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1.
Nat Immunol ; 24(12): 2150-2163, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37872316

RESUMO

Severe dengue (SD) is a major cause of morbidity and mortality. To define dengue virus (DENV) target cells and immunological hallmarks of SD progression in children's blood, we integrated two single-cell approaches capturing cellular and viral elements: virus-inclusive single-cell RNA sequencing (viscRNA-Seq 2) and targeted proteomics with secretome analysis and functional assays. Beyond myeloid cells, in natural infection, B cells harbor replicating DENV capable of infecting permissive cells. Alterations in cell type abundance, gene and protein expression and secretion as well as cell-cell communications point towards increased immune cell migration and inflammation in SD progressors. Concurrently, antigen-presenting cells from SD progressors demonstrate intact uptake yet impaired interferon response and antigen processing and presentation signatures, which are partly modulated by DENV. Increased activation, regulation and exhaustion of effector responses and expansion of HLA-DR-expressing adaptive-like NK cells also characterize SD progressors. These findings reveal DENV target cells in human blood and provide insight into SD pathogenesis beyond antibody-mediated enhancement.


Assuntos
Vírus da Dengue , Dengue , Dengue Grave , Criança , Humanos , Linfócitos B , Células Matadoras Naturais
2.
Brief Bioinform ; 25(6)2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39441244

RESUMO

Noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), play crucial roles in gene expression regulation and are significant in disease associations and medical research. Accurate ncRNA-disease association prediction is essential for understanding disease mechanisms and developing treatments. Existing methods often focus on single tasks like lncRNA-disease associations (LDAs), miRNA-disease associations (MDAs), or lncRNA-miRNA interactions (LMIs), and fail to exploit heterogeneous graph characteristics. We propose ACLNDA, an asymmetric graph contrastive learning framework for analyzing heterophilic ncRNA-disease associations. It constructs inter-layer adjacency matrices from the original lncRNA, miRNA, and disease associations, and uses a Top-K intra-layer similarity edges construction approach to form a triple-layer heterogeneous graph. Unlike traditional works, to account for both node attribute features (ncRNA/disease) and node preference features (association), ACLNDA employs an asymmetric yet simple graph contrastive learning framework to maximize one-hop neighborhood context and two-hop similarity, extracting ncRNA-disease features without relying on graph augmentations or homophily assumptions, reducing computational cost while preserving data integrity. Our framework is capable of being applied to a universal range of potential LDA, MDA, and LMI association predictions. Further experimental results demonstrate superior performance to other existing state-of-the-art baseline methods, which shows its potential for providing insights into disease diagnosis and therapeutic target identification. The source code and data of ACLNDA is publicly available at https://github.com/AI4Bread/ACLNDA.


Assuntos
RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Biologia Computacional/métodos , Algoritmos , RNA não Traduzido/genética , MicroRNAs/genética , Aprendizado de Máquina , Software , Predisposição Genética para Doença
3.
Surg Endosc ; 38(9): 4926-4938, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38977502

RESUMO

BACKGROUND: The safety and efficacy of robotic liver resection (RLR) for patients with hepatocellular carcinoma (HCC) have been reported worldwide. However, the exact role of RLR in HCC patients with liver cirrhosis is not sufficiently determined. METHODS: We conducted a retrospective study on consecutive patients with cirrhosis or non-cirrhosis who received RLR for HCC from 2018 to 2023. Data on patients' demographics and perioperative outcomes were collected and analyzed. Propensity score matching (PSM) analysis was performed. Multivariate logistic regression analysis was performed to determine the risk factors of prolonged postoperative length of stay (LOS) and morbidity. RESULTS: Of the 571 patients included, 364 (64%) had cirrhosis. Among the cirrhotic patients, 48 (13%) were classified as Child-Pugh B. After PSM, the cirrhosis and non-cirrhosis group (n = 183) had similar operative time, estimated blood loss, postoperative blood transfusion, LOS, overall morbidity (p > 0.05). In addition, the intraoperative and postoperative outcomes were similar between the two groups in the subgroup analyses of patients with tumor size ≥ 5 cm, major hepatectomy, and high/expert IWATE difficulty grade. However, patients with Child-Pugh B cirrhosis had longer LOS and more overall morbidity than that of Child-Pugh A. Child-Pugh B cirrhosis, ASA score > 2, longer operative time, and multiple tumors were risk factors of prolonged LOS or morbidity in patients with cirrhosis. CONCLUSION: The presence of Child-Pugh A cirrhosis didn't significantly influence the difficulty and perioperative outcomes of RLR for selected patients with HCC. However, even in high-volume center, Child-Pugh B cirrhosis was a risk factor for poor postoperative outcomes.


