References of "Daube, Georges"
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See detailImpact of agricultural practices on soil microbial communities in Belgium
Degrune, Florine ULg; Taminiau, Bernard ULg; Dufrêne, Marc ULg et al

Poster (2013, December 11)

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on ... [more ▼]

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on finding ways to reduce the use of chemicals, and investigating microbial life may lead to solutions. We know that bacteria and fungi are deeply involved in nutrient cycles. Recently the emergence of massive parallel sequencing has enabled us to realize that microbial diversity is huger than we expected. With such a tool it should be possible to study how soil management practices affect the microbial diversity of agricultural soils. A few such studies have been conducted, most of them focusing on bacteria. For Belgium in particular, there is a lack of data on this topic. Here the aim was to see how residue management and tillage practices affect communities of both bacteria and fungi in Belgian agricultural soils. For this we used 454 pyrosequencing of 16S bacterial and 28S fungal rRNA genes. Soil samples came from an experiment in which faba beans were grown with four soil management practices (tillage and no tillage, with and without crop residues), each repeated four times in a Latin square. Several chemical and physical characteristics were measured on each sample. The results show that fungi and bacteria are both impacted by Tillage practices. The main soil drivers are Magnesium and Phosphorus for Fungi communities, and Phosphorus and Potassium for bacteria communities. Finally, the fungi variance observed between plots is explained at 38% by Tillage, Magnesium and phosphorus. And the bacteria variance is explained at 28% by Tillage, Phosphorus and Potassium. [less ▲]

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See detailEvaluation of the bacterial diversity and its evolution during storage of fresh beef from British and Belgian origins under different atmosphere and temperature conditions
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Taminiau, Bernard ULg et al

Conference (2013, December 10)

The purpose of this study was to evaluate the bacterial diversity and its evolution during storage of fresh beef, depending on its origin, packaging and storage temperature, by using a metagenomic ... [more ▼]

The purpose of this study was to evaluate the bacterial diversity and its evolution during storage of fresh beef, depending on its origin, packaging and storage temperature, by using a metagenomic approach. Metagenomic analyzes revealed that the origin, atmosphere and temperature conditions influenced the selection of the predominant flora. Vacuum-packaged British samples presented higher concentrations of Lactobacillus algidus at the begging of the experiment than Belgian samples. Furthermore, the development of Lactobacillus algidus was favored in British and Belgian samples preserved under vacuum at −1 °C, while a predominance of Lactococcus piscium was observed for samples stored at +4 °C. These microorganisms have already been isolated from beef, but taking into account that the knowledge about these two species is currently limited, it is still not possible to state if the conservability of the tested samples was influenced by the presence of these bacteria. Moreover, storage under modified atmosphere favored the development of Leuconostoc gasicomitatum in both British and Belgian samples. This specie is often associated with spoilage of cold-stored modified-atmosphere-packaged (MAP) nutrient-rich foods. This result can partially explain the short shelf-life of the samples once they are stored under this condition. Metagenomics showed to be a useful tool to study the microbial population of a complex matrix since some of the identified genera could not have grown or have grown slowly in culture media commonly used. In addition, it helped to clarify the evolution of the bacterial ecosystem associated to meat during its storage. [less ▲]

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See detailMicrobial, biochemical and sensorial quality assessment of Algerian farmed tilapia (Oreochromis niloticus) stored at 4 and 30°C
Dergal, Nadir; Abi-Ayad, S.M.E.-A.; Degand, Guy ULg et al

in African Journal of Food Science (2013), 7(12), 498-507

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See detailClostridium difficile: an emerging zoonotic pathogen ?
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Avesani, Véronique et al

Conference (2013, November 21)

Clostridium difficile is an anaerobic, spore-forming bacterium that remains the main cause of nosocomial diarrhoea in humans after use of antibiotics. C. difficile has also been described in other ... [more ▼]

