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1.
Int J Biol Macromol ; 264(Pt 1): 130544, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38428778

RESUMO

Duchenne Muscular Dystrophy (DMD) is an X-linked recessive genetic disorder characterized by progressive and severe muscle weakening and degeneration. Among the various forms of muscular dystrophy, it stands out as one of the most common and impactful, predominantly affecting boys. The condition arises due to mutations in the dystrophin gene, a key player in maintaining the structure and function of muscle fibers. The manuscript explores the structural features of dystrophin protein and their pivotal roles in DMD. We present an in-depth analysis of promising therapeutic approaches targeting dystrophin and their implications for the therapeutic management of DMD. Several therapies aiming to restore dystrophin protein or address secondary pathology have obtained regulatory approval, and many others are ongoing clinical development. Notably, recent advancements in genetic approaches have demonstrated the potential to restore partially functional dystrophin forms. The review also provides a comprehensive overview of the status of clinical trials for major therapeutic genetic approaches for DMD. In addition, we have summarized the ongoing therapeutic approaches and advanced mechanisms of action for dystrophin restoration and the challenges associated with DMD therapeutics.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X , Distrofia Muscular de Duchenne , Masculino , Humanos , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Distrofia Muscular de Duchenne/patologia , Distrofina/genética , Distrofina/metabolismo , Distrofina/uso terapêutico , Fibras Musculares Esqueléticas/metabolismo
2.
Mol Neurobiol ; 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38165583

RESUMO

Duchenne muscular dystrophy (DMD) is a genetic disorder that causes muscle weakness and degeneration. In this study, we identified potential biomarkers and drug targets for DMD through a comprehensive meta-analysis of mRNA profiles. We conducted an in-depth analysis of three microarray datasets from the GEO database, utilizing the Affymetrix platform. A rigorous data pre-processing pipeline encompassed background correction, normalization, log2 transformation and probe-to-gene symbol mapping. Robust multi-array average method followed by Limma package in R was employed to ensure differential expression analysis within individual datasets, yielding gene-specific p-values. We identified 63 genes exhibiting statistically significant differential expression across the three datasets (p < 0.05) and an absolute log fold change > 1.5. Functional enrichment analyses of these differentially expressed genes were done, followed by pathway analyses. Our results suggested pertinent biological processes, molecular functions and cellular components associated with DMD. Finally, eight hub genes-COL6A3, COL1A1, COL3A1, COL1A2, POSTN, TIMP1, THBS2 and SPP1-were pinpointed as central players in the network. Two differentially expressed genes with substantial absolute log-fold changes, namely, DMD, downregulated and MYH3, upregulated, were identified as potential therapeutic candidates. In light of these findings, our work contributes not only to understanding DMD at the molecular level but also presents potential targets for therapeutic strategies. Finally, our study facilitates the development of therapeutic interventions that can effectively control and mitigate the impact of DMD.

3.
J Biomol Struct Dyn ; 42(6): 3193-3203, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37184152

RESUMO

3'-phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1) is an enzyme that critically synthesises the biologically active form of sulfate (PAPS) for all sulfation reactions. The discovery of PAPSS1 as a possible drug target for cancer therapy, specifically in non-small cell lung cancer, has prompted us to investigate potential small-molecule inhibitors of PAPSS1. Here, a structure-based virtual screening method was used to search for phytochemicals in the IMPPAT database to find potential inhibitors of PAPSS1. The primary hits were selected based on their physicochemical, ADMET, and drug-like properties. Then, the binding affinities were calculated and analyzed the interactions to identify safer and more effective hits. The research identified two phytochemicals, Guggulsterone and Corylin, that exhibited significant affinity and specific interaction with the ATP-binding pocket of PAPSS1. Structural observations made by molecular docking were further accompanied by molecular dynamics (MD) simulations and principal component analysis (PCA) to examine the conformational changes and stability of PAPSS1 with the elucidated compounds Guggulsterone and Corylin. MD simulation results suggested that the binding of Guggulsterone and Corylin stabilizes the PAPSS1 structure, leading to fewer conformational changes. This implies that these compounds may be useful in developing PAPSS1 inhibitors for the therapeutic development against non-small cell lung cancer (NSCLC). This study highlights the potential of phytochemicals as PAPSS1 inhibitors and the utility of computational approaches in drug discovery.Communicated by Ramaswamy H. Sarma.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Compostos Fitoquímicos/farmacologia
4.
J Biomol Struct Dyn ; 42(4): 1846-1857, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37104027

