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International Journal of Molecular... Apr 2020An increasing number of studies have shown that the brain-gut-microbiota axis may significantly contribute to Alzheimer's disease (AD) pathogenesis. Moreover, impaired... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
An increasing number of studies have shown that the brain-gut-microbiota axis may significantly contribute to Alzheimer's disease (AD) pathogenesis. Moreover, impaired memory and learning involve the dysfunction neurotransmission of glutamate, the agonist of the -methyl-d-aspartate receptor and a major excitatory neurotransmitter in the brain. This systematic review aimed to summarize the current cutting-edge research on the gut microbiota and glutamate alterations associated with dementia.
METHODS
PubMed, the Cochrane Collaboration Central Register of Controlled Clinical Trials, and Cochrane Systematic Reviews were reviewed for all studies on glutamate and gut microbiota in dementia published up until Feb 2020.
RESULTS
Several pilot studies have reported alterations of gut microbiota and metabolites in AD patients and other forms of dementia. Gut microbiota including and affect glutamate metabolism and decrease the glutamate metabolite 2-keto-glutaramic acid. Meanwhile, gut bacteria with glutamate racemase including , and can convert l-glutamate to d-glutamate. N-methyl-d-aspartate glutamate receptor (NMDAR)-enhancing agents have been found to potentially improve cognition in AD or Parkinson's disease patients. These findings suggest that d-glutamate (d-form glutamate) metabolized by the gut bacteria may influence the glutamate NMDAR and cognitive function in dementia patients.
CONCLUSIONS
Gut microbiota and glutamate are potential novel interventions to be developed for dementia. Exploring comprehensive cognitive functions in animal and human trials with glutamate-related NMDAR enhancers are warranted to examine d-glutamate signaling efficacy in gut microbiota in patients with AD and other neurodegenerative dementias.
Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Brain; Diet; Disease Susceptibility; Gastrointestinal Microbiome; Glutamic Acid; Humans; Metabolic Networks and Pathways; Receptors, N-Methyl-D-Aspartate; Signal Transduction; Synaptic Transmission
PubMed: 32290475
DOI: 10.3390/ijms21082676 -
Revista Chilena de Infectologia :... Feb 2021
Topics: Actinomycetales Infections; Brevibacterium; Humans
PubMed: 33844798
DOI: 10.4067/S0716-10182021000100099 -
IDCases 2021Brevibacteria are Gram-positive rods found in human skin flora and dairy products. Although generally not considered human pathogens, case reports have implicated...
Brevibacteria are Gram-positive rods found in human skin flora and dairy products. Although generally not considered human pathogens, case reports have implicated species as rare causes of bacteremia, endocarditis, peritonitis, and osteomyelitis. We report a case of tibial osteomyelitis in an immunocompetent individual with implanted hardware and highlight the challenge of identifying the organism and recognizing it as a potential pathogen.
PubMed: 33511032
DOI: 10.1016/j.idcr.2021.e01046 -
Frontiers in Microbiology 2019Pyrethroids are broad-spectrum insecticides and presence of chiral carbon differentiates among various forms of pyrethroids. Microbial approaches have emerged as a... (Review)
Review
Pyrethroids are broad-spectrum insecticides and presence of chiral carbon differentiates among various forms of pyrethroids. Microbial approaches have emerged as a popular solution to counter pyrethroid toxicity to marine life and mammals. Bacterial and fungal strains can effectively degrade pyrethroids into non-toxic compounds. Different strains of bacteria and fungi such as spp., , sp., sp., sp., sp., sp., and spp., are used for the biodegradation of pyrethroids. Hydrolysis of ester bond by enzyme esterase/carboxyl esterase is the initial step in pyrethroid biodegradation. Esterase is found in bacteria, fungi, insect and mammalian liver microsome cells that indicates its hydrolysis ability in living cells. Biodegradation pattern and detected metabolites reveal microbial consumption of pyrethroids as carbon and nitrogen source. In this review, we aim to explore pyrethroid degrading strains, enzymes and metabolites produced by microbial strains. This review paper covers in-depth knowledge of pyrethroids and recommends possible solutions to minimize their environmental toxicity.
