References of "Daube, Georges"
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See detailLaboratory idenification 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 ▲]

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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 ▲]

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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 ▲]

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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)

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 ▲]

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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)

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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 ▲]

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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 ▲]

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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 ▲]

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See detailNo favorable effect of reduced tillage on microbial communities in a silty loam soil (Belgium)
Degrune, Florine ULg; Theodorakopoulos, Nicolas ULg; Dufrêne, Marc ULg et al

Poster (2015, December 01)

To date, only a few studies have applied metagenomics to investigate the influence of different tillage regimes and types of crop residue management on soil microbial communities. These studies were ... [more ▼]

To date, only a few studies have applied metagenomics to investigate the influence of different tillage regimes and types of crop residue management on soil microbial communities. These studies were conducted under specific climates on soils characterized by particular land-use histories. A very different ecological context is to be found in certain areas of Western Europe, such as central Belgium, whose loess-derived soils are among the most fertile in the world and have long been used for intensive agriculture. Specific objectives were to determine diversity levels and changes in microbial community composition under different combinations of tillage regime (conventional vs. reduced) and crop residue fate (residue removal R- vs. residues left R+ on the field). As reduced tillage results in two contrasting zones (the first centimeters of soil are mixed each year, while the soil below remains unperturbed), we chose to perform the analysis at two depths: 0 to 5 cm and 15 to 20 cm. [less ▲]

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See detailEvaluation of the sensory quality of beef patties inoculated with Carnobacterium maltaromaticum strains with biopreservative potential
Didimo Imazaki, Pedro Henrique ULg; Jacques-Houssa, Charlotte ULg; Kergourlay, Gilles ULg et al

Conference (2015, October 16)

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 ▲]

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See detailFaecal microbiota characterisation of horses using 16 rdna barcoded pyrosequencing, and carriage rate of clostridium difficile at hospital admission
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Brévers, Bastien et al

in BMC Microbiology (2015), 15

Background The equine faecal microbiota is very complex and remains largely unknown, while interspecies interactions have an important contribution to animal health. Clostridium difficile has been ... [more ▼]

Background The equine faecal microbiota is very complex and remains largely unknown, while interspecies interactions have an important contribution to animal health. Clostridium difficile has been identified as an important cause of diarrhoea in horses. This study provides further information on the nature of the bacterial communities present in horses developing an episode of diarrhoea. The prevalence of C. difficile in hospitalised horses at the time of admission is also reported. Results Bacterial diversity of the gut microbiota in diarrhoea is lower than that in non-diarrhoeic horses in terms of species richness (p-value <0.002) and in population evenness (p-value: 0.02). Statistical differences for Actinobacillus, Porphyromonas, RC9 group, Roseburia and Ruminococcaceae were revealed. Fusobacteria was found in horses with diarrhoea but not in any of the horses with non-diarrheic faeces. In contrast, Akkermansia was among the three predominant taxa in all of the horses studied. The overall prevalence of C. difficile in the total samples of hospitalised horses at admission was 3.7 % (5/134), with five different PCR-ribotypes identified, including PCR-ribotype 014. Two colonised horses displayed a decreased bacterial species richness compared to the remaining subjects studied, which shared the same Bacteroides genus. However, none of the positive animals had diarrhoea at the moment of sampling. Conclusions The abundance of some taxa in the faecal microbiota of diarrhoeic horses can be a result of microbiome dysbiosis, and therefore a cause of intestinal disease, or some of these taxa may act as equine enteric pathogens. Clostridium difficile colonisation seems to be transient in all of the horses studied, without overgrowth to trigger infection. A large proportion of the sequences were unclassified, showing the complexity of horses’ faecal microbiota. [less ▲]

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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

Poster (2015, August)

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 strains of C. maltaromaticum with potential as biopreservatives. Three different strains of C. maltaromaticum (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. This preliminary 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 ▲]

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See detailMetagenomic analysis of samples
Daube, Georges ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Patent (2015)

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See detailMethod of testing for animal-derived ingredients in foods
Daube, Georges ULg; Burteau, Sophie; Nezer, Carine et al

Patent (2015)