RESUMO

Raf proto-oncogene serine/threonine kinase 1 (RAF1 or c-Raf) is a serine/threonine protein kinase crucial in regulating cell growth, differentiation, and survival. Any disruption or overexpression of RAF1 can result in neoplastic transformation and other disorders such as cardiomyopathy, Noonan syndrome, leopard syndrome, etc. RAF1 has been identified as a potential therapeutic target in drug development against various complex diseases, including cancer, due to its remarkable role in disease progression. Here, we carried out a multitier virtual screening study involving different in-silico approaches to discover potential inhibitors of RAF1. After applying the Lipinski rule of five, we retrieved all phytocompounds from the IMPPAT database based on their physicochemical properties. We performed a molecular docking-based virtual screening and got top hits with the best binding affinity and ligand efficiency. Then we screened out the selected hits using the PAINS filter, ADMET properties, and other druglike features. Eventually, PASS evaluation identifies two phytocompounds, Moracin C and Tectochrysin, with appreciable anti-cancerous properties. Finally, all-atom molecular dynamics simulation (MDS) followed by interaction analysis was performed on the elucidated compounds in complex with RAF1 for 200 ns to investigate their time-evolution dynamics and interaction mechanism. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) and Dynamical Cross-Correlation Matrix (DCCM) analyses then followed these results from the simulated trajectories. According to the results, the elucidated compounds stabilize the RAF1 structure and lead to fewer conformational alterations. The results of the current study indicated that Moracin C and Tectochrysin could serve as potential inhibitors of RAF1 after required validation.Communicated by Ramaswamy H. Sarma.


Assuntos
Benzofuranos , Simulação de Dinâmica Molecular , Proteínas Serina-Treonina Quinases , Estilbenos , Proteínas Serina-Treonina Quinases/química , Simulação de Acoplamento Molecular , Desenvolvimento de Medicamentos , Serina
5.
J Biomol Struct Dyn ; : 1-26, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37776015

RESUMO

Lung cancer remains a formidable global health challenge, necessitating the exploration of novel therapeutic approaches. This study investigates the potential of Cuscuta reflexa Roxb. stem extract as an anticancer agent against human lung cancer, focusing on its antioxidative and ROS-dependent apoptotic effects. Utilizing a combination of network pharmacology and in-vitro experimental validation, we delineate the multifaceted molecular mechanisms underlying the observed effects. The antioxidant potential of C. reflexa stem extract was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS•+) and ferric reducing/antioxidant power (FRAP), hydroxyl free radical scavenging, reactive nitrogen oxide scavenging and super oxide anion radical scavenging assays. Furthermore, the antiproliferative and proapoptotic effect of C. reflexa stem extract was evaluated against A549 lung adenocarcinoma cell line using the consecrated sulforhodamine B (SBR) and Annexin V-PI assays. Additionally, the mitochondrial membrane potential (MMP) and the total reactive oxygen species (ROS) estimation assays were performed. As a result, network pharmacology analysis revealed a complex interaction network between the bioactive constituents of C. reflexa and key proteins implicated in lung cancer progression. The C. reflexa stem extract showed dose-dependent antioxidant activity against DPPH• (IC50 - 87.38 µg/mL), reactive nitrogen oxide (IC50 - 318.34 µg/mL), FRAP (IC50 - 359.96 µg/mL), hydroxy free radicals (IC50 - 526.12 µg/mL) than ABTS●+ (IC50 - 698.45 µg/mL) and super oxide anion (IC50 - 892.71 µg/mL) as well as cytotoxic activity against A549 cells (IC50 - 436.80 µg/mL). Observations of morphological features in treated cells have revealed hallmark of apoptosis properties. Furthermore, as a result of treatment with C. reflexa stem extract, ROS generation and mitochondrial depolarization were increased in A549 cells, suggesting that this treatment has significant apoptotic properties. . These findings highlight the potential utility of this natural extract as an innovative therapeutic strategy for lung cancer treatment. The integration of network pharmacology and experimental validation enhances our understanding of the underlying mechanisms and provide the way for further translational research.Communicated by Ramaswamy H. Sarma.