Assuntos
Carcinoma Hepatocelular , Hepatectomia , Tempo de Internação , Cirrose Hepática , Neoplasias Hepáticas , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Robóticos , Humanos , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Masculino , Feminino , Estudos Retrospectivos , Cirrose Hepática/complicações , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Robóticos/métodos , Hepatectomia/métodos , Hepatectomia/efeitos adversos , Tempo de Internação/estatística & dados numéricos , Idoso , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Duração da Cirurgia , Pontuação de Propensão , Fatores de Risco , Adulto
4.
Mar Drugs ; 22(9)2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39330280

RESUMO

Hyaluronic acid (HA) is a well-known functional marine polysaccharide. The utilization and derivative development of HA are of great interest. Hyaluronan lyase has wide application prospects in the production of HA oligosaccharides and lower molecular weight HA. In this study, a strain of Enterobacter asburiae CGJ001 with high hyaluronan lyase activity was screened from industrial wastewater. This strain exhibited an impressive enzyme activity of 40,576 U/mL after being incubated for 14 h. Whole genome sequencing analysis revealed that E. asburiae CGJ001 contained a cluster of genes involved in HA degradation, transport, and metabolism. A newly identified enzyme responsible for glycosaminoglycan degradation was designated as HylEP0006. A strain of E. coli BL21(DE3)/pET-22b(+)-hylEP0006 was successfully constructed. HylEP0006 exhibited optimal degradation at 40 °C and pH 7.0, showing a high activity of 950,168.3 U/mg. HylEP0006 showed specific activity against HA. The minimum degradation fragment of HylEP0006 was hyaluronan tetrasaccharides, and HylEP0006 could efficiently degrade HA into unsaturated disaccharides (HA2), with HA2 as the final product. These characteristics indicate that HylEP0006 has a potential application prospect for the extraction and utilization of hyaluronic acid.


Assuntos
Enterobacter , Ácido Hialurônico , Polissacarídeo-Liases , Enterobacter/enzimologia , Enterobacter/genética , Ácido Hialurônico/metabolismo , Ácido Hialurônico/biossíntese , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/metabolismo , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Sequenciamento Completo do Genoma
5.
Ecotoxicol Environ Saf ; 286: 117213, 2024 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-39427542

RESUMO

Antibiotic resistance genes (ARGs) are critical emerging pollutants that have attracted considerable attention. Deoxynivalenol (DON) is one of the most prevalent mycotoxins in cereal crops worldwide, arising severe health hazards to both humans and animals. Even if numerous researches argue in favor of a notorious influence of DON on the gut, the effects of dietary DON exposure on the ARG profile in poultry intestine remain obscure. In this study, two separate feeding experiments using Jing Tint 6 laying hens exposed to 4.5 or 9.0 mg/kg DON were performed to explore the impact of dietary DON exposure on the microbial community structure and the profiles of ARGs in the intestine via 16S rDNA sequencing and metagenomics sequencing, respectively. In addition, growth performance and intestinal barrier function were also determined to assess the feasibility of using DON-contaminated feedstuffs inappropriate for pigs' consumption in laying hens. Chronic ingestion of DON at 9.0 mg/kg did not alter zootechnical parameters. However, histomorphological impairments were observed in liver and jejunum. Additionally, metagenomic sequencing revealed that dietary DON exposure at 9.0 mg/kg level dramatically changed the gut microbial structure and shifted the ARG profile. The abundance of tetracycline ARG subtype in the layer cecum was decreased, whereas the abundance of vancomycin ARG subtype was increased upon DON exposure. Co-occurrence network analysis identified that Prevotella was the major ARG host in the intestine of laying hens. In summary, our findings demonstrated that DON-contaminated feedstuffs inappropriate for pigs' consumption should be prudently used in hen production, and shed new light on the interactions between mycotoxins and ARGs in the poultry intestine.

