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1.
Environ Monit Assess ; 196(2): 208, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38279971

RESUMO

The influence of anthropogenic pollution on the distribution of bacterial diversity, antibiotic-resistant bacteria (ARBs), and antibiotic resistance genes (ARGs) was mapped at various geo-tagged sites of Mini River, Vadodara, Gujarat, India. The high-throughput 16S rRNA gene amplicon sequencing analysis revealed a higher relative abundance of Planctomycetota at the polluted sites, compared to the pristine site. Moreover, the relative abundance of Actinobacteriota increased, whereas Chloroflexi decreased in the water samples of polluted sites than the pristine site. The annotation of functional genes in the metagenome samples of Mini River sites indicated the presence of genes involved in the defence mechanisms against bacitracin, aminoglycosides, cephalosporins, chloramphenicol, streptogramin, streptomycin, methicillin, and colicin. The analysis of antibiotic resistome at the polluted sites of Mini River revealed the abundance of sulfonamide, beta-lactam, and aminoglycoside resistance. The presence of pathogens and ARB was significantly higher in water and sediment samples of polluted sites compared to the pristine site. The highest resistance of bacterial populations in the Mini River was recorded against sulfonamide (≥ 7.943 × 103 CFU/mL) and ampicillin (≥ 8.128 × 103 CFU/mL). The real-time PCR-based quantification of ARGs revealed the highest abundance of sulfonamide resistance genes sul1 and sul2 at the polluted sites of the Mini River. Additionally, the antimicrobial resistance genes aac(6')-Ib-Cr and blaTEM were also found abundantly at polluted sites of the Mini River. The findings provide insights into how anthropogenic pollution drives the ARG and ARB distribution in the riverine ecosystem, which may help with the development of antimicrobial resistance mitigation strategies.


Assuntos
Antibacterianos , Genes Bacterianos , Antibacterianos/farmacologia , Antibacterianos/análise , Antagonistas de Receptores de Angiotensina/análise , RNA Ribossômico 16S/genética , Ecossistema , Monitoramento Ambiental , Inibidores da Enzima Conversora de Angiotensina/análise , Bactérias/genética , Sulfanilamida/análise , Água/análise
2.
Artigo em Inglês | MEDLINE | ID: mdl-37861831

RESUMO

Petroleum hydrocarbons and their derivatives constitute the leading group of environmental pollutants worldwide. In the present global scenario, petroleum and natural gas production, exploration, petroleum refining, and other anthropogenic activities produce huge amounts of hazardous petroleum wastes that accumulate in the terrestrial and marine environment. Due to their carcinogenic, neurotoxic, and mutagenic characteristics, petroleum pollutants pose severe risks to human health and exert ecotoxicological effects on the ecosystems. To mitigate petroleum hydrocarbons (PHs) contamination, implementing "green technologies" for effective cleanup and restoration of an affected environment is considered as a pragmatic approach. This review provides a comprehensive outline of newly emerging bioremediation technologies, for instance; nanobioremediation, electrokinetic bioremediation, vermiremediation, multifunctional and sustainably implemented on-site applied biotechnologies such as; natural attenuation, biostimulation, bioaugmentation, bioventing, phytoremediation and multi-process hybrid technologies. Additionally, the scope of the effectiveness and limitations of individual technologies in treating the petroleum hydrocarbon polluted sites are also evaluated.

4.
Biomedicines ; 10(12)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36552041

RESUMO

Alcoholic liver disease (ALD) alters gut microbiota and tight junctions, causing bacterial components to enter the portal vein and induce oxidative stress-induced inflammation in the liver. Only corticosteroids and liver transplants are treatment options for severe alcoholic hepatitis. ALD's pathophysiology is unknown. However, acetaldehyde's toxic effects cause oxidative stress and intestinal permeability. This study investigates the influence of a synbiotic (a combination of aged garlic extract (AGE) and Lactobacillus rhamnosus MTCC1423) on colonic oxidative stress and inflammation in ALD male Wistar rats and Caco2 cells. MDA measurement by HPLC in CaCo2 cells, blood serum, and colon tissue demonstrated that synbiotic treatment in the ALD model reduces oxidative stress. Further, fecal high-throughput 16S rRNA gene sequencing revealed the microbiome's shift towards Firmicutes in the synbiotic group compared to ethanol. In addition, DCFDA labeling and H/E staining demonstrate that the synbiotic is beneficial in inhibiting the development of ALD. In the colon, the synbiotic reduces the activation of CYP2E1 and the inflammatory markers TNF-a and IL-6 while elevating the mRNA expression of ZO-1, occludin, and IL-10. Synbiotics colonize Lactobacillus to restore barrier function and microbiota and reduce colon oxidative stress. Thus, a synbiotic combination can be used in ALD treatment.