6.
OMICS ; 27(8): 393-401, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37624678

RESUMO

Kidney renal cell carcinoma (KIRC) is the most common type of renal cancer. Kidney malignancies have been ranked in the top 10 most frequently occurring cancers. KIRC is a prevalent malignancy with a poor prognosis. The disease has risen for the last 40 years, and robust biomarkers for KIRC are needed for precision/personalized medicine. In this bioinformatics study, we utilized genomic data of KIRC patients from The Cancer Genome Atlas for biomarker discovery. A total of 314 samples were used in this study. We identified many differentially expressed genes (DEGs) categorized as upregulated or downregulated. A protein-protein interaction network for the DEGs was then generated and analyzed using the Search Tool for the Retrieval of Interacting Genes plugin of Cytoscape. A set of 10 hub genes was selected based on the Maximum Clique Centrality score defined by the CytoHubba plugin. The elucidated set of genes, that is, CALCA, CRH, TH, CHAT, SLC18A3, FSHB, MYH6, CAV3, KCNA4, and GBX2, were then categorized as potential candidates to be explored as KIRC biomarkers. The survival analysis plots for each gene suggested that alterations in CHAT, CAV3, CRH, MYH6, SLC18A3, and FSHB resulted in decreased survival of KIRC patients. In all, the results suggest that genomic alterations in selected genes can be explored to inform biomarker discovery and for therapeutic predictions in KIRC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/genética , Genômica , Medicina de Precisão , Neoplasias Renais/genética , Rim
7.
J Biomol Struct Dyn ; : 1-13, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37403288

RESUMO

The Mast/Stem cell growth factor receptor Kit (c-Kit), a Proto-oncogene c-Kit, is a tyrosine-protein kinase involved in cell differentiation, proliferation, migration, and survival. Its role in developing certain cancers, particularly gastrointestinal stromal tumors (GISTs) and acute myeloid leukemia (AML), makes it an attractive therapeutic target. Several small molecule inhibitors targeting c-Kit have been developed and approved for clinical use. Recent studies have focused on identifying and optimizing natural compounds as c-Kit inhibitors employing virtual screening. Still, drug resistance, off-target side effects, and variability in patient response remain significant challenges. From this perspective, phytochemicals could be an important resource for discovering novel c-Kit inhibitors with less toxicity, improved efficacy, and high specificity. This study aimed to uncover possible c-Kit inhibitors by utilizing a structure-based virtual screening of active phytoconstituents from Indian medicinal plants. Through the screening stages, two promising candidates, Anilinonaphthalene and Licoflavonol, were chosen based on their drug-like features and ability to bind to c-Kit. These chosen candidates were subjected to all-atom molecular dynamics (MD) simulations to evaluate their stability and interaction with c-Kit. The selected compounds Anilinonaphthalene from Daucus carota and Licoflavonol from Glycyrrhiza glabra showed their potential to act as selective binding partners of c-Kit. Our results suggest that the identified phytoconstituents could serve as a starting point to develop novel c-Kit inhibitors for developing new and effective therapies against multiple cancers, including GISTs and AML. The use of virtual screening and MD simulations provides a rational approach to discovering potential drug candidates from natural sources.Communicated by Ramaswamy H. Sarma.