Clostridium difficile is an anaerobic, spore-forming bacterium that remains the main cause of nosocomial diarrhoea in humans after use of antibiotics. C. difficile has also been described in other environments outside of hospitals, such as soil, river and seawater samples (Pasquale et al., 2011) and in animals, in which it can also cause enteric disease (Songer and Anderson, 2006). The possibility of transmission of C. difficile pathogenic isolates between animals, environments and humans has been suggested (Janezic et al., 2012). In recent years, the interest in C. difficile in food and in food animals has increased, leading to studying animals as a possible reservoir and a potential risk for food borne infections linked to C. difficile. Studies in various countries have determined differences in the prevalence of C. difficile in animals just before slaughter (Houser et al., 2012; Rodriguez et al., 2012) as well as in retail meat (Houser et al., 2012). In addition, many types, including PCR-ribotype 078, are present in humans, animals and meat (Janezic et al.; Weese et al., 2009). The objective of this study was to evaluate the presence of C. difficile at the slaughterhouse and in retail meat. Intestinal and carcass samples were collected from pigs and cattle at a single slaughterhouse. Raw meat (beef and pork) was obtained from the retail trade. C. difficile was isolated in 1% and 9.9% of the pig and cattle intestinal contents and in 7.9% and 7% of cattle and pig carcass samples respectively. From retail meat, C. difficile was recovered from 2.3% of the beef samples and from 4.7% of the pork samples. A total of 21 different PCR-ribotypes were identified with a large percentage of types 078 and 014. This study confirms that animals are carriers of C. difficile at slaughter, and that carcass contamination occurs inside the slaughterhouse. Furthermore the results obtained also reveal the presence of toxigenic C. difficile in retail meat in Belgium with a predominance of isolates correlated with the PCR-ribotypes involved in human C. difficile infections. [less ▲]

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See detailSe nourrir de microbes : la solution pour une bonne santé
Daube, Georges ULg

Conference given outside the academic context (2013)

L'humanité a longtemps payé un lourd tribu aux maladies infectieuses et notamment à celles transmises par l'alimentation ; le choléra, la fièvre typhoïde et la dysenterie n'en sont que trois exemples ... [more ▼]

L'humanité a longtemps payé un lourd tribu aux maladies infectieuses et notamment à celles transmises par l'alimentation ; le choléra, la fièvre typhoïde et la dysenterie n'en sont que trois exemples parmi les plus connus. C'est essentiellement l'hygiène qui a fait s'éloigner ces grands fléaux de nos sociétés favorisées mais malheureusement pas encore des pays plus pauvres. Cependant, les infections gastro-intestinales restent très fréquentes chez nous et sont souvent transmises par des aliments contaminés par des germes portés par les animaux producteurs de denrées alimentaires. Des stratégies de préventions de plus en plus sophistiquées sont mises en œuvre pour lutter contre elles; cela va de la vaccination des animaux ou des consommateurs à la mise en place de nouvelles technologies de traitement de nos aliments en passant par le développement de techniques innovantes pour la conservation de ceux-ci. Pour certains agents biologiques, les progrès sont spectaculaires pour d'autres c'est beaucoup plus difficile. La course en avant contre les micro-organismes a ses limites. Si nous voulons préserver notre alimentation variée, naturelle et riche en nutriments et en vitamines, nous ne pourrons détruire tous les germes dangereux, notamment dans les aliments crus. Il est temps d'envisager des alternatives. L'une des plus prometteuse est de lutter contre le mal par le mal, à savoir favoriser dans nos aliments des micro-organismes qui vont lutter contre ceux qui peuvent nous rendre malade mais aussi contre ceux qui vont dégrader la qualité de nos aliments et en provoquer le gaspillage. Le problème est que, pour mettre en œuvre cette stratégie du futur, il faut pouvoir avoir une vue globale de tous les organismes vivants qui, par milliards, occupent notre assiette. Jusque très récemment c'était techniquement impossible et donc très risqué. Les technologies basées sur l'étude d'un élément commun à tous les êtres vivants, à savoir leur patrimoine génétique, ouvre des perspectives extraordinaire pour mieux comprendre et essayer de maîtriser l'écologie de nos aliments et leur devenir dans notre tube digestif. Actuellement, en deux ou trois jours, on peut obtenir une liste presque exhaustive des centaines de membres différents d'un écosystème et on commence à associer certains avec le maintien d'une bonne santé. Il reste à les favoriser, notamment via l'ingestion de prébiotiques, nutriments spécifiques, ou même de probiotiques, micro-organismes sélectionnés, via des compléments alimentaires ou, mieux, d'aliments complets, alliant nutrition équilibrée et symbiotiques, combinaison des deux premiers cités. La boucle est ainsi bouclée. Le but est de montrer, via cet exposé, que le futur n'est pas à l'ingestion de conserves stériles additionnées d'additifs et de compléments divers en vue de prévenir les toxi-infections d'origine alimentaires mais à une alimentation riche et variée dont la flore est maîtrisée pour garantir la qualité des aliments et la santé de leurs consommateur, tout en ne négligeant pas l'hygiène qui restera toujours la base de la santé publique. [less ▲]