5.
World J Microbiol Biotechnol ; 38(11): 212, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36053338

RESUMO

Rice straw decomposition is an attractive solution to open-field burning but the traditional method has slow kinetics and takes 60-90 days to obtain mature compost. In this study, we propose to boost up the decomposition process by addition of a novel microbial consortium rich in lignocellulolytic microbes. C: N ratio of the compost reached 11.69% and degradation efficiency of cellulose and hemicellulose was found to be 64 and 87% respectively within 25 days. Lignocellulolytic activity of the microbial consortium was confirmed by plate and activity assay. These parameters clearly indicated that a mature compost was obtained in 25 days. The 16S rRNA gene amplicon sequencing and functional analysis of predicted genes indicated amino acid and carbohydrate metabolism as the major metabolic pathway during composting. The tertiary level of functional analysis revealed the major metabolic pathways in the bacterial communities as pentose phosphate pathway, glycolysis and tricarboxylic acid cycle.


Assuntos
Compostagem , Microbiota , Oryza , Consórcios Microbianos/genética , Oryza/microbiologia , RNA Ribossômico 16S/genética , Solo/química
8.
Bioresour Technol ; 332: 125088, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33839511

RESUMO

This study evaluated the effect of bioaugmentation of a newly enriched electroactive bacterial community DC5 on the performance of a pilot scale sequential two-step Horizontal Sub-surface flow Constructed Wetland-Microbial Fuel Cell (HSCW-MFC) system treating textile dye wastewater. The system consisted of CW-MFC-1 planted with Fimbristylis ferruginea and CW-MFC-2 planted with consortium of Fimbristylis ferruginea and Elymus repens plant species. Before bioaugmentation, HSCW-MFC system showed 62 ± 2% Chemical Oxygen Demand (COD) and 90 ± 1.5% American Dye Manufacturer's Institute (ADMI) removal and 177.3 mW/m2 maximum power density (CW-MFC-1). After bioaugmentation of DC5 into the HSCW-MFC, COD and ADMI removal was enhanced to 74.10 ± 1.75% and 97.32 ± 1.90% with maximum power density of 197.94 mW/m2 (CW-MFC-1). The genera Exiguobacterium, Desulfovibrio and Macellibacteroides of DC5 were significantly enriched at the electrodes of HSCW-MFC after bioaugmentation. These results demonstrate that the performance of the CW-MFC treating textile dye wastewater can be improved by bioaugmentation of electroactive bacterial community.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Têxteis , Águas Residuárias , Áreas Alagadas
9.
Front Microbiol ; 11: 562813, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33224110

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are widespread across the globe mainly due to long-term anthropogenic sources of pollution. The inherent properties of PAHs such as heterocyclic aromatic ring structures, hydrophobicity, and thermostability have made them recalcitrant and highly persistent in the environment. PAH pollutants have been determined to be highly toxic, mutagenic, carcinogenic, teratogenic, and immunotoxicogenic to various life forms. Therefore, this review discusses the primary sources of PAH emissions, exposure routes, and toxic effects on humans, in particular. This review briefly summarizes the physical and chemical PAH remediation approaches such as membrane filtration, soil washing, adsorption, electrokinetic, thermal, oxidation, and photocatalytic treatments. This review provides a detailed systematic compilation of the eco-friendly biological treatment solutions for remediation of PAHs such as microbial remediation approaches using bacteria, archaea, fungi, algae, and co-cultures. In situ and ex situ biological treatments such as land farming, biostimulation, bioaugmentation, phytoremediation, bioreactor, and vermiremediation approaches are discussed in detail, and a summary of the factors affecting and limiting PAH bioremediation is also discussed. An overview of emerging technologies employing multi-process combinatorial treatment approaches is given, and newer concepts on generation of value-added by-products during PAH remediation are highlighted in this review.

