scholarly journals Antilisterial Effect and Influence on Listeria monocytogenes Gene Expression of Enterocin or Enterococcus faecalis in Sliced Dry-Cured Ham Stored at 7°C

2019 ◽  
Vol 82 (9) ◽  
pp. 1598-1606 ◽  
Author(s):  
RAQUEL MONTIEL ◽  
ANA QUESILLE-VILLALOBOS ◽  
VALENTINA ALESSANDRIA ◽  
MARGARITA MEDINA ◽  
LUCA SIMONE COCOLIN ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecalis ◽  
Storage Period ◽  
Pronounced Effect ◽  
Down Regulation ◽  
Common Trend ◽  
Dry Cured Ham

ABSTRACT In this study, we focused on the effect of an enterocin or an Enterococcus faecalis strain added onto sliced dry-cured ham that was artificially inoculated with Listeria monocytogenes and stored at 7°C. The population of L. monocytogenes and the expression of five genes were monitored throughout the storage period. A persistent and a nonpersistent strain were tested, and both were influenced by the presence of the enterocin; both populations were reduced by more than 2 Log CFU/g after 14 days compared with the control, noninoculated ham. The presence of E. faecalis, a bacteriocin-producing lactic acid bacterium, had a less pronounced effect on the viable counts for both strains. Concerning gene expression, a common trend observed for both strains in the presence of enterocin was the down-regulation of genes tested after 30 min of storage at 7°C. For the remainder of the storage period, the expression fluctuated but was mostly reduced. Similarly, the presence of E. faecalis led to an overall down-regulation of genes. The effect on gene expression of both enterocin and E. faecalis was more pronounced on the nonpersistent L. monocytogenes strain. Although the potential of a bacteriocin and a bacteriocin-producing microorganism to control L. monocytogenes was confirmed, this study highlights that gene expression may be influenced and needs to be evaluated when considering such biopreservation interventions.

scholarly journals Draft Genome Sequence of Enterococcus faecalis DD14, a Bacteriocinogenic Lactic Acid Bacterium with Anti-Clostridium Activity

2017 ◽  
Vol 5 (30) ◽  
Author(s):  
Yanath Belguesmia ◽  
Valérie Leclère ◽  
Matthieu Duban ◽  
Eric Auclair ◽  
Djamel Drider
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecalis ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Coding Sequences ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Healthy Newborn

ABSTRACT We report the draft genome sequence of Enterococcus faecalis DD14, a strain isolated from meconium of a healthy newborn at Roubaix Hospital (France). The strain displayed antagonism against a set of Gram-positive bacteria through concomitant production of lactic acid and bacteriocin. The genome has a size of 2,893,365 bp and a 37.3% G+C ratio and is predicted to contain at least 2,755 coding sequences and 62 RNAs.

Properties of Labneh-Like Product Manufactured Using Enterococcus Starter Cultures as Novel Dairy Fermentation Bacteria

1988 ◽  
Vol 51 (5) ◽  
pp. 386-390 ◽  
Author(s):  
Y. A. EL-SAMRAGY ◽  
E. O. FAYED ◽  
A. A. ALY ◽  
A. E. A. HAGRASS
Keyword(s):  
Lactic Acid ◽  
Enterococcus Faecalis ◽  
Starter Culture ◽  
Storage Period ◽  
Titratable Acidity ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Lactobacillus Bulgaricus ◽  
Soluble Nitrogen ◽  
Acid Fermentation

