References of "Daube, Georges"
     in
Bookmark and Share    
See detailMetagenomic analysis of the bacterial flora linked to the Algerian traditional date product “Btana”
Abekhti, Abdelkader; Taminiau, Bernard ULg; Kihla, Mabrouk et al

Poster (2014, September 01)

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailPredictive microbiology combined with metagenomic analysis targeted on the 16S rDNA : A new approach for food quality
Delhalle, Laurent ULg; Ellouze, Mariem; Taminiau, Bernard ULg et al

Poster (2014, September 01)

The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods may not be relevant to understand the modifications of the microbial ecology in food products ... [more ▼]

The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods may not be relevant to understand the modifications of the microbial ecology in food products. Metagenomic analysis targeted on 16S ribosomal DNA can elucidate microbial community structures at a muche higher resolution than was previously possible. Combined with predictive microbiological models, a new approach was investigated to take into account bacterial populations dynamics in perishable foods under different environmental conditions. White pudding samples, a typical Belgian pork meat product, were packed under food wrap (atmospheric air condition). Durability studies were conducted at 4°C, 12°C and a dynamic temperature profile according to the NF V01-003 standards (4°C (1/3 of the shelf life) - 8°C (2/3 of the shelf life)) during 15 days. The effect of organic acids was also investigated using a lactic acid (1.8% w/w) treatment. At each day of the trials, classical microbiological (total flora) and 16S rDNA metagenomic analysis were carried out on all these samples. For the metagenomic analysis, a sequencing library was generated, targeting the V1-V3 region of the 16S rDNA. The two major bacterial populations were thus identified (Psychrobacter sp and Brochotrix thermosphacta) and predictive microbiology models used to assess the growth parameters. Cardinal parameters for temperature were collected on the two main bacterial species. The model was validated using the data obtained at a dynamic temperature profile. The results of the simulations for Psychrobacter sp and Brochotrix thermosphacta show a good compliance between predicted and observed data. Compared to culture based methods on selective media and previous independent culture techniques, metagenomic analysis combined with predictive microbiology gives more valuable information, and could be considered as a technological breakthrough to control the quality or for accurately determining shelf life. [less ▲]

Detailed reference viewed: 86 (11 ULg)
Full Text
See detailMicrobiological risks and benefits of the consumption of raw milk and the effect of heat treatment
Verraes, Claire; Cardoen, S.; Claeys, W. et al

Conference (2014, September 01)

Detailed reference viewed: 22 (1 ULg)
Full Text
See detailMetagenomic insights into the dynamics and functionality of food microbial communities
Champomier Vergès, Marie-Christine; Daube, Georges ULg

Conference (2014, September)

Detailed reference viewed: 8 (1 ULg)
Full Text
See detailModelling the development of potential spoilage and biopreservative microorganisms on precooked pasta in different conditions of temperature based on classical microbiology and 16S rDNA metagenomic
Gand, Mathieu ULg; Cargnel, Mickaël ULg; Kergourlay, Gilles ULg et al

Poster (2014, September)

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food ... [more ▼]

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food products, it is not always the case with the consumers. Indeed, a few persons reach the right temperature level required for a safe storage of foodstuffs in their refrigerator. Besides, the food can sometimes spend a few hours in ambient temperature between the buying in the supermarket and the storage in cold temperature. In this study, we propose to model the growth of microorganisms on precooked pasta, stored in different conditions of temperature that reflect the situations described above (constant 4°C, constant 8°C, constant 12°C, 1/3 4°C – 2/3 8°C, 1/3 4°C – breach during 4h at 20°C – 2/3 8°C and 1/3 8°C – breach during 4h at 20°C – 2/3 8°C. The product was surface inoculated with potential spoilage and biopreservative strains (Lactococcus piscium, Leuconostoc mesenteroides and Leuconostoc citreum). Analyses by classical microbiology and V1-V3 16S rDNA metagenomics were done each day until the out of date of the food matrix. The transition from 4 to 8°C and the breach at 20°C during 4h have clearly boosted the growth of the microorganisms. The metagenomic analysis was a powerful tool to follow separately each population in each condition of storage. The results of this communication show the importance of keeping the foodstuffs in 4°C or lower in the refrigerator with the goal to avoid the spoilage or the development of pathogens and the potential of metagenomics for selection of biopreservative strains. [less ▲]