10.
Front Microbiol ; 11: 576680, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072041

RESUMO

An efficient diazo dye degrading bacterial strain, Bacillus sp. DMS2 was isolated from a long-term textile dye polluted environment. The strain was assessed for its innate ability to completely degrade and detoxify Direct Red 81 (DR81) textile dye under microaerophilic conditions. The degradation ability of strain showed significant results on optimizing the nutritional and environmental parameters. Based on statistical models, maximum efficiency of decolorization achieved within 24 h for 100 mg/l of dye supplemented with glucose (0.02%), MgSO4 (0.002%) and urea (0.5%) at 30°C and pH (7.0). Moreover, a significant catabolic induction of a laccase and azoreductase suggested its vital role in degrading DR81 into three distinct metabolites (intermediates) as by-products. Further, toxicity analysis of intermediates were performed using seeds of common edible plants, aquatic plant (phytotoxicity) and the nematode model (animal toxicity), which confirmed the non-toxic nature of intermediates. Thus, the inclusive study of DMS2 showed promising efficiency in bioremediation approach for treating industrial effluents.

11.
J Hepatol ; 73(5): 1013-1022, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32540177

RESUMO

BACKGROUND & AIMS: The heterodimeric integrin receptor α4ß7 regulates CD4 T cell recruitment to inflamed tissues, but its role in the pathogenesis of non-alcoholic steatohepatitis (NASH) is unknown. Herein, we examined the role of α4ß7-mediated recruitment of CD4 T cells to the intestine and liver in NASH. METHODS: Male littermate F11r+/+ (control) and junctional adhesion molecule A knockout F11r-/- mice were fed a normal diet or a western diet (WD) for 8 weeks. Liver and intestinal tissues were analyzed by histology, quantitative reverse transcription PCR (qRT-PCR), 16s rRNA sequencing and flow cytometry. Colonic mucosa-associated microbiota were analyzed using 16s rRNA sequencing. Liver biopsies from patients with NASH were analyzed by confocal imaging and qRT-PCR. RESULTS: WD-fed knockout mice developed NASH and had increased hepatic and intestinal α4ß7+ CD4 T cells relative to control mice who developed mild hepatic steatosis. The increase in α4ß7+ CD4 T cells was associated with markedly higher expression of the α4ß7 ligand mucosal addressin cell adhesion molecule 1 (MAdCAM-1) in the colonic mucosa and livers of WD-fed knockout mice. Elevated MAdCAM-1 expression correlated with increased mucosa-associated Proteobacteria in the WD-fed knockout mice. Antibiotics reduced MAdCAM-1 expression indicating that the diet-altered microbiota promoted colonic and hepatic MAdCAM-1 expression. α4ß7 blockade in WD-fed knockout mice significantly decreased α4ß7+ CD4 T cell recruitment to the intestine and liver, attenuated hepatic inflammation and fibrosis, and improved metabolic indices. MAdCAM-1 blockade also reduced hepatic inflammation and fibrosis in WD-fed knockout mice. Hepatic MAdCAM-1 expression was elevated in patients with NASH and correlated with higher expression of α4 and ß7 integrins. CONCLUSIONS: These findings establish α4ß7/MAdCAM-1 as a critical axis regulating NASH development through colonic and hepatic CD4 T cell recruitment. LAY SUMMARY: Non-alcoholic steatohepatitis (NASH) is an advanced and progressive form of non-alcoholic fatty liver disease (NAFLD), and despite its growing incidence no therapies currently exist to halt NAFLD progression. Herein, we show that blocking integrin receptor α4ß7-mediated recruitment of CD4 T cells to the intestine and liver not only attenuates hepatic inflammation and fibrosis, but also improves metabolic derangements associated with NASH. These findings provide evidence for the potential therapeutic application of α4ß7 antibody in the treatment of human NASH.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Dieta Ocidental/efeitos adversos , Integrinas/metabolismo , Mucosa Intestinal/imunologia , Fígado/imunologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Linfócitos T CD4-Positivos/metabolismo , Moléculas de Adesão Celular/antagonistas & inibidores , Moléculas de Adesão Celular/deficiência , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Modelos Animais de Doenças , Microbioma Gastrointestinal/genética , Humanos , Integrinas/antagonistas & inibidores , Integrinas/imunologia , Fígado/patologia , Masculino , Camundongos , Camundongos Knockout , Mucoproteínas/antagonistas & inibidores , Mucoproteínas/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia , RNA Ribossômico 16S/genética , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/genética
12.
FASEB J ; 34(5): 7089-7102, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32275114