8.
J Biomol Struct Dyn ; 41(23): 14135-14151, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36943780

RESUMO

Traditional treatment of cancer has been plagued by a number of obstacles, such as multiple drug resistance, toxicity and financial constraints. In contrast, phytochemicals that modulate a variety of molecular mechanisms are garnering increasing interest in complementary and alternative medicine. Therefore, an approach based on network pharmacology was used in the present study to explore possible regulatory mechanisms of 6-shogaol as a potential treatment for cervical cancer (CC). A number of public databases were screened to collect information on the target genes of 6-shogaol (SuperPred, Targetnet, Swiss target prediction and PharmMapper), while targets pertaining to CC were taken from disease databases (DisGeNet and Genecards) and gene expression omnibus (GEO) provided expression datasets. With STRING and Cytoscape, protein-protein interactions (PPI) were generated and topology analysis along with CytoNCA were used to identify the Hub genes. The Gene Ontology (GO) database Enrichr was used to annotate the target proteins, while, using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, signaling pathway enrichment analysis was conducted. Molecular docking and survival analysis for the Hub genes revealed four genes (HSP90AA1, HRAS, ESR1 and EGFR) with lowest binding energy and majority of the Hub genes (EGFR, SRC, CASP-3, HSP90AA1, MTOR, MAPK-1, MDM2 and ESR1) were linked with the overall survival of CC patients. In conclusion, the present study provides the scientific evidence which strongly supports the use of 6-shogoal as an inhibitor of cellular proliferation, growth, migration as well as inducer of apoptosis via targeting the hub genes involved in the growth of CC.Communicated by Ramaswamy H. Sarma.


Assuntos
Medicamentos de Ervas Chinesas , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/genética , Simulação de Acoplamento Molecular , Farmacologia em Rede , Receptores ErbB
9.
J Biomol Struct Dyn ; 41(22): 12789-12797, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36644886

RESUMO

Sphingosine kinase 1 (SphK1) dysfunction is well-known to be linked to various severe diseases, including breast, lung, prostate, and hematological cancers. Due to its crucial function in the onset of cancer and its progression, it is considered a notable drug target for anticancer therapy. Small molecule inhibitors with high specificity and efficacy towards SphK1 are needed for their therapeutic use. In order to find possible SphK1 inhibitors, we conducted a stepwise structure-based virtual screening of plant-based molecules available from the IMPPAT library. A multi-step virtual screening, including physicochemical and ADMET evaluation, PAINS, molecular docking, PASS analysis followed by molecular dynamics (MD) simulation and principal component analysis, identifies two compounds, Gummadiol and Isoarboreol, against SphK1. All-atom MD simulations were performed for 100 ns which examined the structural changes and stability of the docked complexes in the aqueous environment. The time evolution data of structural deviations and compactness, PCA and free energy landscapes suggested that the binding of Gummadiol and Isoarboreol with SphK1 is considerably stable throughout the trajectory. The study highlighted the use of phytochemicals in anticancer therapeutics and presented Gummadiol and Isoarboreol as promising inhibitors of SphK1.Communicated by Ramaswamy H. Sarma.


Assuntos
Simulação de Dinâmica Molecular , Neoplasias , Humanos , Simulação de Acoplamento Molecular , Fosfotransferases (Aceptor do Grupo Álcool)/química , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo
10.
Life (Basel) ; 12(11)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36362911

RESUMO

Fungal infections caused by Candida species have attracted great interest due to their resistance to commercial antifungal agents. Essential oils from aromatic and medicinal plants have many bioactive compounds that are known for their important biological activities, mainly their antimicrobial effects. In the present study, we aimed to evaluate the antifungal ability of Elettaria cardamomum essential oil (EO) against different clinical Candida isolates. Then, we investigated the anti-phospholipase, anti-protease, and anti-biofilm activity of E. cardamomum EO against the selected isolates. Twenty-four Candida strains (clinical and reference) were tested for virulence factors such as biofilm formation, protease, and phospholipase activity. The minimum inhibitory (MIC) and fungicidal (MFC) concentrations of E. cardamomum were determined, and their effects were tested against all Candida strains. Our results revealed that E. cardamomum EO was rich in α-terpinyl acetate (56.5%), limonene (12.6%), and mentha-2.4(8)-diene (7.65%). The tested EO showed activity against all tested Candida strains in their planktonic form and against exoenzymes and biofilm production. Based on our findings, we promote the use of E. cardamomum EO as a treatment against clinical Candida isolates active on the virulence factors of this fungus.

