype Cdiff test (Hain Lifescience), which allows the detection of all toxin genes, mutations in gyrA gene and the deletion in the regulator gene tcdC. Toxic activity was confirmed by a cytotoxic assay on MRC-5 cells. Results: C. difficile was detected in 14/178 (7.9%) animal samples. Isolates were grouped into five different types, including PCR-ribotype 015 (this ribotype is one the most encountered in hospitals in Belgium). The other types were UCL46A, UCL24*, UCL24, UCL33. All of them were identified as toxigenic by cytotoxicity assay and toxin genes profile. In contrast, none of the 5 farmers studied were positive for the bacterium. Significance: Results obtained indicate that PCR-ribotypes commonly isolated from hospitalised patients are also present in cattle, indicating an animal reservoir. However, a zoonotic transmission could be not demonstrated in this preliminary study. [less ▲]

Detailed reference viewed: 15 (3 ULg)
Full Text
Peer Reviewed
See detailUse of the potential probiotic strain Lactobacillus salivarius SMXD51 to control Campylobacter jejuni in broilers.
Saint-Cyr, Manuel Jimmy; Haddad, Nabila; Taminiau, Bernard ULg et al

in International Journal of Food Microbiology (2016)

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 ▲]

Detailed reference viewed: 9 (3 ULg)
Full Text
See detailRecommandations relatives à l’usage de lait maternel cru pour les prématurés hospitalisés en Néonatologie - Administration du lait de la mère à son propre enfant - Avis 8734
Brasseur, Daniel; Rigo, Jacques ULg; Melin, Pierrette ULg et al

Book published by Conseil Supérieur de la Santé (2016)

De nombreuses études ont démontré l’intérêt pour les prématurés de faible poids à la naissance d’une alimentation exclusive au LM qui diminue significativement la mortalité et la morbidité néonatale. Elle ... [more ▼]

De nombreuses études ont démontré l’intérêt pour les prématurés de faible poids à la naissance d’une alimentation exclusive au LM qui diminue significativement la mortalité et la morbidité néonatale. Elle offre également des avantages à moyen et à long terme tant sur le plan de la santé physique que du développement psychomoteur et cognitif de ces enfants. Dans ce sens, le lait de la mère pour son propre enfant constitue le lait de référence pour l’alimentation du prématuré, qu’il soit frais, congelé voire pasteurisé (AAP, 2012). L’utilisation de lait de don, nécessairement pasteurisé, n’a de sens qu’en cas d’indisponibilité complète ou partielle du lait de la propre mère et s’utilise principalement pendant les premières semaines de vie. Les risques éventuels (bactériologique, virologique et nutritionnel) qui imposent d’émettre des recommandations pour l'utilisation du lait de la propre mère dans les unités néonatales sont décrits dans les paragraphes suivants du présent document. [less ▲]

Detailed reference viewed: 19 (2 ULg)
Full Text
Peer Reviewed
See detailRhubarb extract prevents hepatic inflammation induced by acute alcohol intake, an effect related to the modulation of the gut microbiota.
Neyrinck, Audrey M.; Etxeberria, Usune; Taminiau, Bernard ULg et al

in Molecular Nutrition & Food Research (2016)

SCOPE: Binge consumption of alcohol is an alarming global health problem. Acute ethanol intoxication is characterized by inflammation and oxidative stress, which could be promoted by gut barrier function ... [more ▼]

SCOPE: Binge consumption of alcohol is an alarming global health problem. Acute ethanol intoxication is characterized by inflammation and oxidative stress, which could be promoted by gut barrier function alterations. In this study, we have tested the hypothesis of the hepatoprotective effect of rhubarb extract in a mouse model of binge drinking and we explored the contribution of the gut microbiota in the related- metabolic effects. METHODS AND RESULTS: Mice were fed a control diet supplemented with or without 0.3% rhubarb extract for 17 days and were necropsied 6 hours after an alcohol challenge. Supplementation with rhubarb extract changed the microbial ecosystem (assessed by 16S rDNA pyrosequencing) in favor of Akkermansia muciniphila and Parabacteroides goldsteinii. Furthermore, it improved alcohol-induced hepatic injury, down-regulated key markers of both inflammatory and oxidative stresses in the liver tissue, without affecting significantly steatosis. In the gut, rhubarb supplementation increased crypt depth, tissue weight, the expression of antimicrobial peptides. CONCLUSIONS: These findings suggest that some bacterial genders involved in gut barrier function, are promoted by phytochemicals present in rhubarb extract, and could therefore be involved in the modulation of the susceptibility to hepatic diseases linked to acute alcohol consumption. This article is protected by copyright. All rights reserved. [less ▲]