The traditional yogurt starter, i.e. Staphylococcus thermophilus and Lactobacillus bulgaricus, has always been used to bring about the lactic acid fermentation during manufacture of concentrated yogurt known in Egypt as “Labneh”. Different combinations of some strains of Enterococcus faecalis, isolated from Laban Rayeb (a type of fermented milk), in combination with a certain strain of Lactobacillus bulgaricus were used to produce a Labneh-like product. Chemical, microbiological and organoleptic properties of the Labneh-like product were assessed and compared to the characteristics of Labneh processed traditionally by two different dairy plants in Egypt. All treatments showed similar changes during storage at 5 ± 1°C for 28 d. Total solids, fat, titratable acidity and pH values coincided with those of Labneh. Some components increased until the seventh day, i.e. acetaldehyde and diacetyl, while other features, such as the ratio of soluble nitrogen/total nitrogen and tyrosine, increased until the fourteenth day of storage. Thereafter, no marked variations occurred. However, a decrease in tryptophan content of all products occurred during the storage period. Total viable count and count of lactic acid bacteria of Labneh-like product as well as Labneh increased until the end of the second week of storage and then decreased. Coliforms, yeasts and molds and psychrotrophic bacteria were detected in some fresh and stored samples. The starter culture which consisted of 1.5% Enterococcus faecalis 19 and 1.5% Enterococcus faecalis 22 was used successfully to manufacture a Labneh-like product with high acceptability when fresh or refrigerated at 5 ± 1°C.

scholarly journals The Antisense RNA Approach: a New Application forIn VivoInvestigation of the Stress Response of Oenococcus oeni, a Wine-Associated Lactic Acid Bacterium

2015 ◽  
Vol 82 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Maud Darsonval ◽  
Tarek Msadek ◽  
Hervé Alexandre ◽  
Cosette Grandvalet
Keyword(s):  
Gene Expression ◽  
Lactic Acid ◽  
Stress Response ◽  
Lactic Acid Bacterium ◽  
Antisense Rna ◽  
Expression Vector ◽  
Stress Proteins ◽  
Oenococcus Oeni ◽  
Content Type

ABSTRACTOenococcus oeniis a wine-associated lactic acid bacterium mostly responsible for malolactic fermentation in wine. In wine,O. oenigrows in an environment hostile to bacterial growth (low pH, low temperature, and ethanol) that induces stress response mechanisms. To survive,O. oeniis known to set up transitional stress response mechanisms through the synthesis of heat stress proteins (HSPs) encoded by thehspgenes, notably a unique small HSP named Lo18. Despite the availability of the genome sequence, characterization ofO. oenigenes is limited, and little is known about thein vivorole of Lo18. Due to the lack of genetic tools forO. oeni, an efficient expression vector inO. oeniis still lacking, and deletion or inactivation of thehsp18gene is not presently practicable. As an alternative approach, with the goal of understanding the biological function of theO. oenihsp18genein vivo, we have developed an expression vector to produce antisense RNA targeting ofhsp18mRNA. Recombinant strains were exposed to multiple stresses inducinghsp18gene expression: heat shock and acid shock. We showed that antisense attenuation ofhsp18affectsO. oenisurvival under stress conditions. These results confirm the involvement of Lo18 in heat and acid tolerance ofO. oeni. Results of anisotropy experiments also confirm a membrane-protective role for Lo18, as previous observations had already suggested. This study describes a new, efficient tool to demonstrate the use of antisense technology for modulating gene expression inO. oeni.

Inhibition of Salmonella Typhimurium and Listeria monocytogenes in Mung Bean Sprouts by Chemical Treatment

2002 ◽  
Vol 65 (7) ◽  
pp. 1088-1092 ◽  
Author(s):  
SUN-YOUNG LEE ◽  
KYUNG-MI YUN ◽  
J. FELLMAN ◽  
DONG-HYUN KANG
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Mung Bean ◽  
Storage Period ◽  
Log Reduction ◽  
Mung Bean Sprouts ◽  
Chlorous Acid ◽  
Bean Sprouts