11.
Polymers (Basel) ; 14(19)2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36235929

RESUMO

Recently, there has been significant interest in bio-based degradable plastics owing to their potential as a green and sustainable alternative to synthetic plastics due to their biodegradable properties. Polyhydroxybutyrate (PHB) is a biodegradable polymer that is produced by bacteria and archaea as carbon and energy reserves. Due to its rapid degradation in natural environments, it can be considered a biodegradable plastic alternative. In the present study, a dye-based procedure was used to screen PHB-producing bacteria isolated from mangrove soil samples. Among the seven isolates, Agromyces indicus (A. indicus), identified by means of 16S rRNA analysis, accumulated the highest amount of PHB. The extracted polymer was characterized by a UV-Vis spectrophotometer, Fourier-transform infrared (FTIR) spectroscopy, and for the presence of the phbB gene, which confirmed the structure of the polymer as PHB. The maximum PHB production by A. indicus was achieved after 96 h of incubation at a pH of 8.0 and 35 °C in the presence of 2% NaCl, with glucose and peptone as the carbon and nitrogen sources, respectively. The strain was found to be capable of accumulating PHB when various cheap agricultural wastes, such as rice, barley, corn, and wheat bran, were used as the carbon sources. The response surface methodology (RSM) through the central composite design (CCD) for optimizing the PHB synthesis was found to be highly efficient at augmenting the polymer yields. As a result of the optimum conditions obtained from the RSM, this strain can increase the PHB content by approximately 1.4-fold when compared with an unoptimized medium, which would substantially lower the production cost. Therefore, the isolate A. indicus strain B2 may be regarded as one of the best candidates for the industrial production of PHB from agricultural wastes, and it can remove the environmental concerns associated with synthetic plastic.

12.
Artigo em Inglês | MEDLINE | ID: mdl-35692581

RESUMO

In the present study, we investigated the cytotoxic effects of Athyrium hohenackerianum ethanolic extract (AHEE) on the proliferation of breast, lung, and colon cancer cells. The AHEE was tested for its effect on the progression of the cell cycle, followed by induction of apoptosis determination by flow cytometry. Real-time qRT-PCR was also utilized to observe the initiation of apoptosis. In addition, GC-MS was performed in order to identify the active phytochemicals present in the AHEE. A cytotoxic activity with an IC50 value of 123.90 µg/mL against HCT-116 colon cancer cells was exhibited by AHEE. Following propidium iodide staining, annexin-V/PI, and clonogenic assays, AHEE treatment results in cell arrest in the S phase, causing an increase in the early and late phases of apoptosis and displaying antiproliferative potential, respectively. The morphological alterations were further monitored using acridine orange/ethidium bromide (AO/EB) staining. When compared with the control cells, features of apoptotic cell death, including nuclear fragmentation, in the AHEE-treated cells were noticed. The apoptosis was also confirmed by detecting the increased expression of p53 and caspase-3 along with the downregulation of Bcl-2. GC-MS analysis revealed that trans-linalool oxide, loliolide, phytol, 4,8,12,16-tetramethylheptadecan-4-olide, and gamma-sitosterol were the major phytochemical constituents. Based on these findings, it can be suggested that AHEE causes cellular death via apoptosis, which should be further explored for the identification of active compounds responsible for these observed effects. Therefore, AHEE can be used in the pharmaceutical development of anticancer agents for cancer therapeutics.