PubMed: 31428072
DOI: 10.3389/fmicb.2019.01778 -
Current Biology : CB Aug 2012
Topics: Brevibacterium; Cheese; Microbial Consortia; Odorants; Penicillium; Propionibacterium
PubMed: 22877773
DOI: 10.1016/j.cub.2012.06.014 -
Microorganisms Feb 2023-Caprolactam (Caprolactam, CAP), a monomer of the synthetic non-degradable polymer nylon-6, is the major wastewater component in the production of caprolactam and...
-Caprolactam (Caprolactam, CAP), a monomer of the synthetic non-degradable polymer nylon-6, is the major wastewater component in the production of caprolactam and nylon-6. Biological treatment of CAP, using microbes could be a potent alternative to the current waste utilization techniques. This work focuses on the characterization and potential use of caprolactam-degrading bacterial strain BS3 isolated from soils polluted by CAP production wastes. The strain was identified as based on the studies of its morphological, physiological, and biochemical properties and 16S rRNA gene sequence analysis. This study is the first to report the ability of to utilize CAP. Strain BS3 is an alcalo- and halotolerant organism, that grows within a broad range of CAP concentrations, from 0.5 up to 22.0 g/L, optimally at 1.0-2.0 g/L. A caprolactam biodegradation experiment using gas chromatography showed BS3 to degrade 1.0 g/L CAP over 160 h. In contrast to earlier characterized narrow-specific CAP-degrading bacteria, strain BS3 is also capable of utilizing linear nylon oligomers (oligomers of 6-aminohexanoic acid), CAP polymerization by-products, as sole sources of carbon and energy. The broad range of utilized toxic pollutants, the tolerance for high CAP concentrations, as well as the physiological properties of BS3, determine the prospects of its use for the biological cleanup of CAP and nylon-6 production wastes that contain CAP, 6-aminohexanoic acid, and low molecular weight oligomer fractions.
PubMed: 36838338
DOI: 10.3390/microorganisms11020373 -
IDCases 2017infection in man is rare. We report here the second case with isolation of in human. This micro-organism requires specific laboratory investigations such as 16S rRNA...
infection in man is rare. We report here the second case with isolation of in human. This micro-organism requires specific laboratory investigations such as 16S rRNA gene sequencing for accurate species identification. The clinical outcome was favorable.
PubMed: 28050348
DOI: 10.1016/j.idcr.2016.11.010 -
Scientific Reports Jul 2020The vaginal microbiota of healthy women typically has low diversity, which increases after perturbations. Among these, lifestyle associated with certain sexual and...
The vaginal microbiota of healthy women typically has low diversity, which increases after perturbations. Among these, lifestyle associated with certain sexual and antimicrobial practices may be associated with higher diversity. To test this hypothesis, we characterized the vaginal microbiota in the cervicovaginal and introital sites in sexually active Amerindians (N = 82) spanning urbanization, and in urban mestizos (N = 29), in the Venezuelan Amazonas. HPV status was also considered. Sampling was performed in an urban gradient from remote villages to a town, and women were individually classified by the degree of urbanization (low, medium, and high). Amerindian cervicovaginal and introital microbiota diversity were not associated with major changes in urbanization or ethnicity. There was a non-significant trend of increased diversity with urbanization, with a few taxa found overrepresented in urban Amerindians (Brevibacterium linens and Peptoniphilus lacrimalis) or mestizos (Mobiluncus mulieris and Prevotella sp.). Among all women, cervicovaginal and introital samples clustered, respectively, in four and two community state types (CSTs), where most profiles were dominated by Lactobacillus iners, Gardnerella vaginalis or were highly diverse profiles. HPV status did not associate with microbial diversity. In conclusion, no association was found between urban level and the vaginal microbiome in Amerindian women, and little difference was found between ethnicities. L. iners and high diversity profiles, associated with vaginal health outcomes, prevail in these populations.