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See detailASSOCIATION OF CLASSICAL MICROBIOLOGY AND TARGETED METAGENOMIC ANALYSIS TO EVALUATE THE PRESENCE OF CLOSTRIDIUM DIFFICILE IN A BELGIAN NURSING HOME
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Korsak Koulagenko, Nicolas ULg et al

Conference (2013, October 22)

Increasing age, several co-morbidities, environmental contamination, antibiotic exposure and other intestinal perturbations appear to be the greatest risk factors for C. difficile infection (CDI ... [more ▼]

Increasing age, several co-morbidities, environmental contamination, antibiotic exposure and other intestinal perturbations appear to be the greatest risk factors for C. difficile infection (CDI). Therefore, elderly care home residents are considered particularly vulnerable to CDI. The main objective of this study was to evaluate and follow the prevalence of C. difficile in a Belgian nursing home. During a 4-month period, stool samples from a group of 23 elderly care home residents were collected weekly. A C. difficile microbiological detection scheme was performed along with an overall microbial biodiversity study of the faeces content by Targeted Metagenomic analysis. Surfaces and diary meals were also sampled in order to determinate the possible role of environmental and food contamination in the acquisition of CDI. Culture of samples was performed in a selective medium cycloserine cefoxitin fructose cholate. An identification of the isolated colonies was done by PCR detection of tpi, tcdA, tcdB and cdtA genes. Toxic activity was confirmed by a cytotoxic immunoassay. Further characterization was performed by PCR ribotyping. The Metagenomic analysis was targeted on the v1-v3 hyper-variable region of 16S rDNA. The taxonomical assignment of the populations was performed with MOTHUR and Blast algorithms. C. difficile was not detected in any of the tested meals or surfaces samples. For the stools samples, 6 of the 23 controlled residents were identified as C. difficile carriers. The isolates belonged to 4 different PCR ribotypes, including types 020 and 027. This unique association of classical microbiology protocol with pyrosequencing allowed to follow C. difficile in patients and to identify several other bacterial populations whose abundance is correlated with C. difficile. [less ▲]

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See detailBacterial diversity and its evolution during storage of fresh beef from different origins under different atmosphere and temperature conditions
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Taminiau, Bernard ULg et al

Poster (2013, October 11)

The purpose of this study was to evaluate the bacterial diversity and its evolution during storage of fresh beef, depending on its origin, packaging and storage temperature. Two batches of three vacuum ... [more ▼]

The purpose of this study was to evaluate the bacterial diversity and its evolution during storage of fresh beef, depending on its origin, packaging and storage temperature. Two batches of three vacuum packed striploins from United Kingdom and Belgium were obtained from a food wholesaler located in the Walloon Region. Fifteen days after slaughter, the striploins were sliced and individually kept under vacuum for 30 days: i) at −1 °C; ii) at +4 °C and iii) at −1 °C for 15 days and then at +4 °C for 15 days. The bacterial diversity was evaluated by metagenomic approach 15, 30 and 45 days after slaughter. Furthermore, each 15 days part of the vacuum packed striploin slices were repacked under modified atmosphere (70 % O2/30 % CO2), stored at +4 °C for 2 days and at +8 °C for 5 days, and then analyzed. Metagenomic analysis revealed a selection of the initial flora depending on atmosphere and temperature conditions. The development of Lactobacillus algidus was favored in samples preserved under vacuum at −1 °C, while a predominance of Lactococcus piscium was observed for samples stored at +4 °C. Moreover, storage under modified atmosphere favored the development of Leuconostoc gasicomitatum. These microorganisms have already been isolated from beef, but no study has evaluated their role in food conservation. The next step of this study will be to isolate and characterize strains of Lactobacillus algidus from meat and to assess their bioprotective potential. [less ▲]

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See detailGenetic and evolutionary perspectives on genogroup III, genotype 2 bovine noroviruses
Mauroy, Axel ULg; Scipioni, Alexandra; Mathijs, Elisabeth et al

in Archives of Virology (2013)