Detailed reference viewed: 16 (3 ULg)
Full Text
Peer Reviewed
See detailFlow cytometry community fingerprinting and amplicon sequencing for the assessment of landfill leachate cellulolytic bioaugmentation
Kinet, Romain ULg; Dzaomuho, Phidias; Baert, Jonathan ULg et al

in Bioresource Technology (2016)

Flow cytometry (FCM) is a high throughput single cell technology that is actually becoming widely used for studying phenotypic and genotypic diversity among microbial communities. This technology is ... [more ▼]

Flow cytometry (FCM) is a high throughput single cell technology that is actually becoming widely used for studying phenotypic and genotypic diversity among microbial communities. This technology is considered in this work for the assessment of a bioaugmentation treatment in order to enhance cellulolytic potential of landfill leachate. The experimental results reveal the relevant increase of leachate cellulolytic potential due to bioaugmentation. Cytometric monitoring of microbial dynamics along these assays is then realized. The Flow FP package is used to establish microbial samples fingerprint from initial 2D cytometry histograms. This procedure allows highlighting microbial communities' variation along the assays. Cytometric and 16S rRNA gene sequencing fingerprinting methods are then compared. The two approaches give same evidence about microbial dynamics throughout digestion assay. There are however a lack of significant correlation between cytometric and amplicon sequencing fingerprint at genus or species level. Same phenotypical profiles of microbiota during assays matched to several 16S rRNA gene sequencing ones. Flow cytometry fingerprinting can thus be considered as a promising routine on-site method suitable for the detection of stability/variation/disturbance of complex microbial communities involved in bioprocesses. [less ▲]

Detailed reference viewed: 32 (10 ULg)
Full Text
Peer Reviewed
See detailAdding mucins to an in vitro batch fermentation model of the large intestine induces changes in microbial population isolated from porcine feces depending on the substrate
Tran, Thi Hanh Tham ULg; Boudry, Christelle ULg; Everaert, Nadia ULg et al

in FEMS Microbiology Ecology (2016), 92(2), 13

Adding mucus to in vitro fermentation models of the large intestine showed that some genera, namely lactobacilli, are dependent on host-microbiota interactions and that they rely on mucosa layers to ... [more ▼]

Adding mucus to in vitro fermentation models of the large intestine showed that some genera, namely lactobacilli, are dependent on host-microbiota interactions and that they rely on mucosa layers to increase their activity. This study investigates whether this dependence on mucus is substrate-dependent and to which extend other genera are impacted by the presence of mucus. Inulin and cellulose were fermented in vitro by a fecal inoculum from pig in the presence or not of mucin-beads in order to compare fermentation patterns and bacterial communities. Mucins increased final gas production with inulin and shifted short-chain fatty acids molar ratios (P<0.001). QPCR analyses revealed that Lactobacillus spp. and Bifidobacterium spp. decreased with mucins, but Bacteroides spp. increased when inulin was fermented. A more in-depth community analysis indicated that the mucins increased Proteobacteria (0.55 vs. 0.25 %, P=0.013), Verrucomicrobia (5.25 vs. 0.03 %, P=0.032), Ruminococcaceae, Bacteroidaceae, and Akkermansia spp.. Proteobacteria (5.67 vs. 0.55 %, P<0.001) and Lachnospiraceae (33 vs. 10.4 %) were promoted in the mucuscompared to the broth, while Ruminococcaceae decreased. The introduction of mucins affected many microbial genera and fermentation patterns, but from PCA results, the impact of mucus was independent from the fermentation substrate. [less ▲]