13.
Front Oncol ; 12: 869672, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35402265

RESUMO

Non-small cell lung carcinoma (NSCLC) comprises 80%-85% of lung cancer cases. EGFR is involved in several cancer developments, including NSCLC. The EGFR pathway regulates the Bax/Bcl-2 cascade in NSCLC. Increasing understanding of the molecular mechanisms of fundamental tumor progression has guided the development of numerous antitumor drugs. The development and improvement of rationally planned inhibitors and agents targeting particular cellular and biological pathways in cancer have been signified as a most important paradigm shift in the strategy to treat and manage lung cancer. Newer approaches and novel chemotherapeutic agents are required to accompany present cancer therapies for improving efficiency. Using natural products as a drug with an effective delivery system may benefit therapeutics. Naturally originated compounds such as phytochemicals provide crucial sources for novel agents/drugs and resources for tumor therapy. Applying the small-molecule inhibitors (SMIs)/phytochemicals has led to potent preclinical discoveries in various human tumor preclinical models, including lung cancer. In this review, we summarize recent information on the molecular mechanisms of the Bax/Bcl-2 cascade and EGFR pathway in NSCLC and target them for therapeutic implications. We further described the therapeutic potential of Bax/Bcl-2/EGFR SMIs, mainly those with more potent and selectivity, including gefitinib, EGCG, ABT-737, thymoquinone, quercetin, and venetoclax. In addition, we explained the targeting EGFR pathway and ongoing in vitro and in vivo and clinical investigations in NSCLC. Exploration of such inhibitors facilitates the future treatment and management of NSCLC.

14.
Microorganisms ; 10(3)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35336071

RESUMO

While it is reported that COVID-19 patients are more prone to secondary bacterial infections, which are strongly linked to the severity of complications of the disease, bacterial coinfections associated with COVID-19 are not widely studied. This work aimed to investigate the prevalence of bacterial coinfections and associated antibiotic resistance profiles among hospitalised COVID-19 patients. Age, gender, weight, bacterial identities, and antibiotic sensitivity profiles were collected retrospectively for 108 patients admitted to the intensive care unit (ICU) and non-ICU ward of a single center in Saudi Arabia. ICU patients (60%) showed a significantly higher percentage of bacterial coinfections in sputum (74%) and blood (38%) samples, compared to non-ICU. Acinetobacter baumannii (56%) and Klebsiella pneumoniae (56%) were the most prevalent bacterial species from ICU patients, presenting with full resistance to all tested antibiotics except colistin. By contrast, samples of non-ICU patients exhibited infections with Escherichia coli (31%) and Pseudomonas aeruginosa (15%) predominantly, with elevated resistance of E. coli to piperacillin/tazobactam and trimethoprim/sulfamethoxazole. This alarming correlation between multi-drug resistant bacterial coinfection and admission to the ICU requires more attention and precaution with prescribed antibiotics to limit the spread of resistant bacteria and improve therapeutic management.

15.
mBio ; 10(6)2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690672

RESUMO

Nitrification, the oxidative process converting ammonia to nitrite and nitrate, is driven by microbes and plays a central role in the global nitrogen cycle. Our earlier investigations based on 16S rRNA and amoA amplicon analysis, amoA quantitative PCR and metagenomics of groundwater-fed biofilters indicated a consistently high abundance of comammox Nitrospira Here, we hypothesized that these nonclassical nitrifiers drive ammonia-N oxidation. Hence, we used DNA and RNA stable isotope probing (SIP) coupled with 16S rRNA amplicon sequencing to identify the active members in the biofilter community when subjected to a continuous supply of NH4+ or NO2- in the presence of 13C-HCO3- (labeled) or 12C-HCO3- (unlabeled). Allylthiourea (ATU) and sodium chlorate were added to inhibit autotrophic ammonia- and nitrite-oxidizing bacteria, respectively. Our results confirmed that lineage II Nitrospira dominated ammonia oxidation in the biofilter community. A total of 78 (8 by RNA-SIP and 70 by DNA-SIP) and 96 (25 by RNA-SIP and 71 by DNA-SIP) Nitrospira phylotypes (at 99% 16S rRNA sequence similarity) were identified as complete ammonia- and nitrite-oxidizing, respectively. We also detected significant HCO3- uptake by Acidobacteria subgroup10, Pedomicrobium, Rhizobacter, and Acidovorax under conditions that favored ammonia oxidation. Canonical Nitrospira alone drove nitrite oxidation in the biofilter community, and activity of archaeal ammonia-oxidizing taxa was not detected in the SIP fractions. This study provides the first in situ evidence of ammonia oxidation by comammox Nitrospira in an ecologically relevant complex microbiome.IMPORTANCE With this study we provide the first in situ evidence of ecologically relevant ammonia oxidation by comammox Nitrospira in a complex microbiome and document an unexpectedly high H13CO3- uptake and growth of proteobacterial and acidobacterial taxa under ammonia selectivity. This finding raises the question of whether comammox Nitrospira is an equally important ammonia oxidizer in other environments.