This study was undertaken to compare the efficacies of chlorous acid (268 ppm), sodium hypochlorite (200 ppm), and lactic acid (2%) in eliminating total mesophilic microorganisms, Salmonella Typhimurium, and Listeria monocytogenes on commercial mung bean sprouts immediately after treatment and during posttreatment refrigerated storage. Treatment with sodium hypochlorite for 10 min did not reduce the total aerobic count. However, treatment with lactic acid and chlorous acid for 10 min initially reduced the total aerobic count by 0.6 and 0.8 log CFU/g, respectively, and maintained the same level or a lower level of the total aerobic count during the storage time. Treatment with chlorous acid reduced Salmonella Typhimurium from 5.0 log to undetectable levels (<0.48 log CFU/g), and the pathogen remained undetectable over a 9-day storage period. Treatment with lactic acid resulted in an initial 3-log reduction and further reduced the number of Salmonella Typhimurium cells to undetectable levels after 3 days. For L. monocytogenes, treatment with chlorous acid resulted in an initial 5-log reduction, and treatment with lactic acid resulted in a 2-log reduction at the beginning and undetectable levels after 9 days. When chemically injured cells were investigated by the selective overlay method, no statistical difference was observed (P < 0.05) between the number of injured cells recovered following treatment with chlorous acid and the number of bacteria counted on selective media, whereas sodium hypochlorite generated more injured cells than the other treatments did. These data suggest that treatment with chlorous acid may be useful in reducing total mesophilic microorganisms, Salmonella Typhimurium, and L. monocytogenes in commercial mung bean sprouts.

scholarly journals Bryndza cheese of Slovak origin as potential resources of probiotic bacteria

10.5219/1413 ◽  
2020 ◽  
Vol 14 ◽  
pp. 641-646
Author(s):  
Miroslava Kačániová ◽  
Petra Borotová ◽  
Margarita Terenjeva ◽  
Simona Kunová ◽  
Soňa Felsöciová ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Yersinia Enterocolitica ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Bryndza cheese includes several predominant lactic acid bacteria. The aim of our study was the antagonistic effect of lactic acid bacteria supernatant isolated from ewes´ cheese bryndza against ten Gram-positive and Gram-negative bacteria. Isolated strains of bacteria were obtained from bryndza which were produced in five different regions of Slovakia. Isolated strains of lactic acid bacteria were identified with mass spectrometry MALDI-TOF MS Biotyper. A total of one hundred and thirty lactic bacteria include Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Lactobacillus brevis, Lactobacillus harbinensis, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus paracasei ssp. paracasei, Lactobacillus paraplantarum, Lactobacillus suebicus, Lactococcus lactis ssp. lactis, Lactococcus lactis, and Pediococcus acidilactici were tested in this study against Gram-negative bacteria: Escherichia coli CCM 3988, Klebsiella pneumoniae CCM 2318, Salmonella enterica subsp. enterica CCM 3807, Shigella sonnei CCM 1373, Yersinia enterocolitica CCM 5671 and Gram-positive bacteria: Bacillus thuringiensis CCM 19, Enterococcus faecalis CCM 4224, Listeria monocytogenes CCM 4699, Staphylococcus aureus subsp. aureus CCM 2461, Streptococcus pneumonia CCM 4501 with agar diffusion method. Lactic acid bacteria showed activity 92% against Yersinia enterocolitica, 91% against Klebsiella pneumoniae, 88% against Escherichia coli, 84% against Listeria monocytogenes. The most effective bacteria against Gram-positive and Gram-negative bacteria tested was Lactobacillus paracasei ssp. paracasei.

scholarly journals Draft Genome Sequence of the Bacteriocinogenic Strain Enterococcus faecalis DBH18, Isolated from Mallard Ducks ( Anas platyrhynchos )

2016 ◽  
Vol 4 (4) ◽  
Author(s):  
Sara Arbulu ◽  
Juan J. Jimenez ◽  
Juan Borrero ◽  
Jorge Sánchez ◽  
Cyril Frantzen ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecalis ◽  
Genome Sequence ◽  
Dna Sequences ◽  
Anas Platyrhynchos ◽  
Draft Genome ◽  
Draft Genome Sequence

Here, we report the draft genome sequence of Enterococcus faecalis DBH18, a bacteriocinogenic lactic acid bacterium (LAB) isolated from mallard ducks ( Anas platyrhynchos ). The assembly contains 2,836,724 bp, with a G+C content of 37.6%. The genome is predicted to contain 2,654 coding DNA sequences (CDSs) and 50 RNAs.

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