-
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 -
BMC Cancer Oct 2022Microbiome dysbiosis is an important contributing factor in tumor development and thus may be a risk predictor for human malignancies. In the United States, women with...
BACKGROUNDS
Microbiome dysbiosis is an important contributing factor in tumor development and thus may be a risk predictor for human malignancies. In the United States, women with Hispanic/Latina (HIS) and African American (AA) background have a higher incidence of cervical cancer and poorer outcomes than Caucasian American (CA) women.
METHODS
Here, we assessed the distribution pattern of microbiota in cervical intraepithelial neoplasia (CIN) lesions obtained from HIS (n = 12), AA (n = 12), and CA (n = 12) women, who were screened for CC risk assessment. We employed a 16S rRNA gene sequencing approach adapted from the NIH-Human Microbiome Project to identify the microbial niche in all CIN lesions (n = 36).
RESULTS
We detected an appreciably decreased abundance of beneficial Lactobacillus in the CIN lesions of the AA and HIS women compared to the CA women. Differential abundance of potentially pathogenic Prevotella, Delftia, Gardnerella, and Fastidiosipila was also evident among the various racial groups. An increased abundance of Micrococcus was also evident in AA and HIS women compared to the CA women. The detection level of Rhizobium was higher among the AA ad CA women compared to the HIS women. In addition to the top 10 microbes, a unique niche of 27 microbes was identified exclusively in women with a histopathological diagnosis of CIN. Among these microbes, a group of 8 microbiota; Rubellimicrobium, Podobacter, Brevibacterium, Paracoccus, Atopobium, Brevundimonous, Comamonous, and Novospingobium was detected only in the CIN lesions obtained from AA and CA women.
CONCLUSIONS
Microbial dysbiosis in the cervical epithelium represented by an increased ratio of potentially pathogenic to beneficial microbes may be associated with increased CC risk disparities. Developing a race-specific reliable panel of microbial markers could be beneficial for CC risk assessment, disease prevention, and/or therapeutic guidance.
Topics: Female; Humans; Papillomaviridae; RNA, Ribosomal, 16S; Papillomavirus Infections; Dysbiosis; Uterine Cervical Neoplasms; Microbiota; Uterine Cervical Dysplasia
PubMed: 36258167
DOI: 10.1186/s12885-022-10112-6 -
Applied and Environmental Microbiology Dec 2022Chickens are in constant interaction with their environment, e.g., bedding and litter, and their microbiota. However, how litter microbiota develops over time and...
Chickens are in constant interaction with their environment, e.g., bedding and litter, and their microbiota. However, how litter microbiota develops over time and whether bedding and litter microbiota may affect the cecal microbiota is not clear. We addressed these questions using sequencing of V3/V4 variable region of 16S rRNA genes of cecal, bedding, and litter samples from broiler breeder chicken flocks for 4 months of production. Cecal, bedding, and litter samples were populated by microbiota of distinct composition. The microbiota in the bedding material did not expand in the litter. Similarly, major species from litter microbiota did not expand in the cecum. Only cecal microbiota was found in the litter forming approximately 20% of total litter microbiota. A time-dependent development of litter microbiota was observed. Escherichia coli, Staphylococcus saprophyticus, and Weissella jogaejeotgali were characteristic of fresh litter during the first month of production. Corynebacterium casei, Lactobacillus gasseri, and Lactobacillus salivarius dominated in a 2-month-old litter, , , and were characteristic for 3-month-old litter, and , , , and Staphylococcus lentus were common in a 4-month-old litter. Although the development was likely determined by physicochemical conditions in the litter, it might be interesting to test some of these species for active modification of litter to improve the chicken environment and welfare. Despite intimate contact, the composition of bedding, litter, and cecal microbiota differs considerably. Species characteristic for litter microbiota at different time points of chicken production were identified thus opening the possibility for active manipulation of litter microbiota.
Topics: Animals; Chickens; RNA, Ribosomal, 16S; Microbiota; Cecum
PubMed: 36468876
DOI: 10.1128/aem.01809-22 -
Biomacromolecules Dec 2021Encapsulin-based protein cages are nanoparticles with potential biomedical applications, such as targeted drug delivery or imaging. These particles are biocompatible and...
Encapsulin-based protein cages are nanoparticles with potential biomedical applications, such as targeted drug delivery or imaging. These particles are biocompatible and can be produced in bacteria, allowing large-scale production and protein engineering. In order to use these bacterial nanocages in different applications, it is important to further explore their surface modification and optimize their production. In this study, we design and show new surface modifications of (Tm) and (Bl) encapsulins. Two new loops on the Tm encapsulin with a His-tag insertion after residue 64 and residue 127 and the modification of the C-terminus on the Bl encapsulin are reported. The multimodification of the Tm encapsulin enables up to 240 functionalities on the cage surface, resulting from four potential modifications per protein subunit. We further report an improved production protocol giving a better stability and good production yield of the cages. Finally, we tested the stability of different encapsulin variants over a year, and the results show a difference in stability arising from the tag insertion position. These first insights in the structure-property relationship of encapsulins, with respect to the position of a functional loop, allow for further study of the use of these protein nanocages in biomedical applications.
