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JPMA. the Journal of the Pakistan... May 2018Enterococci are known as opportunistic pathogens and today are accepted as leading cause of nosocomial infections. Various enterococcal species have been identified, but... (Review)
Review
Enterococci are known as opportunistic pathogens and today are accepted as leading cause of nosocomial infections. Various enterococcal species have been identified, but the major two which cause human diseases are enterococcus faecalis and enterococcus faecium. Most common and important infections caused by them are bacteraemia, endocarditis, urinary tract infections, surgical wound infections, intra-abdominal and intra-pelvic infections. Over the last two decades the emergence of vancomycin-resistant enterococci is alarming because of high mortality rate. Being resistant nosocomial infectious agents, vancomycin-resistant enterococci are a serious threat to current healthcare practices. Antibiotic resistance determinants VanA and VanB are globally reported in vancomycin-resistant enterococci clinical isolates. This paper covers a comprehensive overview of vancomycin-resistant enterococci infection epidemiology, virulence, drug resistance, its prevention and treatment.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Carbon-Oxygen Ligases; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Vancomycin; Vancomycin Resistance; Vancomycin-Resistant Enterococci
PubMed: 29885179
DOI: No ID Found -
Food Microbiology Aug 2021The accumulation of ethanol has a negative effect on the viability and fermentation performance of microorganisms during the production of fermented foods because of its... (Review)
Review
The accumulation of ethanol has a negative effect on the viability and fermentation performance of microorganisms during the production of fermented foods because of its toxicity. In this study, we investigated the effect of co-culture with Tetragenococcus halophilus on ethanol stress resistance of Zygosaccharomyces rouxii. The result showed that co-culture with T. halophilus promoted cell survival of Z. rouxii under ethanol stress, and the tolerance improved with increasing co-culture time when ethanol content was 8%. Physiological analysis showed that the co-cultured Z. rouxii cells maintained higher intracellular content of trehalose and amino acids including tyrosine, tryptophan, arginine and proline after 8% ethanol stress for 90 min. The membrane integrity analysis and biophysical analysis of the cell surface indicated that the presence of ethanol resulted in cell membrane damage and changes of Young's modulus value and roughness of cell surface. While the co-cultured Z. rouxii cells exhibited better membrane integrity, stiffer and smoother cell surface than single-cultured cells under ethanol stress. As for transcriptomic analyses, the genes involved in unsaturated fatty acid biosynthesis, trehalose biosynthesis, various types of N-glycan biosynthesis, inositol phosphate metabolism, MAPK signaling pathway and tight junction had higher expression in co-cultured Z. rouxii cells with down-regulation of majority of gene expression after stress. And these genes may function in the improvement of ethanol tolerance of Z. rouxii in co-culture.
Topics: Amino Acids; Bacterial Proteins; Coculture Techniques; Enterococcaceae; Ethanol; Fermentation; Fungal Proteins; Saccharomycetales; Surface Properties
PubMed: 33653523
DOI: 10.1016/j.fm.2021.103750 -
Food Research International (Ottawa,... Nov 2022Biofilms were found to promote the survival of Tetragenococcus halophilus, a functional halophilic lactic acid bacterium in the production of high-salt fermented foods... (Review)
Review
Biofilms were found to promote the survival of Tetragenococcus halophilus, a functional halophilic lactic acid bacterium in the production of high-salt fermented foods under various environmental stresses including ethanol stress. Here, a comprehensive exploration of the response of T.halophilus biofilms and planktonic cells to ethanol stress was performed. Biofilms showed an ability to reduce death and damage of cell membrane and wall under 12% ethanol stress The formation of biofilm changed the characteristic of Fourier transformed infrared spectroscopy (FT-IR). RNA-seq technology and iTRAQ technology revealed the differential expression of genes and proteins in biofilm and planktonic cells with or without ethanol treatment. The differentially expressed genes and proteins played positive roles in the biosynthesis of polysaccharides, proteins, and DNA, benefitting biofilm matrix production. The shelter provided by biofilms and the differential expression of genes and proteins involved in citrate formation, malate utilization, and the biosynthesis of tryptophan, fatty acid, lipoteichoic acid, and peptidoglycan might contribute to the stress tolerance of biofilm cells together. Results presented in this study may contribute to our understanding of biofilm formation by T. halophilus and the roles of bacterial biofilm in stress tolerance.