RESUMO

There is compelling evidence implicating intestinal permeability in the pathogenesis of nonalcoholic steatohepatitis (NASH), but the underlying mechanisms remain poorly understood. Here we examined the role of bile acids (BA) in western diet (WD)-induced loss of colonic epithelial barrier (CEB) function in mice with a genetic impairment in intestinal epithelial barrier function, junctional adhesion molecule A knockout mice, F11r-/- . WD-fed knockout mice developed severe NASH, which was associated with increased BA concentration in the cecum and loss of CEB function. Analysis of cecal BA composition revealed selective increases in primary unconjugated BAs in the WD-fed mice, which correlated with increased abundance of microbial taxa linked to BA metabolism. In vitro permeability assays revealed that chenodeoxycholic acid (CDCA), which was elevated in the cecum of WD-fed mice, increased paracellular permeability, while the BA-binding resin sevelamer hydrochloride protected against CDCA-induced loss of barrier function. Sequestration of intestinal BAs by in vivo delivery of sevelamer to WD-fed knockout mice attenuated colonic mucosal inflammation and improved CEB. Sevelamer also reduced hepatic inflammation and fibrosis, and improved metabolic derangements associated with NASH. Collectively, these findings highlight a hitherto unappreciated role for BAs in WD-induced impairment of the intestinal epithelial barrier in NASH.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colo/metabolismo , Dieta Ocidental/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Animais , Células CACO-2 , Moléculas de Adesão Celular/deficiência , Moléculas de Adesão Celular/genética , Colo/patologia , Modelos Animais de Doenças , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Permeabilidade , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/genética , Sevelamer/administração & dosagem
13.
Environ Sci Pollut Res Int ; 27(22): 27330-27344, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31332685

RESUMO

This study evaluated Cr(VI) biosorption by a halotolerant gram-negative bacterium Halomonas sp. DK4 isolated from chrome electroplating sludge. The bacterium could withstand high concentrations of Cr(VI) exhibiting a minimal inhibitory concentration (MIC) of 250 mg/L. Plackett-Burman design confirmed glucose, KH2PO4, NaCl, inoculum size, and initial Cr(VI) concentration as significant variables influencing the Cr(VI) removal ability of the bacterium. The suspended culture of Halomonas sp. DK4 was able to remove 81% (100 mg/L) of Cr(VI) in optimized MSM medium from aqueous solutions within 48 h. The bacterium also removed 59% Cr(VI) in the presence of 15% NaCl concentration within 72 h. The main mechanism involved in Cr(VI) removal by Halomonas sp. DK4 was determined to be biosorption which was best explained using the Langmuir isotherm model, wherein the maximum adsorption of 150.7 mg/g was observed under equilibrium conditions. Kinetic studies reveal that chemisorption of Cr(VI) by Halomonas sp. DK4 was a rate-limiting process which followed pseudo-second-order kinetics (R2 = 0.99). Bacterial biomass exhibited maximum adsorption of 70.3% Cr(VI) at an initial concentration of 100 mg/L under optimal conditions. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the presence of hydroxyl, carboxyl, amide, and phosphate groups on the bacterial surface which may be involved in Cr(VI) adsorption. Scanning electron microscopy coupled energy dispersive X-ray (SEM-EDX) analysis revealed morphological changes in the bacterial cell and accumulation of Cr(VI) on the cell surface. These results suggest the potential application of Halomonas sp. DK4 in the removal of Cr(VI) from saline chromium-containing industrial wastewaters.