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See detailPresence of Clostridium difficile in pigs and cattle intestinal contents and carcass contamination at the slaughterhouse in Belgium.
Rodriguez Diaz, Cristina ULg; Avesani, V.; Van Broeck, J. et al

in International Journal of Food Microbiology (2013), 166(2), 256-262

The objective of this study was to evaluate the presence of Clostridium difficile in intestinal and carcass samples collected from pigs and cattle at a single slaughterhouse. C. difficile was isolated in ... [more ▼]

The objective of this study was to evaluate the presence of Clostridium difficile in intestinal and carcass samples collected from pigs and cattle at a single slaughterhouse. C. difficile was isolated in 1% and 9.9% of the pig and cattle intestinal contents and in 7.9% and 7% of cattle and pig carcass samples respectively. A total of 19 different PCR-ribotypes were identified, among them types 078 and 014. Seven of 19 ribotypes correlated with the PCR-ribotypes involved in human C. difficile infections in Belgium. This study confirms that animals are carriers of C. difficile at slaughter and ribotypes are identical than those in humans, and that carcass contamination occurs inside the slaughterhouse. [less ▲]

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See detailMicrobiological and Physico-Chemical Quality of Smoked Shrimp, An Expanding Food Condiment in Beninese Local Markets
Kpoclou, Euloge Y.; Anihouvi, Victor B.; Azokpota, Paulin et al

in Food and Public Health (2013), 3(6), 277-283

Entire Smoked Shrimp (ESS) and Smoked Shrimp Powder (SSP) are two food condiments widely used in Beninese local cooking practices. Twelve samples of each product collected from local markets were ... [more ▼]

Entire Smoked Shrimp (ESS) and Smoked Shrimp Powder (SSP) are two food condiments widely used in Beninese local cooking practices. Twelve samples of each product collected from local markets were evaluated for safety assessment using standard methods. Regarding the microbiological status of the samples, the Enterobacteriaceae were detected in 83% and 75% of ESS and SSP respectively, whereas 25% of samples of each product were found to contain E. coli. Pathogenic bacteria such as S. aureus and Salmonella were absent. Except 8% and 17% of SSP sample exceeding the maximal limit of 106 UFC/g for Aerobic Mesophilic Bacteria and 104 UFC/g Enterobacteriaceae respectively, all the other samples were within the acceptable limits. Water activity values were low, ranging between 0.54±0.01 for SSP and 0.61±0.01 for ESS, showing a potential microbial stability. Considering the chemical hazards, 15 EU priority polycyclic aromatic hydrocarbon (PAHs) were detected in the samples examined with median Benzo(a) pyrene and PAH4 contents (91 μg kg-1 and 490 μg kg-1respectively) exceeding the European maximal limit (5.0 μg kg-1 and 30 μg kg-1). This study showed that smoked shrimps may be generally safe from a microbiological point of view, but they constitute a large source of exposure to possible carcinogenic PAHs. [less ▲]

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See detailAntimicrobial Resistance in the food chain: a review
Verraes, Claire; Van Boxtael, Sigrid; Van Meervenne, Eva et al

in International Journal of Environmental Research and Public Health (2013), 10

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public ... [more ▼]

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance. [less ▲]

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See detailMicrobial characterization of probiotics-Advisory report of the Working Group "8651 Probiotics" of the Belgian Superior Health Council (SHC).
Huys, Geert; Botteldoorn, Nadine; Delvigne, Frank ULg et al

in Molecular Nutrition & Food Research (2013)

When ingested in sufficient numbers, probiotics are expected to confer one or more proven health benefits on the consumer. Theoretically, the effectiveness of a probiotic food product is the sum of its ... [more ▼]

When ingested in sufficient numbers, probiotics are expected to confer one or more proven health benefits on the consumer. Theoretically, the effectiveness of a probiotic food product is the sum of its microbial quality and its functional potential. Whereas the latter may vary much with the body (target) site, delivery mode, human target population, and health benefit envisaged microbial assessment of the probiotic product quality is more straightforward. The range of stakeholders that need to be informed on probiotic quality assessments is extremely broad, including academics, food and biotherapeutic industries, healthcare professionals, competent authorities, consumers, and professional press. In view of the rapidly expanding knowledge on this subject, the Belgian Superior Health Council installed Working Group "8651 Probiotics" to review the state of knowledge regarding the methodologies that make it possible to characterize strains and products with purported probiotic activity. This advisory report covers three main steps in the microbial quality assessment process, i.e. (i) correct species identification and strain-specific typing of bacterial and yeast strains used in probiotic applications, (ii) safety assessment of probiotic strains used for human consumption, and (iii) quality of the final probiotic product in terms of its microbial composition, concentration, stability, authenticity, and labeling. [less ▲]