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See detailMorphological and functional characterization of Carnobacterium maltaromaticum isolated from vacuum-packed beef with long shelf life
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Ndedi Ekolo, François ULg et al

Poster (2015, June 17)

Temperatures near the freezing point of meat (−1.5 °C), associated with vacuum packaging, allows the preservation of this product up to several months, which makes possible the meat trade across the ... [more ▼]

Temperatures near the freezing point of meat (−1.5 °C), associated with vacuum packaging, allows the preservation of this product up to several months, which makes possible the meat trade across the planet without resorting to freezing. Other the type of packaging and the storage temperature, the shelf-life of meat is directly related to its initial microbiological ecosystem and its evolution. Carnobacterium maltaromaticum is a lactic acid bacterium, and many lactic acid bacteria associated with meat are known for their bactericidal or bacteriostatic activity against other strains, species or genera of bacteria. In this way, the presence of certain lactic acid bacteria adapted to a low temperature in fresh meat could extend the shelf life and improve the microbial stability and safety of this product. The aim of this study was to perform a morphological and functional characterization of a C. maltaromaticum strain (lab. ref. CFAUS2/DLC/4/E1) with potential bioprotective effect isolated from commercial vacuum packaged long shelf life beef. The morphological, biochemical and enzymatic profiles, the influence of different temperatures and atmospheres, and the microbial stability of fresh beef inoculated with the C. maltaromaticum strain were evaluated. Morphological, biochemical and enzymatic profiles of the isolated C. maltaromaticum strain were similar to those of two reference strains (LMG 11393 and LMG 22902). The evaluation of the influence of different atmospheres showed that the growth of C. maltaromaticum was the slowest in an atmosphere containing 70 % O2 and 30 % CO2. Vacuum packaging is therefore more suitable for the growth of this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat. The functional characterization of this strain will be further pursued by genotypic characterization and its potential bioprotective effect will also be studied. [less ▲]

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See detailUse of 16S rDNA Metagenetics and classical Microbiology to Assess the bacterial superficial Contamination Patterns in Bovines Classically Slaughtered or following the Halal Ritual
Korsak Koulagenko, Nicolas ULg; Taminiau, Bernard ULg; Hupperts, Caroline et al

Poster (2015, June 17)

In Belgium and in several European countries, two cattle slaughtering protocols exist: the classical method, that encompasses a stunning step before the sticking procedure, and the halal method, combining ... [more ▼]

In Belgium and in several European countries, two cattle slaughtering protocols exist: the classical method, that encompasses a stunning step before the sticking procedure, and the halal method, combining the stunning and the sticking in one single step. The main difference lies in the fact that, in the halal protocol, a single cut with a sharp knife is practiced directly on live cattle, instead of two cutting steps with two different knives for the sticking in the classical slaughtering technique. The unique section in the halal technique results generally in the cross section of trachea and esophagus of cattle. The aim of this study was to seek if the two slaughtering techniques were similar regarding the superficial contamination of carcasses, swabbed between 2 and 4 hours after the killing step. For this purpose, classical microbiological tests (TVC and Enterobacteriaceae) and 16S rDNA metagenetic analysis were carried out from 20 cattle carcasses (swabbing of “legal” zone – 1.600 cm2 – and in the neck area – 200 cm2). The classical microbiological results revealed no significant differences between the two slaughtering practices. Statistical analysis of pyrosequencing data showed that differences in bacterial population abundance between slaughtering methods were mainly found in the “legal” swabbing zone compared to the neck area. Bacterial genera belonging to Actinobacteria (Brevibacterium, Corynebacterium) were more aundant in “Halal” samples whereas populations from the Proteobacteria (Caulobacteraceae, Comamonadaceae, Bradyrhizobiaceae) and Firmicutes (Lactobacillus) were more abundand in the “classical” group. The analysis of OTU abundance of bacteria from the digestive or respiratory tract revealed no differences beteween groups. In conclusion, the slaughtering method does not influence the superficial microbiological pattern in terms of specific microbiological markers of the digestive or respiratory tract. However, precise analysis to the genus level underlines differences between methods, the legal swabbing zone being still the best sampling zone compared to the neckline. The next step will be the identification of precise contamination origin of the differences found between slaughtering methods. [less ▲]

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