Detailed reference viewed: 97 (8 ULg)
Full Text
Peer Reviewed
See detailMultilocus sequence typing analysis and antibiotic resistance of Clostridium difficile strains isolated from retail meat and humans in Belgium
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Avesani, Véronique et al

in Food Microbiology (2014), 42

Clostridium difficile has been isolated from food animals and meat, specially ground pork and ground beef. The recovered isolates were closely related to C. difficile human strains, indicating that ... [more ▼]

Clostridium difficile has been isolated from food animals and meat, specially ground pork and ground beef. The recovered isolates were closely related to C. difficile human strains, indicating that animals and food are possible transmission routes of human C. difficile infection. The main objective of this study was to characterize C. difficile isolates from retail meat and to compare with human isolates recovered from hospital patients in Belgium. Raw meat (beef and pork) was obtained from the retail trade. C. difficile was recovered from 2.3% of the beef samples and from 4.7% of the pork samples. A total of 4 different PCR-ribotypes were identified with a large percentage of types 078 and 014. Resistance to moxifloxacin and erythromycin was detected. The multi-locus sequence typing (MLST) analysis showed that meat and human isolates cluster in the same lineage. This study reveals the presence of toxigenic C. difficile in retail meat in Belgium with predominance PCR-ribotypes 078 and 014, which are among the four most prevalent ribotypes of C. difficile isolated from humans in Europe. [less ▲]

Detailed reference viewed: 74 (24 ULg)
Full Text
See detailModelling the development of potential spoilage and biopreservative microorganisms on white pudding in different conditions of temperature based on classical microbiology and 16S rDNA metagenomic
Gand, Mathieu ULg; Cauchie, Emilie ULg; Kergourlay, Gilles ULg et al

Poster (2014, September)

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food ... [more ▼]

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food products, it is not always the case with the consumers. Indeed, a few persons reach the right temperature level required for a safe storage of foodstuffs in their refrigerator. Besides, the food can sometimes spend a few hours in ambient temperature between the buying in the supermarket and the storage in cold temperature. In this study, we propose to model the growth of microorganisms on white pudding, stored in different conditions of temperature that reflect the situations described above (constant 4°C, constant 8°C, constant 12°C, 1/3 4°C – 2/3 8°C, 1/3 4°C – breach during 4h at 20°C – 2/3 4°C and 1/3 4°C – breach during 4h at 20°C – 2/3 8°C. The product was surface inoculated with potential spoilage and biopreservative strains (Raoultella terrigena, Serratia quinivorans, Carnobacterium maltaromaticum, Lactobacillus oligofermentans, Lactobacillus nenjiangensis, Lactobacillus fuchuensis, Leuconostoc mesenteroides, lactococcus lactis and Lactobacillus graminis). Analyses by classical microbiology and V1-V3 16S rDNA metagenomics were done each day until the out of date of the food matrix. The transition from 4 to 8°C and the breach at 20°C during 4h have clearly boosted the growth of the microorganisms. The metagenomic analysis was a powerful tool to follow separately each population in each condition of storage. The results of this communication show the importance of keeping the foodstuffs in 4°C or lower in the refrigerator with the goal to avoid the spoilage or the development of pathogens and the potential of metagenomics for selection of biopreservative strains. [less ▲]

Detailed reference viewed: 225 (11 ULg)
Full Text
See detailCarnobacterium maltaromaticum isolated from vacuum-packed beef with long shelf life: morphological and functional characterization
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Ndedi Ekolo, François et al

Poster (2014, September)

