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See detailThe use of 16S rRNA gene metagenetic monitoring of refrigerated food products for understanding the kinetics of microbial subpopulations at different storage temperatures: the example of white pudding
Cauchie, Emilie ULg; Gand, Mathieu; Kergourlay, Gilles ULg et al

in International Journal of Food Microbiology (in press)

In order to control food losses and wastage,monitoring the microbial diversity of food products, during processing and storage is important, as studies have highlighted the metabolic activities of ... [more ▼]

In order to control food losses and wastage,monitoring the microbial diversity of food products, during processing and storage is important, as studies have highlighted the metabolic activities of somemicroorganismswhich can lead to spoilage. Knowledge of this diversity can be greatly improved by using a metagenetic approach based on high throughput 16S rRNA gene sequencing, which enables a much higher resolution than culture-based methods. Moreover, the Jameson effect, a phenomenon described by Jameson in 1962, is often used to classify bacterial strains within an ecosystem. According to this, we have studied the bacterial microbiota of Belgian white pudding during storage at different temperatures using culture-dependent and independent methods. The product was inoculated with a mix of dominant strains previously isolated from this foodstuff at the end of its shelf life (Carnobacterium maltaromaticum, Lactobacillus fuchuensis, Lactobacillus graminis, Lactobacillus oligofermentans, Lactococcus lactis, Leuconostoc mesenteroides, Raoultella terrigena and Serratia sp.). Daily during 16 days, the absolute abundance of inoculated strain was monitored by combining total count on plate agar and metagenetic analysis. The resultswere confirmed by qPCR analysis. The growth of each specieswasmodelled for each temperature conditions, representative of good or bad storage practices. These data allowed the bacterial strains subdivision into three classes based on criteria of growth parameters for the studied temperature: the “dominant”, the “subdominant” and the “inhibited” bacterial species, according to their maximal concentration (Nmax, log CFU/g), growth rate (μmax, 1/h) and time to reach the stationary phase (TRSP, days). Thereby, depending on the storage conditions, these data have permitted to follow intrinsically the evolution of each strain on the bacterial ecosystemof Belgianwhite pudding. Interestingly, it has shown that the reliability of the Jameson effect can be discussed. For example, at 4 °C when Lactococcus lactis and Serratia sp. stopped growth at day 12, at the same time Carnobacterium maltaromaticum reached its maximal concentration and entered its stationary phase. In opposition to this, it can be noticed that in the same condition, the “sub-dominant” organisms continued their growth independently of the “dominant” species behaviour. In this case, the Jameson effect was not illustrated. This pattern is described for all storage conditions with the same strain classifications. These results highlighted the importance of combining metagenetic analysis and classical methods, with modelling, to offer a new tool for studying the evolution ofmicroorganisms present in perishable foodwithin different environmental conditions. [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 ULg; Taminiau, Bernard ULg; Nezer, Carine et al

in Archives of Virology (in press)

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 a metagenetic approach to monitor the bacterial microbiota of “Tomme d’Orchies” cheese during the ripening process
Ceugniez, Alexandre; Taminiau, Bernard ULg; Coucheney, Françoise et al

in International Journal of Food Microbiology (in press)

The study of microbial ecosystems in artisanal foodstuffs is important to complete in order to unveil its diversity. The number of studies performed on dairy products has increased during the last decade ... [more ▼]

The study of microbial ecosystems in artisanal foodstuffs is important to complete in order to unveil its diversity. The number of studies performed on dairy products has increased during the last decade, particularly those performed on milk and cheese derivative products. In this work, we investigated the bacterial content of "Tomme d'Orchies" cheese, an artisanal pressed and uncooked French cheese. To this end, a metagenetic analysis, using Illumina technology, was utilized on samples taken from the surface and core of the cheese at 0, 1, 3, 14 and 21 days of ripening process. In addition to the classical microbiota found in cheese, various strains likely from environmental origin were identified. A large difference between the surface and the core content was observed within samples withdrawn during the ripening process. The main species encountered in the core of the cheese were Lactococcus spp. and Streptococcus spp., with an inversion of this ratio during the ripening process. Less than 2.5% of the whole population was composed of strains issued from environmental origin, as Lactobacillales, Corynebacterium and Brevibacterium. In the core, about 85% of the microbiota was attributed to the starters used for the cheese making. In turn, the microbiota of the surface contained less than 30% of these starters and interestingly displayed more diversity. The predominant genus was Corynebacterium sp., likely originating from the environment. The less abundant microbiota of the surface was composed of Bifidobacteria, Brevibacterium and Micrococcales. To summarize, the “Tomme d’Orchies” cheese displayed a high diversity of bacterial species, especially on the surface, and this diversity is assumed to arise from the production environment and subsequent ripening process. [less ▲]

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See detailDetection, isolation and characterization of Fusobacterium gastrosuis sp. nov. colonizing the stomach of pigs
De Witte, C.; Flahou, B.; Ducatelle, R. et al

in Systematic & Applied Microbiology (in press)

Nine strains of a novel Fusobacterium sp. were isolated from the stomach of 6-8 months old and adult pigs. The isolates were obligately anaerobic, although they endured 2 hours exposure to air ... [more ▼]