6.
J Environ Manage ; 369: 122339, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39222589

RESUMO

Cultivation of sloping land is a main cause for soil erosion. Conservation practices, such as soil and stone terraces, may reduce the impacts of erosion but their impacts on soil microbial diversity and functioning related to carbon (C) and nutrient metabolisms remain unclear. This study was conducted to evaluate the effects of slope gradients (5°, 8°, 15°, 25°) and conservation practices (cultivated, uncultivated, soil terrace, and stone terrace) on bacterial and fungal diversities, metagenomic and metabolomic functioning associated with basic soil properties. Our results showed that steep slopes at 25° significantly decreased soil pH, silt percentage, and bacterial and fungal abundances, but that soil and stone terraces increased soil organic C (SOC), silt and clay contents, and fungal abundance compared to sloping cultivated lands. In addition, soil and stone terraces increased both bacterial and fungal alpha diversities, and relative abundances of Crenarchaeota, Nitrospirota, and Latescibacterota, but reduced the proportions of Actinobacteriota and Patescibacteria, thus shifting microbial beta diversities, which were significantly associated with increased SOC and silt content. For metagenomics, soil and stone terraces greatly increased the relative abundance of functional genes related to Respiration, Virulence, disease and defense, Stress response, and nitrogen and potassium metabolisms, such as Denitrification and Potassium homeostasis. For soil metabolomics, a total of 22 soil metabolites was enriched by soil and stone terraces, such as Lipids and lipid-like molecules (Arachidonic acid, Gamma-Linolenic acid, and Pentadecanoic acid), and Organoheterocyclic compounds (Adenine, Laudanosine, Methylpyrazine, and Nicotinic acid). To sum up, soil and stone terraces could reduce some of the negative impacts of steep slope cultivation on soil microbial diversity as well as their metagenomic and metabolomic functioning related to C and nutrient metabolism useful for soil health improvement, potentially bolstering the impact of sustainable practices in erosion hotspots around the world.


Assuntos
Carbono , Microbiologia do Solo , Solo , Solo/química , Carbono/metabolismo , Fungos/metabolismo , Bactérias/metabolismo , Nitrogênio/metabolismo
7.
Phys Rev Lett ; 131(5): 050401, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595229

RESUMO

Gauge theory and thermalization are both topics of essential importance for modern quantum science and technology. The recently realized atomic quantum simulator for lattice gauge theories provides a unique opportunity for studying thermalization in gauge theory, in which theoretical studies have shown that quantum thermalization can signal the quantum phase transition. Nevertheless, the experimental study remains a challenge to accurately determine the critical point and controllably explore the thermalization dynamics due to the lack of techniques for locally manipulating and detecting matter and gauge fields. We report an experimental investigation of the quantum criticality in the lattice gauge theory from both equilibrium and nonequilibrium thermalization perspectives, with the help of the single-site addressing and atom-number-resolved detection capabilities. We accurately determine the quantum critical point and observe that the Néel state thermalizes only in the critical regime. This result manifests the interplay between quantum many-body scars, quantum criticality, and symmetry breaking.