This study was conducted as part of a research project on meat conservability, in particular vacuum packaged beef displaying very long shelf lives at a temperature close to the freezing point, and its ... [more ▼]

This study was conducted as part of a research project on meat conservability, in particular vacuum packaged beef displaying very long shelf lives at a temperature close to the freezing point, and its objective was to perform a morphological and functional characterization of C. maltaromaticum with potential bioprotective effect isolated from vacuum packaged long shelf life beef. The isolated C. maltaromaticum strain presented similar morphological, biochemical and enzymatic profiles as those of two reference strains (LMG 11393 and LMG 22902). Among the studied conditions, a temperature of +12 °C and an atmosphere poor in oxygen (100 % N2) were the optimal conditions for the growth of C. maltaromaticum. Nevertheless, growth on lower temperatures is also possible. After inoculation of beef samples with C. maltaromaticum and 7 days of storage under vacuum at −1 °C, no effect was observed on the total viable count and on the count of lactic acid bacteria. A reduction of Pseudomonas sp. and Brochothrix thermosphacta was observed during the first week of storage under vacuum conditions. After 7 days of subsequent storage of the same samples under modified atmosphere at +4 °C, the inoculant favored the growth of B. thermosphacta and inhibited the growth of Enterobacteriaceae under 100 % N2. No effect of the inoculant was observed when an atmosphere rich in oxygen was applied. The evaluation of the influence of different atmospheres showed that the growth of C. maltaromaticum was slower in an atmosphere containing O2 and CO2. Long-term storage under vacuum at low temperatures are therefore suitable for the growth of this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat stored under N2. The functional characterization of this strain will be further pursued by genotypic characterization. Special attention will be taken to study its bioprotective properties. [less ▲]

Detailed reference viewed: 108 (11 ULg)
Full Text
Peer Reviewed
See detailCarriage and acquisition rates of Clostridium difficile in hospitalized horses, including molecular characterization, multilocus sequence typing and antimicrobial susceptibility of bacterial isolates
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Brévers, Bastien et al

in Veterinary Microbiology (2014), 172

lostridium difficile has been identified as a significant agent of diarrhoea and enterocolitis in both foals and adult horses. Hospitalization, antibiotic therapy or changes in diet may contribute to the ... [more ▼]

lostridium difficile has been identified as a significant agent of diarrhoea and enterocolitis in both foals and adult horses. Hospitalization, antibiotic therapy or changes in diet may contribute to the development of C. difficile infection. Horses admitted to a care unit are therefore at greater risk of being colonized. The aim of this study was to investigate the carriage of C. difficile in hospitalized horses and the possible influence of some risk factors in colonization. During a seven-month period, faecal samples and data relating the clinical history of horses admitted to a veterinary teaching hospital were collected. C. difficile isolates were characterized through toxin profiles, cytotoxicity activity, PCR-ribotyping, antimicrobial resistance and multilocus sequence typing (MLST). Ten isolates were obtained with a total of seven different PCR-ribotypes, including PCR-ribotype 014. Five of them were identified as toxinogenic. A high resistance to gentamicin, clindamycin and ceftiofur was found. MLST revealed four different sequencing types (ST), which included ST11, ST26, ST2 and ST15, and phylogenetic analysis showed that most of the isolates clustered in the same lineage. Clinical history suggests that horses frequently harbour toxigenic and non-toxigenic C. difficile and that in most cases they are colonized regardless of the reason for hospitalization; the development of diarrhoea is more unusual. [less ▲]

Detailed reference viewed: 36 (8 ULg)
Full Text
Peer Reviewed
See detailAntimicrobial and molecular analysis of Salmonella serovar Livingstone strains isolated from humans in Tunisia and Belgium
Guedda, Intissar; Taminiau, Bernard ULg; Ferjani, Asma et al

in Journal of Infection in Developing Countries [=JIDC] (2014), 8

Introduction: Salmonella Livingstone is one of the most common serotypes responsible for nosocomial outbreaks in Tunisia. In this study, 42 isolates of Salmonella Livingstone were analyzed. Most of these ... [more ▼]