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See detailRaw or heated cow milk consumption: Review of risks and benefits
Claeys, W. L.; Cardoen, S.; Daube, Georges ULg et al

in Food Control (2013), 31(1), 251-262

In the context of the prevailing trend toward more natural products, there seems to be an increasing preference for raw milk consumption as raw milk is associated with several perceived health benefits ... [more ▼]

In the context of the prevailing trend toward more natural products, there seems to be an increasing preference for raw milk consumption as raw milk is associated with several perceived health benefits that are believed to be destroyed upon heating. However, many human pathogens can be isolated from raw cow milk. The prevalence of foodborne pathogens in raw cow milk varies, but their presence has been demonstrated in many surveys and foodborne infections have been repeatedly reported for Campylobacter, Salmonella spp. and human pathogenic verocytotoxin-producing Escherichia coli. In industrialized countries, milk-borne and milk product-borne outbreaks represent 2-6% of the bacterial foodborne outbreaks.The aim of this review is to present scientifically sound data regarding the risks and benefits related to the consumption of raw and heated cow milk. Both microbiological aspects (e.g., the prevalence of milk-borne pathogens, pathogen growth inhibition by antimicrobial systems and by lactic acid producing bacteria, probiotic bacteria, etc.) and nutritional or health aspects (nutritional value, immunity, allergies, lactose intolerance, diabetes, milk digestibility, etc.) are considered.As such, it is demonstrated that consumption of raw milk poses a realistic health threat due to a possible contamination with human pathogens. It is therefore strongly recommended that milk should be heated before consumption. With the exception of an altered organoleptic profile, heating (in particularly ultra high temperature and similar treatments) will not substantially change the nutritional value of raw milk or other benefits associated with raw milk consumption. © 2012 Elsevier Ltd. [less ▲]

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See detailClostridium difficile in young farm animals and slaughter animals in Belgium
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Vandebroek, Johan et al

in Anaerobe (2012), 18(6), 621-625

Faecal carriage of Clostridium difficile in healthy animals has been reported recently, especially in piglets and calves. However there is limited data about carriage in animals just prior to slaughter in ... [more ▼]

Faecal carriage of Clostridium difficile in healthy animals has been reported recently, especially in piglets and calves. However there is limited data about carriage in animals just prior to slaughter in Europe. The main objective of this study was to determine the presence of C. difficile in pigs and cattle at the slaughterhouse. C. difficile was isolated in 6.9% of the cattle at the slaughterhouse. None of the pig slaughter samples were positive for C. difficile after an enrichment time of 72 h. For complementary data, a short study was conducted in piglets and calves at farms. C. difficile was more prevalent in piglets (78.3%) than in calves (22.2%) on the farms. Regarding the piglet samples, 27.8% of the positive samples were detected without enrichment of stools. The PCR ribotype 078 was predominant in farm animals. Samples isolated from slaughter cattle presented the widest range in PCR-ribotype variety, and the most prevalent PCR ribotype was 118a UCL. The results of this study confirm that C. difficile is present in slaughter animals in Belgium with a large percentage of toxigenic strains also commonly found in humans. [less ▲]

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See detailLa diversité bactérienne et son évolution pendant la conservation de viandes bovines fraîches de différentes origines conditionnées sous vide
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Taminiau, Bernard ULg et al

Poster (2012, December)

Le but de cette étude à été d'évaluer la diversité bactérienne et son évolution pendant la conservation de viandes bovine fraîches sous vide, en fonction de leur origine et du respect ou non d’une ... [more ▼]

Le but de cette étude à été d'évaluer la diversité bactérienne et son évolution pendant la conservation de viandes bovine fraîches sous vide, en fonction de leur origine et du respect ou non d’une température proche du point de congélation. Les dénombrements réalisés ont mis en évidence que les viandes d’origines britannique et belge testées présentent un écosystème microbien différent. Les analyses par approche métagénomique permettront d’éclaircir ces différences, surtout en ce qui concerne la présence de bactéries pouvant jouer un rôle "bioprotecteur" permettant d’améliorer la conservabilité des viandes. [less ▲]