Topics: Biofilms; Citrates; Enterococcaceae; Ethanol; Fatty Acids; Lactic Acid; Malates; Peptidoglycan; Proteomics; Spectroscopy, Fourier Transform Infrared; Transcriptome; Tryptophan
PubMed: 36192889
DOI: 10.1016/j.foodres.2022.111817 -
Microbiology Spectrum Jul 2018Enterococci are natural inhabitants of the intestinal tract in humans and many animals, including food-producing and companion animals. They can easily contaminate the... (Review)
Review
Enterococci are natural inhabitants of the intestinal tract in humans and many animals, including food-producing and companion animals. They can easily contaminate the food and the environment, entering the food chain. Moreover, is an important opportunistic pathogen, especially the species and , causing a wide variety of infections. This microorganism not only contains intrinsic resistance mechanisms to several antimicrobial agents, but also has the capacity to acquire new mechanisms of antimicrobial resistance. In this review we analyze the diversity of enterococcal species and their distribution in the intestinal tract of animals. Moreover, resistance mechanisms for different classes of antimicrobials of clinical relevance are reviewed, as well as the epidemiology of multidrug-resistant enterococci of animal origin, with special attention given to beta-lactams, glycopeptides, and linezolid. The emergence of new antimicrobial resistance genes in enterococci of animal origin, such as and , is highlighted. The molecular epidemiology and the population structure of and isolates in farm and companion animals is presented. Moreover, the types of plasmids that carry the antimicrobial resistance genes in enterococci of animal origin are reviewed.
Topics: Animals; Anti-Infective Agents; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Farms; Food Microbiology; Gastrointestinal Tract; Gram-Positive Bacterial Infections; Humans; Molecular Epidemiology; Pets
PubMed: 30051804
DOI: 10.1128/microbiolspec.ARBA-0032-2018 -
Food Research International (Ottawa,... Jun 2019Soy sauce is an increasingly popular oriental fermented condiment produced through a two-step fermentation process called koji (solid-state fermentation) and moromi... (Review)
Review
Soy sauce is an increasingly popular oriental fermented condiment produced through a two-step fermentation process called koji (solid-state fermentation) and moromi (brine fermentation). Complex microbial interactions play an essential role in its flavor development during the fermentation. Tetragenococcus halophilus and Zygosaccharomyces rouxii are predominant among the microbes involved in the moromi stage. Despite their importance for producing a wide range of volatile compounds, antagonism can occur due to different growth condition requirements. Furthermore, microbial interactions in moromi fermentation are affected by current efforts to reduce salt in soy sauce, in order to tackle slow fermentation due to low metabolic activity of microbes and increased health risk related to high sodium intake. Attempts to enhance and accelerate flavor formation in the presence of high salt concentration include the inoculation with mixed starter cultures, genetic modification, cell, and enzyme immobilization. Although salt reduction can accelerate the microbial growth, the flavor quality of soy sauce is compromised. Several approaches have been applied to compensate such loss in quality, including the use of salt substitutes, combination of indigenous cultures, pretreatment of raw material and starter cultures encapsulation. This review discusses the role of microorganisms in soy sauce production in relation to flavor formation and changes in production practices.
Topics: Biodiversity; Cell Encapsulation; Enterococcaceae; Fermentation; Fermented Foods; Flavoring Agents; Immobilization; Microbiota; Odorants; Sodium Chloride; Sodium Chloride, Dietary; Soy Foods; Taste; Zygosaccharomyces
PubMed: 31000250
DOI: 10.1016/j.foodres.2019.03.010 -
BMC Microbiology Jun 2022Probiotic starters can improve the flavor profile, texture, and health-promoting properties of fermented foods. Tetragenococcus halophilus is a halophilic lactic acid...
BACKGROUND
Probiotic starters can improve the flavor profile, texture, and health-promoting properties of fermented foods. Tetragenococcus halophilus is a halophilic lactic acid bacterium that is a candidate starter for high-salt fermented foods. However, the species is known to produce biogenic amines, which are associated with neurotoxicity. Here, we report a probiotic starter strain of T. halophilus, EFEL7002, that is suitable for use in high-salt fermentation.
RESULTS
EFEL7002 was isolated from Korean meju (fermented soybean) and identified as T. halophilus, with 99.85% similarity. The strain is safe for use in food as it is a non-hemolytic and non-biogenic amine producer. EFEL7002 is tolerant to gastrointestinal conditions and can adhere to Caco-2 cells. This strain showed antioxidant, anti-inflammatory, and protective effects against the human gut epithelial barrier. EFEL7002 grew well in media containing 0-18% NaCl showing maximum cell densities in 6% or 12% NaCl.
CONCLUSIONS
T. halophilus EFEL7002 can be used as a health-promoting probiotic starter culture for various salty fermented foods.
Topics: Biogenic Amines; Caco-2 Cells; Enterococcaceae; Fermentation; Food Microbiology; Humans; Probiotics; Republic of Korea; Sodium Chloride; Glycine max
PubMed: 35668352
DOI: 10.1186/s12866-022-02561-7 -
Cells Jun 2022Ulcerative colitis (UC) is one of the major subtypes of inflammatory bowel disease with unknown etiology. Probiotics have recently been introduced as a treatment for UC....