Assuntos
Halomonas , Poluentes Químicos da Água , Adsorção , Cromo , Galvanoplastia , Concentração de Íons de Hidrogênio , Cinética , Esgotos
14.
J Environ Manage ; 250: 109549, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31545178

RESUMO

Treatment of raw textile effluent (RTE) is very difficult, due to its inherent heterogeneous, low-biodegradable and toxic compositions. Pure and mixed microbial cultures have limited metabolic capabilities in effective mineralization of complex RTE. Therefore, in this study a novel bacterial community DR4 was enriched directly into a complex RTE consisting of 27 different dyes using textile dye polluted soil as an inoculum. The rigorous enrichment process resulted in acclimatization of a taxonomically distinct bacterial population, with an abundance of the genus Comamonas in the bacterial community DR4 as compared to the abundance of Pseudomonas in the RTE respectively, as revealed by high-throughput 16S rRNA gene (V3-V4 region) sequencing. Microaerophilic treatment of RTE by enriched bacterial community DR4, in the presence of optimized electron donor (sucrose) and nitrogen source (yeast extract) resulted in 88% of American Dye Manufacturer's Institute (ADMI) removal and 98% of Chemical oxygen demand (COD) reduction within 32 h at 37 °C. In silico prediction of the functional genes within bacterial community DR4 was made by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. The PICRUSt analysis revealed high abundance of xenobiotic degradation and metabolism genes. The predicted functional genes and textile dye degradation pathways were further validated using Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy and High Resolution Liquid Chromatography coupled with Mass Spectrometry (HR-LCMS) based characterization of textile dye degradation metabolites. The activity of azoreductases in the cell-free extracts (CFE) of the enriched bacterial community DR4 was induced by 1.83-7.81 folds in the presence of representative textile dyes as compared to uninduced samples, which confirmed their role in textile effluent decolourization. The degradation of four representative azo dyes present in RTE such as Disperse orange 30, Reactive red 152, Direct blue 2 and Acid brown 15 depicted symmetric degradation of azo bonds by bacterial community DR4.


Assuntos
Indústria Têxtil , Têxteis , Compostos Azo , Biodegradação Ambiental , Corantes , Filogenia , RNA Ribossômico 16S , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Bioresour Technol ; 285: 121349, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31004945

RESUMO

This work studied eco-electrogenic treatment of real dyestuff wastewater along with characterization of electrode-enriched microbial community structures in Fimbristylis dichotoma planted closed-circuit constructed wetland-microbial fuel cell (CW-MFC) system. The CW-MFC-2 (experimental system) achieved 82.2 ±â€¯1.7% ADMI removal and 70 ±â€¯2% COD reduction; that were found to be 9% and 7.4% higher than the standalone constructed wetland (CW) system (bioremediation control) respectively. Likewise, the CW-MFC-2 system achieved maximum power density of 198.8 mW/m2, which was 85.6 ±â€¯2.47% higher than the CW-MFC-1 system (eco-electricity control). Quantitative reverse transcription PCR (qRT-PCR) assays revealed significant down-regulation of hepatic oxidative stress response biomarker genes in Oreochromis niloticus exposed to CW-MFC-2 system treated dyestuff wastewater as compared with untreated wastewater. The biofilms associated with the anode and cathode of the CW-MFC-2 system exhibited selective enrichment of electrochemically active and dye degrading microbial communities.


Assuntos
Fontes de Energia Bioelétrica , Microbiota , Eletricidade , Eletrodos , Águas Residuárias , Áreas Alagadas
16.
Nat Microbiol ; 1: 15021, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-27571978

RESUMO

The mammalian intestine houses a complex microbial community, which influences normal epithelial growth and development, and is integral to the repair of damaged intestinal mucosa(1-3). Restitution of injured mucosa involves the recruitment of immune cells, epithelial migration and proliferation(4,5). Although microenvironmental alterations have been described in wound healing(6), a role for extrinsic influences, such as members of the microbiota, has not been reported. Here, we show that a distinct subpopulation of the normal mucosal-associated gut microbiota expands and preferentially colonizes sites of damaged murine mucosa in response to local environmental cues. Our results demonstrate that formyl peptide receptor 1 (FPR1) and neutrophilic NADPH oxidase (NOX2) are required for the rapid depletion of microenvironmental oxygen and compensatory responses, resulting in a dramatic enrichment of an anaerobic bacterial consortium. Furthermore, the dominant member of this wound-mucosa-associated microbiota, Akkermansia muciniphila (an anaerobic, mucinophilic gut symbiont(7,8)), stimulated proliferation and migration of enterocytes adjacent to the colonic wounds in a process involving FPR1 and intestinal epithelial-cell-specific NOX1-dependent redox signalling. These findings thus demonstrate how wound microenvironments induce the rapid emergence of 'probiont' species that contribute to enhanced repair of mucosal wounds. Such microorganisms could be exploited as potential therapeutics.