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See detailRetrospective Analysis of a Listeria monocytogenes Contamination Episode in Raw Milk Goat Cheese Using Quantitative Microbial Risk Assessment tools
Delhalle, Laurent ULg; Ellouze, Mariem; Yde, Marc et al

in Journal of Food Protection (2012), 75(12), 2122-2135

In 2005, the Belgian authorities reported a Listeria monocytogenes contamination episode in cheese made from raw goat's milk. The presence of an asymptomatic shedder goat in the herd caused this ... [more ▼]

In 2005, the Belgian authorities reported a Listeria monocytogenes contamination episode in cheese made from raw goat's milk. The presence of an asymptomatic shedder goat in the herd caused this contamination. On the basis of data collected at the time of the episode, a retrospective study was performed using an exposure assessment model covering the production chain from the milking of goats up to delivery of cheese to the market. Predictive microbiology models were used to simulate the growth of L. monocytogenes during the cheese process in relation with temperature, pH, and water activity. The model showed significant growth of L. monocytogenes during chilling and storage of the milk collected the day before the cheese production (median increase of 2.2 log CFU/ml) and during the addition of starter and rennet to milk (median increase of 1.2 log CFU/ml). The L. monocytogenes concentration in the fresh unripened cheese was estimated to be 3.8 log CFU/g (median). This result is consistent with the number of L. monocytogenes in the fresh cheese (3.6 log CFU/g) reported during the cheese contamination episode. A variance-based method sensitivity analysis identified the most important factors impacting the cheese contamination, and a scenario analysis then evaluated several options for risk mitigation. Thus, by using quantitative microbial risk assessment tools, this study provides reliable information to identify and control critical steps in a local production chain of cheese made from raw goat's milk. [less ▲]

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See detailValidation de la qualité de la viande hachée de porc par une approche métagénomique ciblée
Taminiau, Bernard ULg; Nezer, Carine; Adolphe, Ysabelle ULg et al

Conference (2012, November 13)

Food products represent great biotopes for bacteria. The optimization of foodstuffs conservation pass by a better understanding of those biotopes and their spoilage. The current techniques of new ... [more ▼]

Food products represent great biotopes for bacteria. The optimization of foodstuffs conservation pass by a better understanding of those biotopes and their spoilage. The current techniques of new generation sequencing give a new dimension to the microbial ecology, through the metagenomic analysis of individuals' large number, within a mixed microbial population. Our aim is to demonstrate that this methodology can be successfully applied to the validation of the quality of foodstuffs during storage. This study was carried out on pork minced meat with shelf-life tests in various conditions of preservation (temperature and packaging). The analysis was performed in parallel with standardized microbiological methods and with massive sequencing of two hypervariables regions of the rDNA 16S. The results show an excellent correlation between the two approaches and underline the tremendous utility of metagenomic analysis for in-depth characterization of the potential altering bacteria in fresh meat. [less ▲]

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See detailViandes bovines à longue durée de conservation conditionnées sous vide : isolement et caractérisation de souches de Carnobacterium
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Baptista Rodrigues, Ana Lucia ULg et al

Poster (2012, November 13)

The lactic acid bacteria Carnobacterium divergens and Carnobacterium maltaromaticum are often associated to meat and meat products and may be used as a protective culture, improving the microbial ... [more ▼]

The lactic acid bacteria Carnobacterium divergens and Carnobacterium maltaromaticum are often associated to meat and meat products and may be used as a protective culture, improving the microbial stability and the safety of these products. In this context, the aim of this study was to isolate and characterize Carnobacterium from long shelf-life vacuum-packed beef. LAB counts after culture at +22°C remained below 2.0 log UFC/cm², even at the end of shelf life. On the other hand, the ecosystem evaluation performed by metagenomics revealed the predominance of Carnobacterium and Lactobacillus on the samples. After spreading of a peptone water suspension obtained from the samples on PCA, pure isolates were collected and identified by API 50 CHL galleries. Seventy-eight % of isolates were C. maltaromaticum, 3 % C. divergens and 19 % could not be identified. The next step of this work will consist in performing a genotypic and functional characterization of these Carnobacterium isolates. [less ▲]

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