Assuntos
Bactérias/genética , DNA/genética , Água Subterrânea/microbiologia , Nitrificação/genética , RNA Ribossômico 16S/genética , Amônia/metabolismo , Archaea/genética , Processos Autotróficos/genética , Isótopos , Nitratos/metabolismo , Nitritos/metabolismo , Ciclo do Nitrogênio/genética , Oxirredução
16.
Int J Food Microbiol ; 295: 8-18, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30776731

RESUMO

Tonsils in the oral cavity are an important source of contamination during pig slaughter, but have not received as much attention as faecal contamination. In the present study, ten pigs were sampled from tonsils, faeces and three different areas on each carcass. The samples were analysed by both culturing of Escherichia coli and Yersinia enterocolitica and by 16S rRNA gene sequencing to characterize the bacterial communities. Comparing culture data from deep tonsil tissue and tonsil surface showed similar numbers of E. coli but significantly higher numbers of Y. enterocolitica in the deep tissue samples. Microbiota analysis showed similar bacterial communities in the two sample types at phylum level, while comparison at genus level showed significant differences between the relative abundance of several genera in the two sample types. The finding of a significantly higher relative abundance of Yersinia in tonsil tissue compared to tonsil surface supported the culture analysis. The microbiota analysis also investigated characteristics of the bacterial community that could discriminate bacterial transfer from tonsils and faeces to the carcass during slaughter. The microbiota analyses demonstrated that Fusobacteria and Proteobacteria are the most abundant phyla in tonsils, while Firmicutes showed the highest relative abundance in faeces. The dominating phylum on carcasses was Proteobacteria. Besides Proteobacteria, the swabbing area on the forepart of the carcass, showed a higher relative abundance of Firmicutes and Fusobacteria compared to swabbing areas on the rear part and mid-section of the carcass. Principal coordinate analysis showed clear clustering of samples based on sample source (tonsils, faeces and carcass). Carcass swab samples from the forepart tended to cluster closer to the tonsil samples compared to carcass swab samples from the rear part and mid-section. Identification of the genera Fusobacterium, Moraxella, Actinobacillus and non-E. coli genera of the family Enterobacteriaceae in carcass swabs could indicate tonsil contamination, while faecal contamination would more likely include higher prevalence of bacteria belonging to the class of Clostridia. The present study supports that it is possible to identify bacterial groups that are indicative for either tonsil or faecal carcass contamination. The level and composition of Enterobacteriaceae on the carcasses did, however, indicate that other sources of meat contamination than tonsils and faeces may be important, such as the process environment.