Introduction: Salmonella Livingstone is one of the most common serotypes responsible for nosocomial outbreaks in Tunisia. In this study, 42 isolates of Salmonella Livingstone were analyzed. Most of these were isolated from humans (31 strains from Tunisia and 9 strains from Belgium) and 2 isolates came from food products (beef and pork). Methodology: All strains were characterized by antibiogram, multilocus sequence typing (MLST), and virulotyping. This last technique was carried out by simple PCR of five chromosomal genes (agfA, hin/H2, iroB, phoP/Q, and slyA) and two plasmid genes (spvA and spvC). Results: All Tunisian strains were resistant to amoxicillin, amoxicillin-clavulanic acid, ticarcillin, cefalotin, gentamicin, and kanamycin. They were also resistant to third-generation cephalosporin antibiotics (cefotaxim and ceftazidim). Belgian isolates were susceptible to all antibiotics tested. Further to MLST analyses, Tunisian strains belonged to the same sequence type, ST543. For Belgian isolates, eight strains had a ST543 profile, two strains had a ST638 profile, and one strain had a ST457 profile. Analyses of the virulence gene contents showed that strains isolated in different years and from different origins had the same virulence profile. These carried all five chromosomal genes and lacked plasmid-located virulence genes spvA and spvC. Conclusions: A combination of different typing methods showed that the majority of Belgian strains and all Tunisian strains were closely related; they belonged to the same sequence type (ST543) and had the same virulence profile, but different antibiotic resistance profiles depended on the country of origin. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Full Text
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 et al

Poster (2014, August)

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from vacuum packaged long ... [more ▼]

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from 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. The isolated C. maltaromaticum strain presented similar morphological, biochemical and enzymatic profiles as those of two reference strains (LMG 11393 and LMG 22902). The growth of C. maltaromaticum was slower in an atmosphere containing O2 and CO2. Vacuum packing is therefore suitable for this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat stored under N2. The functional characterization of this isolate will be further pursued by a genotypic characterization to better understand its potential bioprotective effect. [less ▲]

Detailed reference viewed: 67 (15 ULg)
Peer Reviewed
See detailHigh throughput sequencing analysis reveals genetic variability and selection pressure in different murine norovirus genomic regions during in vitro replication
Mauroy, Axel ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Poster (2014, July)

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most ... [more ▼]

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most important etiological cause of both epidemic and sporadic gastroenteritis cases worldwide. Four open reading frames are described into its genome: ORF1 codes the non-structural (NS) proteins, including the viral RNA dependent RNA polymerase (RdRp); ORF2 codes the single capsid protein (VP1), wherein two domains are present: a relatively conserved domain (“shell”) and a more variable domain (“protruding”); ORF3 codes a minor structural protein; and ORF4, currently only found in viruses genetically related to MuNoV codes a virulence factor. In this study, we demonstrated by high throughput sequencing that, during serial passages of MuNoV in cell culture, the substitution rates, estimated by Bayesian inferences, did not significantly differ across the five targeted genomic regions except one. These rates were similar in four genomic regions encompassing partial non-structural 1-2 protein (NS1-2)-, NS5-, NS6-, NS7 (RdRp)- and VP1-coding sequences (coding the conserved part of the protein also including the ORF4 region). In the partial minor structural protein-coding region, this substitution rate was however estimated to be at least one log higher when expressed as substitution/site/day. The precise localisation of the detected nucleotide point mutations (substitution, deletion and insertion) were reported as well as the quantitative increase or decrease of the sequences harbouring them along ten cell culture passages. The non-silent amino acid mutations were also depicted in 3D models for four out of the five studied regions. These results have important implications for different norovirus research fields, especially in terms of diagnosis, classification methodology and genetic evolution. [less ▲]

Detailed reference viewed: 50 (2 ULg)
See detailXylo-oligosaccharides improve broiler performance by stimulating butyrate production by Clostridium cluster XIVa strains
De Maesschalck, C.; Nezer, Carine; Taminiau, Bernard ULg et al