Topics: Bacterial Proteins; Drug Delivery Systems; Nanoparticles; Protein Engineering; Thermotoga maritima
PubMed: 34747611
DOI: 10.1021/acs.biomac.1c01156 -
Journal of Cancer Research and... Aug 2023This study aimed to investigate the differences in the composition of microbial communities and related functions in hepatocellular carcinoma (HCC) tumours and matched...
AIMS
This study aimed to investigate the differences in the composition of microbial communities and related functions in hepatocellular carcinoma (HCC) tumours and matched normal tissues were investigated.
METHODS AND MATERIAL
Tumour tissues and matched normal samples were collected from 30 HCC patients. Genomic DNA was collected and subjected to sequencing of the V3 + V4 region of the 16S rRNA gene. The microbial community profiles and metabolic pathway predictions of the different groups were characterized and compared.
RESULTS
Tumour and adjacent tissues had similar microbiota compositions but differed in abundance. Proteobacteria and Firmicutes abundance decreased and Cyanobacteria and Acidobacteria abundance increased in the tumour tissue. The microbial community diversity was higher in the tumour tissues than in adjacent samples, with potentially more dominant taxa in the adjacent tissues, including Firmicutes, Proteobacteria, and Actinobacteria. Acidobacteria, Cyanobacteria, and Chloroflexi were the dominant microbes in tumour tissues. A total of 46 metabolic pathways were identified. Global and overview maps were the most abundant pathways, followed by carbohydrate metabolism, energy metabolism, metabolism of cofactors and vitamins, and membrane transport. The top 50 most highly correlated microbial genera included Klebsiella, Rhodococcus, Ochrobactrum, and Azoarcus. Fonticella, Haloimpatiens, Brevibacterium, and Acidothermus were positively correlated with other microbial genera. The microbiota of adjacent tissues was more robust in the network analysis.
CONCLUSIONS
This study revealed differences in microbial composition between HCC tumour tissues and normal tissues and differences in microbial abundance associated with different metabolic functions. Cyanobacteria, Proteobacteria, and Actinobacteria may play important roles in HCC.
Topics: Humans; Carcinoma, Hepatocellular; RNA, Ribosomal, 16S; Liver Neoplasms; Energy Metabolism
PubMed: 37675712
DOI: 10.4103/jcrt.jcrt_139_22 -
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 -
International Journal of Molecular... Jul 2022Coumarin is highly distributed in nature, notably in higher plants. The biological features of coumarin include antibacterial, anticancer and antioxidant effects. It is...
Coumarin is highly distributed in nature, notably in higher plants. The biological features of coumarin include antibacterial, anticancer and antioxidant effects. It is well known that metal ions present in complexes accelerate the drug action and the efficacy of organic therapeutic agents. The main aim of the current study is the synthesis of different complexes of the interaction between ciprofloxacin hydrochloride (CIP) and coumarin derivative 7-hydroxy-4-methylcoumarin (HMC) with Zr(IV). The chelates of CIP with Zr(IV) were prepared and characterized by elemental analysis, melting point, conductance measurements, spectroscopic techniques involving IR, UV-Vis, H NMR, and thermal behavior (TG-DTG) in the presence of HMC, dimethylformamide (DMF), pyridine (Py), and triethylamine (EtN). Results of molar conductivity tests showed that the new synthesized complexes are electrolytes with a 1:1 or 1:2 electrolyte ratio, with the chloride ions functioning as counter ions. According to IR spectra, CIP acts as a neutral bidentate ligand with Zr(IV) through one carboxylato oxygen and the carbonyl group, HMC as a monodentate through the carbonyl group, and DMF through the oxygen atom of the carbonyl group and the N atom of Py and EtN. The thermal behavior of the complexes was carefully investigated using TG and DTG techniques. TG findings signal that water molecules are found as hydrated and coordinated. The thermal decomposition mechanisms proposed for CIP, HMC, and Zr(IV) complexes are discussed and the activation energies (E), Gibbs free energies (∆G*), entropies (∆S*), and enthalpies (∆H*) of thermal decomposition reactions have been calculated using Coats-Redfern (CR) and Horowitz-Metzeger (HM) methods. The studied complexes were tested against some human pathogens and phytopathogens, including three Gram-positive bacteria (, , ) and three Gram-negative bacteria (, and ), and compared to the free CIP and HMC parent compounds.
Topics: Anti-Bacterial Agents; Bacteria; Ciprofloxacin; Coordination Complexes; Coumarins; Humans; Ions; Ligands; Microbial Sensitivity Tests; Oxygen; Spectrophotometry, Infrared
PubMed: 35887366
DOI: 10.3390/ijms23148019