Assuntos
Bactérias Anaeróbias/crescimento & desenvolvimento , Microbioma Gastrointestinal , Mucosa Intestinal/lesões , Mucosa Intestinal/microbiologia , Ferimentos e Lesões/microbiologia , Anaerobiose , Animais , Movimento Celular , Proliferação de Células , Enterócitos/fisiologia , Camundongos , NADPH Oxidase 1/metabolismo , NADPH Oxidase 2/metabolismo , Receptores de Formil Peptídeo/metabolismo
17.
Gastroenterology ; 151(4): 733-746.e12, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27342212

RESUMO

BACKGROUND & AIMS: There is evidence from clinical studies that compromised intestinal epithelial permeability contributes to the development of nonalcoholic steatohepatitis (NASH), but the exact mechanisms are not clear. Mice with disruption of the gene (F11r) encoding junctional adhesion molecule A (JAM-A) have defects in intestinal epithelial permeability. We used these mice to study how disruption of the intestinal epithelial barrier contributes to NASH. METHODS: Male C57BL/6 (control) or F11r(-/-) mice were fed a normal diet or a diet high in saturated fat, fructose, and cholesterol (HFCD) for 8 weeks. Liver and intestinal tissues were collected and analyzed by histology, quantitative reverse-transcription polymerase chain reaction, and flow cytometry. Intestinal epithelial permeability was assessed in mice by measuring permeability to fluorescently labeled dextran. The intestinal microbiota were analyzed using 16S ribosomal RNA sequencing. We also analyzed biopsy specimens from proximal colons of 30 patients with nonalcoholic fatty liver disease (NAFLD) and 19 subjects without NAFLD (controls) undergoing surveillance colonoscopy. RESULTS: F11r(-/-) mice fed a HFCD, but not a normal diet, developed histologic and pathologic features of severe NASH including steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis, whereas control mice fed a HFCD developed only modest steatosis. Interestingly, there were no differences in body weight, ratio of liver weight:body weight, or glucose homeostasis between control and F11r(-/-) mice fed a HFCD. In these mice, liver injury was associated with significant increases in mucosal inflammation, tight junction disruption, and intestinal epithelial permeability to bacterial endotoxins, compared with control mice or F11r(-/-) mice fed a normal diet. The HFCD led to a significant increase in inflammatory microbial taxa in F11r(-/-) mice, compared with control mice. Administration of oral antibiotics or sequestration of bacterial endotoxins with sevelamer hydrochloride reduced mucosal inflammation and restored normal liver histology in F11r(-/-) mice fed a HFCD. Protein and transcript levels of JAM-A were significantly lower in the intestinal mucosa of patients with NAFLD than without NAFLD; decreased expression of JAM-A correlated with increased mucosal inflammation. CONCLUSIONS: Mice with defects in intestinal epithelial permeability develop more severe steatohepatitis after a HFCD than control mice, and colon tissues from patients with NAFLD have lower levels of JAM-A and higher levels of inflammation than subjects without NAFLD. These findings indicate that intestinal epithelial barrier function and microbial dysbiosis contribute to the development of NASH. Restoration of intestinal barrier integrity and manipulation of gut microbiota might be developed as therapeutic strategies for patients with NASH.


Assuntos
Moléculas de Adesão Celular/deficiência , Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/genética , Receptores de Superfície Celular/deficiência , Animais , Colesterol , Dieta Hiperlipídica/métodos , Carboidratos da Dieta , Modelos Animais de Doenças , Disbiose/complicações , Disbiose/genética , Frutose , Microbioma Gastrointestinal/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Permeabilidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Cell Rep ; 12(8): 1217-25, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26279578

RESUMO

An optimal gut microbiota influences many beneficial processes in the metazoan host. However, the molecular mechanisms that mediate and function in symbiont-induced host responses have not yet been fully characterized. Here, we report that cellular ROS enzymatically generated in response to contact with lactobacilli in both mice and Drosophila has salutary effects against exogenous insults to the intestinal epithelium via the activation of Nrf2 responsive cytoprotective genes. These data show that the xenobiotic-inducible Nrf2 pathway participates as a signaling conduit between the prokaryotic symbiont and the eukaryotic host. Indeed, our data imply that the capacity of lactobacilli to induce redox signaling in epithelial cells is a highly conserved hormetic adaptation to impel cellular conditioning to exogenous biotic stimuli. These data also highlight the role the microbiota plays in eukaryotic cytoprotective pathways and may have significant implications in the characterization of a eubiotic microbiota.