Topics: Biodiversity; Cervix Uteri; Cluster Analysis; Female; Geography; Humans; Microbiota; Papillomavirus Infections; Urbanization; Vagina; Venezuela; American Indian or Alaska Native
PubMed: 32719372
DOI: 10.1038/s41598-020-69111-x -
The Journal of Antimicrobial... May 2024Corynebacterium (C.) sp. 22KM0430 related to C. oculi and isolated from a dog exhibited resistance to tetracycline, and its WGS analysis revealed a putative resistance...
BACKGROUND
Corynebacterium (C.) sp. 22KM0430 related to C. oculi and isolated from a dog exhibited resistance to tetracycline, and its WGS analysis revealed a putative resistance gene on a 35 562-bp plasmid also harbouring the MLSB resistance gene erm(X).
OBJECTIVES
To characterize the novel tetracycline resistance gene tet(65) and demonstrate its functionality by expression in C. glutamicum and Escherichia coli and plasmid curing of the host strain.
METHODS
tet(65) was cloned with and without its repressor tetR(65) and expressed in C. glutamicum DSM20300 and E. coli DH5α. Plasmid was cured by non-selective passages. Minimal inhibitory concentrations (MICs) of tetracyclines were determined according to CLSI guidelines. Association of tet(65) with efflux was shown by the addition of reserpine to MIC assays. Phylogenetic position and transmembrane structure of Tet(65) were analysed using MEGA11 and DeepTMHMM.
RESULTS
Tet(65) shows 73% amino acid identity with the closest related Tet(Z), contains 12 transmembrane domains and is structurally related to the Major Facilitator Superfamily. The tetracycline MICs decreased in the plasmid-cured strain and increased when tet(65) was expressed in C. glutamicum and in E. coli. The MICs of tetracycline decreased in the presence of reserpine indicating that tet(65) functions as an efflux pump. A GenBank search also identified tet(65) in C. diphtheriae and Brevibacterium (B.) casei and B. luteolum.
CONCLUSIONS
A novel tetracycline efflux gene tet(65) was identified in a C. oculi related species and was also present in the human pathogen C. diphtheriae and in Brevibacterium species indicating broader potential for dissemination.
Topics: Plasmids; Tetracycline Resistance; Microbial Sensitivity Tests; Anti-Bacterial Agents; Escherichia coli; Corynebacterium; Animals; Drug Resistance, Multiple, Bacterial; Phylogeny; Dogs; Tetracycline; Cloning, Molecular; Corynebacterium Infections; Dog Diseases
PubMed: 38497972
DOI: 10.1093/jac/dkae066 -
The Journal of Nutrition Oct 2004Studies on the production of L-arginine by fermentation using mutants of Corynebacterium (Brevibacterium), Bacillus, and Serratia have been conducted since the 1960s.... (Review)
Review
Studies on the production of L-arginine by fermentation using mutants of Corynebacterium (Brevibacterium), Bacillus, and Serratia have been conducted since the 1960s. More recently, the breeding of L-arginine production strains by gene recombination techniques using Escherichia coli has been investigated. To produce L-arginine efficiently by fermentation, it is necessary to breed strains with a strong biosynthetic pathway to L-arginine. Because L-arginine is biosynthesized from the precursor L-glutamic acid through ornithine and citrulline, the use of strains with a high capability for producing L-glutamic acid is desirable. Corynebacterium (Brevibacterium), which is well known in the production of L-glutamic acid, was selected as a starting strain for the breeding of an L-arginine producer and has been used on a commercial scale. Regarding the fermentation conditions, as for other amino acids, L-arginine fermentation is controlled by regulating pH near the neutral point. Due to its high oxygen requirement, L-arginine production is seriously impaired without sufficient oxygen. Advanced purification methods are necessary to obtain highly pure L-arginine from the fermentation broth. After fermentation is complete, bacterial cells and proteins are removed by means of a membrane or centrifugation, and impurities are removed by means of an ion-exchange resin or activated carbon. Highly pure L-arginine crystals can be obtained through concentration at the end of the process.
Topics: Arginine; Bacteria; Carbon Dioxide; Fermentation; Fungi; Oxygen
PubMed: 15465800
DOI: 10.1093/jn/134.10.2854S