Ulcerative colitis (UC) is one of the major subtypes of inflammatory bowel disease with unknown etiology. Probiotics have recently been introduced as a treatment for UC. () is a lactic acid-producing bacterium that survives in environments with high salt concentrations, though little is known about its immunomodulatory function as a probiotic. The purpose of this study is to determine whether exerts an anti-inflammatory effect on intestinal inflammation in mice. Colitis was induced in C57BL/6J mice by feeding 4% DSS in drinking water for 7 days. was orally administered with DSS. Anti-inflammatory functions were subsequently evaluated by flow cytometry, qRT-PCT, and ELISA. Gut microbial composition was analyzed by 16S rRNA metagenomic analysis. DSS-induced colitis mice treated with showed less weight loss and significantly suppressed colonic shortening compared to DSS-induced colitis mice. significantly reduced the frequency of the dendritic cell activation molecule CD83 in peripheral blood leukocytes and intestinal epithelial lymphocytes. Frequencies of CD8+NK1.1+ cells decreased in mice with colitis after treatment and IL-1β levels were also reduced. Alteration of gut microbiota was observed in mice with colitis after administration of . These results suggest is effective in alleviating DSS-induced colitis in mice by altering immune regulation and gut microbiome compositions.
Topics: Animals; Anti-Inflammatory Agents; Colitis; Colitis, Ulcerative; Dendritic Cells; Dextran Sulfate; Enterococcaceae; Gastrointestinal Microbiome; Inflammation; Mice; Mice, Inbred C57BL; RNA, Ribosomal, 16S
PubMed: 35741032
DOI: 10.3390/cells11121903 -
The Journal of General and Applied... Jan 2018
Comparative Study
Topics: Bacterial Proteins; DNA, Bacterial; Enterococcaceae; Genes, Bacterial; Genome, Bacterial; Genomics; Metabolic Networks and Pathways; Sequence Analysis, DNA; Soy Foods; Species Specificity
PubMed: 29046500
DOI: 10.2323/jgam.2017.02.003 -
Journal of Biochemistry Sep 2022The aspartate:alanine exchanger family of membrane transporters includes industrially important transporters such as succinate exporter and glutamate exporter. No...
The aspartate:alanine exchanger family of membrane transporters includes industrially important transporters such as succinate exporter and glutamate exporter. No high-resolution structure is available from this family so far, and the transport mechanism of these transporters also remains unclear. In the present study, we focus on the oligomeric status of the aspartate:alanine antiporter (AspT) of Tetragenococcus halophilus, which is the prototype of this family. To investigate the oligomeric structure of AspT, we established a system that produces high yields of highly purified AspT and determined the oligomeric structure of AspT by analysis with size exclusion chromatography coupled with multi-angle light scattering and blue native PAGE and by comparison of the wild-type AspT with a single-cysteine mutant that forms spontaneous inter-molecular thiol crosslinking. All the results consistently support the notion that AspT is a homodimer in solutions and in membranes.
Topics: Alanine; Antiporters; Aspartic Acid; Cysteine; Enterococcaceae; Glutamates; Membrane Transport Proteins; Succinates
PubMed: 35818339
DOI: 10.1093/jb/mvac057 -
Food Microbiology Sep 2019Biogenic amines (BAs) are frequently present in traditionally fermented salted foods. In this study, a Tetragenococcus halophilus strain (MJ4) with no BA-producing...
Biogenic amines (BAs) are frequently present in traditionally fermented salted foods. In this study, a Tetragenococcus halophilus strain (MJ4) with no BA-producing ability was isolated from a fish (anchovy) sauce. Strain MJ4 did not produce BAs from supplied precursors and no BA-producing genes were identified in its genome. Bacterial community analysis showed that in non-inoculated saeu-jeot (shrimp sauce) fermentation, Tetragenococcus predominated after 82 days, while in strain MJ4-inoculated saeu-jeot, Tetragenococcus predominated during the entire fermentation. Strain MJ4 repressed the growth of T. muriaticus, a known BA producer, during fermentation, but metabolite analysis demonstrated that metabolite profiles, including amino acids, were similar regardless of MJ4 inoculation. The metabolite analysis also showed that strain MJ4 clearly repressed the formation of cadaverine during fermentation. This study suggests that the use of strain MJ4 as a starter culture in salted fish fermentation may be a good strategy for the reduction of BA formation.
Topics: Amino Acids; Animals; Cadaverine; Crustacea; Enterococcaceae; Fermentation; Fermented Foods; Fish Products; Fishes; Food Microbiology; Microbiota; Seafood; Shellfish; Sodium Chloride
PubMed: 31027807
DOI: 10.1016/j.fm.2019.02.017