Assuntos
Drosophila/metabolismo , Mucosa Intestinal/metabolismo , Lacticaseibacillus rhamnosus/metabolismo , Lactobacillus plantarum/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Drosophila/microbiologia , Mucosa Intestinal/microbiologia , Lactobacillus plantarum/patogenicidade , Lacticaseibacillus rhamnosus/patogenicidade , Camundongos , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Transdução de Sinais
19.
Eukaryot Cell ; 13(4): 452-60, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24489039

RESUMO

Prokaryotes and lower eukaryotes, such as yeasts, utilize two-component signal transduction pathways to adapt cells to environmental stress and to regulate the expression of genes associated with virulence. One of the central proteins in this type of signaling mechanism is the phosphohistidine intermediate protein Ypd1. Ypd1 is reported to be essential for viability in the model yeast Saccharomyces cerevisiae. We present data here showing that this is not the case for Candida albicans. Disruption of YPD1 causes cells to flocculate and filament constitutively under conditions that favor growth in yeast form. To determine the function of Ypd1 in the Hog1 mitogen-activated protein kinase (MAPK) pathway, we measured phosphorylation of Hog1 MAPK in ypd1Δ/Δ and wild-type strains of C. albicans. Constitutive phosphorylation of Hog1 was observed in the ypd1Δ/Δ strain compared to the wild-type strain. Furthermore, fluorescence microscopy revealed that green fluorescent protein (GFP)-tagged Ypd1 is localized to both the nucleus and the cytoplasm. The subcellular segregation of GFP-tagged Ypd1 hints at an important role(s) of Ypd1 in regulation of Ssk1 (cytosolic) and Skn7 (nuclear) response regulator proteins via phosphorylation in C. albicans. Overall, our findings have profound implications for a mechanistic understanding of two-component signaling pathways in C. albicans, and perhaps in other pathogenic fungi.


Assuntos
Candida albicans/genética , Regulação Fúngica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Quinases/genética , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais , Sequência de Aminoácidos , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Deleção de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Viabilidade Microbiana , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Dados de Sequência Molecular , Fosforilação , Proteínas Quinases/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos
20.
Sex Health ; 10(4): 320-4, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23702272

RESUMO

UNLABELLED: Background Trichomonas vaginalis is the world's most common treatable sexually transmissible infection. Currently, wet mount microscopy and syndromic management based on vaginal discharge are the most widely used methods for diagnosing and treating trichomoniasis in resource-constrained settings. Wet mount microscopy requires equipment and trained technicians, who are in short supply. We examined the diagnostic accuracy of the OSOM Trichomonas Rapid Test for detecting T. vaginalis vaginal infection among women in Mysore, India. METHODS: During July 2009-August 2010, 450 sexually active women over 18 years seeking care at an urban reproductive health clinic were enrolled in the study. Clinician-collected vaginal swabs were evaluated for trichomonads using wet mount microscopy, InPouch culture and the OSOM test. RESULTS: Of the 418 samples included in the analyses, culture detected 68 (16.3%) positive samples, wet mount microscopy detected 56 of the culture-positive samples and four false positive samples. The OSOM test detected 60 of the culture-positive samples plus two false positive cases. Using the composite reference standard (CRS), defined as wet mount- or culture-positive, the sensitivities of wet mount, the OSOM test and culture were 83.3%, 86.1% and 94.4%, respectively. The positive and negative predictive values of the OSOM test were 100% and 97.1% respectively. The Cohen's kappa agreement between the OSOM test and the CRS was excellent (κ=0.94). CONCLUSION: The OSOM test has high sensitivity, excellent specificity, and excellent positive and negative predictive value compared to a CRS. This simple test can improve screening and diagnosis of T. vaginalis infection in resource-constrained settings where microscopy and culture are unavailable.


Assuntos
Vaginite por Trichomonas , Trichomonas vaginalis , Feminino , Humanos , Sensibilidade e Especificidade , Trichomonas , Tricomoníase , Vaginite por Trichomonas/diagnóstico
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