Nine strains of a novel Fusobacterium sp. were isolated from the stomach of 6-8 months old and adult pigs. The isolates were obligately anaerobic, although they endured 2 hours exposure to air. Phylogenetic analysis based on 16S rRNA and gyrase B genes demonstrated that the isolates showed high sequence similarity with Fusobacterium mortiferum, Fusobacterium ulcerans, Fusobacterium varium, Fusobacterium russii and Fusobacterium necrogenes, but formed a distinct lineage in the genus Fusobacterium. Comparative analysis of the genome of the type strain of this novel Fusobacterium sp. confirmed that it is different from other recognized Fusobacterium spp. DNA-DNA hybridization, fingerprinting and genomic %GC determination further supported the conclusion that the isolates belong to a new, distinct species. The isolates were also distinguishable from these and other Fusobacterium spp. by phenotypical characterization. The strains produced indole and exhibited proline arylamidase and glutamic acid decarboxylase activity. They did not hydrolyse esculin, did not exhibit pyroglutamic acid arylamidase, valine arylamidase, α-galactosidase, β-galactosidase, β-galactosidase-6-phosphate or α-glucosidase activity nor produced acid from cellobiose, glucose, lactose, mannitol, mannose, maltose, raffinose, saccharose, salicin or trehalose. The major fatty acids were C16 : 0 and C18 : 1ω9c. The name Fusobacterium gastrosuis sp. nov. is proposed for the novel isolates with the type strain CDW1(T) (= DSM 101753(T) = LMG 29236(T)). We also demonstrated that Clostridium rectum and Fusobacterium mortiferum represent the same species, with nomenclatural priority for the latter. [less ▲]

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See detailIdentification of bacterial strains isolated from the traditional date product "Btana" produced in south regions of Algeria
Abekhti, Abdelkader; Taminiau, Bernard ULg; Kihal, Mabrouk et al

in Folia Microbiologica (in press)

Eleven samples of the traditional date product " Btana" prepared by direct (DBM) and indirect method (UBM) were analysed to characterize their bacterial diversity. A total of 42 representative isolates ... [more ▼]

Eleven samples of the traditional date product " Btana" prepared by direct (DBM) and indirect method (UBM) were analysed to characterize their bacterial diversity. A total of 42 representative isolates have been chosen for molecular identification. 16S rRNA gene sequencing revealed the presence of 20 species within 30.9% belonged to the genus Bacillus, 28.6% of the Staphylococcus, and Enterococcus genus. Within the minority represented species, two isolates were identified as Paenibacillus (isolated from UBM exclusively), Streptococci salivarius, Lactobacillus sakei and Klebsiella pneumoniae. Preliminary results indicate that IBM is more selective for spore former bacilli contrary to DBM that show more diversity in the bacterial flora with a prevalence of Enterococcus. API ZYM test showed that the bacilli species have a weak hydrolase activity. [less ▲]

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See detailAssessment of bacterial superficial contamination in classical or ritually slaughtered cattle using metagenetics and microbiological analysis
Korsak Koulagenko, Nicolas ULg; Taminiau, Bernard ULg; Hupperts, Caroline et al

in International Journal of Food Microbiology (in press)

The aim of this study was to investigate the influence of the slaughter technique (Halal vs. Classical slaughter) on the superficial contamination of cattle carcasses, by using traditional microbiological ... [more ▼]

The aim of this study was to investigate the influence of the slaughter technique (Halal vs. Classical slaughter) on the superficial contamination of cattle carcasses, by using traditional microbiological procedures and 16S rDNA metagenetics. The purpose was also to investigate the neck area to identify bacteria originating from the digestive or the respiratory tract. Twenty bovine carcasses (10 from each group) were swabbed at the slaughterhouse, where both slaughtering methods are practiced. Two swabbing areas were chosen: one “legal” zone of 1,600 cm2 (composed of zones from rump, flank, brisket and forelimb) and locally on the neck area (200 cm2). Samples were submitted to classical microbiology for aerobic Total Viable Counts (TVC) at 30°C and Enterobacteriaceae counts, while metagenetic analysis was performed on the same samples. The classical microbiological results revealed no significant differences between both slaughtering practices; with values between 3.95 and 4.87 log CFU/100 cm2 and 0.49 and 1.94 log CFU/100 cm2, for TVC and Enterobacteriaceae respectively. Analysis of pyrosequencing data showed that differences in the bacterial population abundance between slaughtering methods were mainly observed in the “legal” swabbing zone compared to the neck area. Bacterial genera belonging to the Actinobacteria phylum were more abundant in the “legal” swabbing zone in “Halal” samples, while Brevibacterium and Corynebacterium were encountered more in “Halal” samples, in all swabbing areas. This was also the case for Firmicutes bacterial populations (families of Aerococcaceae, Planococcaceae). Except for Planococcoceae, the analysis of Operational Taxonomic Unit (OTU) abundances of bacteria from the digestive or respiratory tract revealed no differences between 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 of taxonomy at the genus level taxonomy highlights differences between swabbing areas. Although not clearly proven in this study, differences in hygiene practices used during both slaughtering protocols could explain the differences in contamination between carcasses from both slaughtering groups. [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 ULg; Benmedjadi, Soumaya; Blaszczyk, Marie et al

Poster (2016, October 21)

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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 ULg; Cauchie, Emilie ULg; Leenders, Justine ULg 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 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 ▲]

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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 ▲]

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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 ▲]

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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), 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 ▲]

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See detailClostridium difficile in Food and Animals: A Comprehensive Review.
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Van Broeck, J. et al

in Advances in Experimental Medicine and Biology (2016)

Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment ... [more ▼]

Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present. [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), 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 ▲]

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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 ▲]

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