Conference (2014, June 16)

Detailed reference viewed: 15 (1 ULg)
Full Text
See detailComparison and molecular characterization of animal and human Clostridium difficile strains
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Korsak Koulagenko, Nicolas ULg et al

Poster (2014, May 07)

The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing analysis ... [more ▼]

The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing analysis (MLST) was performed in order to study clonal relationships of the isolates. [less ▲]

Detailed reference viewed: 54 (9 ULg)
Full Text
Peer Reviewed
See detailStudy of the microbial flora of steak tartare by metagenomic approach
Korsak Koulagenko, Nicolas ULg; Delhalle, Laurent ULg; Nezer, Carine et al

Poster (2014, May 06)

Detailed reference viewed: 64 (8 ULg)
Peer Reviewed
See detailL'analyse par séquençage à haut débit révèle la variabilité génétique et la pression de sélection dans différentes régions génomiques du norovirus murin durant sa réplication in vitro
Mauroy, Axel ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Conference (2014, March)

Le norovirus murin (MuNoV), un virus à ARN de polarité positive appartenant à la famille des Caliciviridae, est considéré comme un modèle adéquat pour les infections humaines à norovirus, une des causes ... [more ▼]

Le norovirus murin (MuNoV), un virus à ARN de polarité positive appartenant à la famille des Caliciviridae, est considéré comme un modèle adéquat pour les infections humaines à norovirus, une des causes étiologiques les plus importantes dans les cas de gastroentérite épidémique ou sporadique dans le monde entier. Quatre cadres de lecture ouverts (ORF) sont décrits au sein de son génome : l’ORF1 code les protéine non structurales (NS), dont l’ARN polymérase ARN dépendante virale (RdRp) ; l’ORF2 code l’unique protéine de capside (VP1), dans laquelle sont décrites deux régions : une relativement conservée (domaine « shell ») et une autre beaucoup plus variable (domaine « protruding ») ; l’ORF3 code une protéine structurale mineure ; et l’ORF4, actuellement uniquement décrit chez les virus génétiquement apparentés au MuNoV, code un facteur de virulence. Dans cette étude, nous démontrons par séquençage à haut débit que, durant des passages successifs du MuNoV en culture cellulaire, les taux de substitution, estimés par inférences Bayésiennes, n’ont pas significativement différé au travers des cinq régions génomiques ciblées à l’exception d’une région bien précise. Ces taux étaient similaires pour quatre régions englobant des séquences partielles codant les protéines non structurales NS1-2, NS5, NS6 et NS7 (RdRp) et VP1 dans sa région conservée (incluant également l’ORF4). Dans la région codant partiellement la protéine structurale mineure, ce taux de substitution, exprimé en substitution/site/jour, a été cependant estimé être plus élevée d’au moins une unité logarithmique. La localisation précise des mutations ponctuelles détectées (substitution, délétion et insertion) est rapportée ainsi que l’augmentation ou la diminution quantitative du nombre des séquences qui les présentaient au cours de dix passages successifs en culture cellulaire. Les localisations des mutations non silencieuses ont aussi été représentées dans une modélisation tridimensionnelle de quatre des cinq régions étudiées. Ces résultats ont d’importantes implications pour différents champs de recherche sur les norovirus, spécialement en termes de diagnostic, de méthodologie de classification et d’évolution génétique. [less ▲]

Detailed reference viewed: 70 (3 ULg)
Full Text
Peer Reviewed
See detailProduction and microbiological evaluation of three types of "Dèguè", a local fermented drink made from milk in Benin
Tchekessi, Célestin; Bokossa, Auréole; Agbangla, Clément et al

in International Journal of Multidisciplinary and Current Research (2014), 2

This study consists to finalize some technologies for the production of a fermented drink called dèguè. This drink is widely consumed in Benin and other countries in sub-Saharan Africa. Following three ... [more ▼]