Detailed reference viewed: 125 (22 ULg)
Full Text
Peer Reviewed
See detailExploring the bacterial diversity of Belgian steak tartare using metagenetics and qPCR analysis
Delhalle, Laurent ULg; Korsak Koulagenko, Nicolas ULg; Taminiau, Bernard ULg et al

in Journal of Food Protection (2016), 79(2), 200-229

Steak tartare is a popular meat dish in Belgium. It is prepared with raw ground minced beef and eaten with sauce, vegetables, and spiced. Since it contains raw meat, steak tartare is highly prone to ... [more ▼]

Steak tartare is a popular meat dish in Belgium. It is prepared with raw ground minced beef and eaten with sauce, vegetables, and spiced. Since it contains raw meat, steak tartare is highly prone to bacterial spoilage. The objective of this study was to explore the bacterial flora diversity in steak tartare in Belgium according to the source and to determine which bacteria are able to grow during the shelf life. A total of 58 samples from butchers’ shops, restaurants, sandwich shops and supermarkets were collected. These samples were analyzed using 16S rDNA metagenetics, a classical microbiological technique, and quantitative real-time PCR (qPCR) targeting the Lactobacillus genus. Samples were analyzed at the beginning and at the end of their shelf life, except for those from restaurants and sandwich shops analyzed only at the purchase date. Metagenetic analysis identified up to 180 bacterial species and 90 genera in some samples. But only seven bacterial species were predominant in the samples, depending on the source: Brochothrix thermosphacta, Lactobacillus algidus, Lactococcus piscium, Leuconostoc gelidum, Photobacterium kishitani, Pseudomonas spp. and Xanthomonas oryzae. With this work, an alternative method is proposed to evaluate the total flora in food samples based on the number of reads from metagenetic analysis and the results of qPCR. The degree of underestimation of aerobic plate counts (APCs) at 30°C estimated with the classical microbiology method was demonstrated in comparison with the proposed culture independent method. Compared to culture-based methods, metagenetic analysis combined with qPCR targeting Lactobacillus provides valuable information for characterizing the bacterial flora of raw meat. [less ▲]

Detailed reference viewed: 211 (38 ULg)
Full Text
See detailSensory quality of beef patties inoculated with strains of Carnobacterium maltaromaticum with potential as biopreservatives
Didimo Imazaki, Pedro Henrique ULg; Jacques-Houssa, Charlotte ULg; Kergourlay, Gilles ULg et al

Conference (2015, December 02)

Biopreservation is the use of naturally occurring microorganisms and/or their inherent antimicrobial compounds to extend shelf life and to enhance the safety of foods. The aim of the present study was to ... [more ▼]

Biopreservation is the use of naturally occurring microorganisms and/or their inherent antimicrobial compounds to extend shelf life and to enhance the safety of foods. The aim of the present study was to perform a sensory evaluation of beef patties inoculated with potentially biopreservative strains of Carnobacterium maltaromaticum. Three different strains of C. maltaromaticum (lab. ref.: CM_824, CM_827 and CM_829) isolated from vacuum packaged beef with long shelf life were selected for this study. An untrained panel was requested to make a sensory evaluation of raw and cooked beef patties 8 and 10 days after inoculation with the selected strains at 104 and 106 UFC/g and storage in high-O2 atmosphere. After 8 days of storage, non inoculated samples (blank) were perceived as having the best studied sensory descriptors. The samples inoculated with strain CM_827 had a sensory quality very close to the blank. After 10 days of storage, samples inoculated with the strain CM_827 at 104 UFC/g received the highest scores for appearance and color. This study permitted to evaluate the effect of three C. maltaromaticum strains on the sensory quality of beef patties. Strain CM_827 did practically not change the sensory attributes of beef patties. Samples inoculated with strain CM_824 and CM_829 received the worst scores for several of the tested descriptors. Therefore, further research on the biopreservative capacity of C. maltaromaticum should be conducted with strain CM_827. [less ▲]

Detailed reference viewed: 17 (4 ULg)