Assuntos
Fenômenos Fisiológicos Bacterianos , Microbiologia de Alimentos , Carne/microbiologia , Tonsila Palatina/microbiologia , Matadouros , Animais , Bactérias/genética , Fezes/microbiologia , Microbiota/genética , Prevalência , RNA Ribossômico 16S/genética , Suínos
17.
Bioresour Technol ; 270: 303-310, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30236907

RESUMO

Keratin refers to a group of insoluble and recalcitrant protein materials. Slaughterhouses produce large amount of keratinous byproducts, which are either disposed or poorly valorized through costly thermochemical processes for animal feed formulation. Learning from nature, keratinolytic microbial consortia stand as a cost-efficient and environmental friendly way to valorize this recalcitrant resource. Directed selection was applied to enrich soil-born microbial consortia, using sequential batch cultivations in keratin medium, while measuring enzymes activity and monitoring consortia compositions via 16S rRNA gene amplicon sequencing. A promising microbial consortium KMCG6, featuring mainly members of Bacteroidetes and Proteobacteria, was obtained. It possessed keratinolytic activity with <25% residual substrate remaining, which also displayed a high degradation reproducibility level after long-term cryopreservation. This work represents an advance in the field of α-keratin degradation with potential for practical applications.


Assuntos
Consórcios Microbianos , Bacteroidetes/genética , Biodegradação Ambiental , Consórcios Microbianos/genética , Proteobactérias/genética , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Solo , Microbiologia do Solo
18.
Nat Commun ; 9(1): 704, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29440648

RESUMO

The originally published version of this Article contained an incorrect version of Figure 3 that was introduced following peer review and inadvertently not corrected during the production process. Both versions contain the same set of abundance data, but the incorrect version has the children's asthma status erroneously disconnected from the abundance data, thereby producing the non-representative p values and graphic presentations. These errors have now been rectified, with the correct version of Figure 3 replaced in both the PDF and HTML versions of the Article.

19.
Nat Commun ; 9(1): 141, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29321519

RESUMO

The composition of the human gut microbiome matures within the first years of life. It has been hypothesized that microbial compositions in this period can cause immune dysregulations and potentially cause asthma. Here we show, by associating gut microbial composition from 16S rRNA gene amplicon sequencing during the first year of life with subsequent risk of asthma in 690 participants, that 1-year-old children with an immature microbial composition have an increased risk of asthma at age 5 years. This association is only apparent among children born to asthmatic mothers, suggesting that lacking microbial stimulation during the first year of life can trigger their inherited asthma risk. Conversely, adequate maturation of the gut microbiome in this period may protect these pre-disposed children.


Assuntos
Asma/epidemiologia , Desenvolvimento Infantil , Microbioma Gastrointestinal/genética , RNA Ribossômico 16S/genética , Asma/genética , Asma/microbiologia , Bacteroides/genética , Bifidobacterium/genética , Pré-Escolar , Enterobacteriaceae/genética , Enterococcus/genética , Feminino , Humanos , Lactente , Masculino , Mães , Risco , Staphylococcus/genética , Streptococcus/genética , Veillonella/genética
20.
J Hazard Mater ; 344: 299-307, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29055834

RESUMO

Metal contamination poses serious biotoxicity and bioaccumulation issues, affecting both abiotic conditions and biological activity in ecosystem trophic levels, especially sediments. The MetalEurop foundry released metals directly into the French river "la Deûle" during a century, contaminating sediments with a 30-fold increase compared to upstream unpolluted areas (Férin, Sensée canal). Previous metaproteogenomic work revealed phylogenetically analogous, but functionally different microbial communities between the two locations. However, their potential activity status in situ remains unknown. The present study respectively compares the structures of both total and active fractions of sediment prokaryotic microbiomes by coupling DNA and RNA-based sequencing approaches at the polluted MetalEurop site and its upstream control. We applied the innovative ecological concept of Functional Response Groups (FRGs) to decipher the adaptive tolerance range of the communities through characterization of microbial lifestyles and strategists. The complementing use of DNA and RNA sequencing revealed indications that metals selected for mechanisms such as microbial facilitation via "public-good" providing bacteria, Horizontal Gene Transfer (HGT) and community coalescence, overall resulting in an unexpected higher microbial diversity at the polluted site.


Assuntos
Sedimentos Geológicos/microbiologia , Metais , Microbiologia da Água , Poluentes Químicos da Água , Biodiversidade , DNA Bacteriano/genética , Sedimentos Geológicos/química , Resíduos Industriais , Microbiota , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Rios
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