This study consists to finalize some technologies for the production of a fermented drink called dèguè. This drink is widely consumed in Benin and other countries in sub-Saharan Africa. Following three different technologies, we had produced three (03) types of dèguè respectively with maize flour, sorghum and millet. These types have been analyzed and their microbiological characteristics were evaluated. The microbiological analysis results obtained from the experiments have shown that lactic acid bacteria, yeasts and molds were the dominant microflora of dèguè and varied respectively 7.22log10UFC/g to 7.55log10UFC/g for lactic acid bacteria and 7.78log10UFC/g to 8.44log10UFC/g for yeasts and molds. Moreover, the statistical analysis of these results showed that there was no significant difference at 5% (p <0.05) between the three types of dèguè. The values of lactic acid bacteria obtained were consistent with the standard (≥ 107/g) attached to the yoghurt. No type contained neither total coliforms nor thermotolerant coliforms. The products (dèguès) were also free of pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus and Salmonella. [less ▲]

Detailed reference viewed: 89 (12 ULg)
Full Text
Peer Reviewed
See detailIsolation and Quantification of Lactic Acid Bacteria from Traditional Fermented Products in Benin
Tchekessi, C.K.C.; Bokossa, I.Y; Azokpota, P. et al

in International Journal of Current Microbiology and Applied Sciences (2014), 3(11), 1-8

In Africa, fermented food products are particularly used as weaning foods for young children, pregnant women and the seniors. In Benin, most of these cereals-based foods are manufactured and sold around ... [more ▼]

In Africa, fermented food products are particularly used as weaning foods for young children, pregnant women and the seniors. In Benin, most of these cereals-based foods are manufactured and sold around the streets. These are ablo, dèguè, akpan, abotin, gowé etc ... This study focused on the isolation and enumeration of bacteria and yeast from twenty six (26) samples of traditional African fermented foods. Decimal dilution method allowed us to isolate a total of 42 different strains of microorganisms among which we counted 30 lactic acid bacteria. They confirmed their biological potential by expanding in selective medium MRS. When they were then subjected to screening, the medium of MRS-broth-starch agar, and eight (08) of the isolated strains tested showed their characters of amylolytic strains. The eight strains isolated were tested and finally cultivated at temperatures and pH ranging respectively from 30°C to 60°C and 3.0 to 6.5. These eight (08) amylolytic lactic acid bacteria (ALAB) synthesized enzyme amylase both inside and outside the bacterial cell with a very interesting activity value. The temperature limit between 40 and 45°C is best for the bacteria 26.2, B16 and B18 while the optimum pH for amylase synthesis is between 4.0 and 4.5 for the same microorganisms that have given the largest values of enzyme activity. The best strains 26.2, B16 and B18 secrete more enzymes in extracellular medium than intracellular. [less ▲]

Detailed reference viewed: 116 (4 ULg)
Full Text
Peer Reviewed
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, Éléonore; Bokossa, Innocent et al

in Journal of Essential Oil-Bearing Plants [=JEOBP] (2014)

BACKGROUND: The aim of present the study was to investigate the chemical composition and the antimicrobial activity of essential oils of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as ... [more ▼]

BACKGROUND: The aim of present the study was to investigate the chemical composition and the antimicrobial activity of essential oils of Ocimum basilicum, Ocimum canum and Ocimum gratissimum from Benin as affected by harvesting time. The chemical composition of hydrodistillated essential oils were analyzed by GC-FID (gas chromatography – flame ionization detector) and GC-MS (gas chromatography-mass spectrometry). Disc diffusion and broth microdilution assays were used to evaluate the antibacterial activity of essential oils against two foodborne pathogens. RESULTS: 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. The tested oils and their components exhibited notable antimicrobial activities against Listeria monocytogenes and Salmonella 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). CONCLUSION: The daytime of harvest can influence the composition of oils and their activities on bacteria. [less ▲]

Detailed reference viewed: 13 (1 ULg)