8.
J Urban Health ; 100(5): 950-961, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37605103

RESUMO

The COVID-19 pandemic has dramatically altered people's lives in multiple aspects, including grocery shopping behaviors. Yet, the changing trend of grocery shopping frequencies during the COVID-19 and its associations with food deserts remain unclear. We aimed to (1) examine variations of grocery shopping frequencies at county level in the USA during the COVID-19 pandemic from March 2020 to December 2021; (2) investigate associations between grocery shopping frequencies and food deserts during the COVID-19 pandemic; and (3) explore heterogeneity in grocery shopping frequencies-food desert associations across urban and rural areas. The county-level grocery shopping frequencies were derived from a grocery pattern dataset obtained from SafeGraph. We divided the 22-month period into 5 stages and employed the growth curve modeling to estimate the trajectories of grocery shopping frequencies and the associations between grocery shopping frequencies and food deserts in each stage, separately. Results revealed that grocery shopping frequencies experienced a "W-shaped" pattern from March 2020 to December 2021. Counties with the least percent of food deserts had slower decrease in grocery shopping frequencies at the initial stage and recovered more rapidly at later stages. Counties with the highest percent of food deserts were subject to deprivation amplification as a result of the pandemic. We also found differences existed in the grocery shopping frequencies-food desert associations between metropolitan counties and rural counties. Our findings suggest the impacts of COVID-19 on grocery shopping frequencies varied across different time periods, shedding light on designing different strategies to reduce the risk of contagion while shopping inside of grocery stores. Further, our findings highlight an urgent need to help people living in food deserts (especially in rural counties) to procure healthy foods safely during health emergencies like COVID-19 pandemic which disrupt mobility and social behaviors.


Assuntos
COVID-19 , Desertos Alimentares , Humanos , Estados Unidos/epidemiologia , COVID-19/epidemiologia , Pandemias , Abastecimento de Alimentos , Alimentos
9.
J Environ Manage ; 334: 117524, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36801692

RESUMO

The survival pattern of Escherichia coli O157:H7 (E. coli O157:H7) and its regulatory factors in natural environments have been widely studied. However, there is little information about the survival of E. coli O157:H7 in artificial environments, especially in wastewater treatment facilities. In this study, a contamination experiment was performed to explore the survival pattern of E. coli O157:H7 and its central control factors in two constructed wetlands (CWs) under different hydraulic loading rates (HLRs). The results showed that the survival time of E. coli O157:H7 was longer in the CW under the higher HLR. Substrate ammonium nitrogen and available phosphorus were the main factors that influenced the survival of E. coli O157:H7 in CWs. Despite the minimal effect of microbial α-diversity, some keystone taxa, such as Aeromonas, Selenomonas, and Paramecium, governed the survival of E. coli O157:H7. In addition, the prokaryotic community had a more significant impact on the survival of E. coli O157:H7 than the eukaryotic community. The biotic properties had a more substantial direct power on the survival of E. coli O157:H7 than the abiotic factors in CWs. Collectively, this study comprehensively disclosed the survival pattern of E. coli O157:H7 in CWs, which is an essential addition to the environmental behavior of E. coli O157:H7, providing a theoretical basis for the prevention and control of biological contamination in wastewater treatment processes.


Assuntos
Escherichia coli O157 , Microbiota , Áreas Alagadas , Águas Residuárias , Contagem de Colônia Microbiana
10.
J Environ Sci (China) ; 124: 429-439, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182151

RESUMO

Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes. Existing studies have primarily focused on bacterial responses to antibiotic pollution, but they ignored the microeukaryotic counterpart, though microeukaryotes are functionally important (e.g., predators and saprophytes) in microbial ecology. Herein, we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet (control) and across the outlet sites along a shrimp wastewater discharge channel. The structures of sediment microeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions, which were primarily controlled by the direct effects of phosphate and ammonium (-0.645 and 0.507, respectively). In addition, tetracyclines exerted a large effect (0.209), including direct effect (0.326) and indirect effect (-0.117), on the microeukaryotic assembly. On the contrary, the fungal subcommunity was relatively resistant to antibiotic pollution. Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient, as supported by the significant tipping points. We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes, which can quantitatively and accurately predict (98.7% accuracy) the in-situ antibiotic concentration. Sediment microeukaryotic (except fungal) community is sensitive to antibiotic pollution, and the identified bioindicators could be used for antibiotic pollution diagnosis.


Assuntos
Compostos de Amônio , Antibacterianos , Biomarcadores Ambientais , Fosfatos , Tetraciclinas , Águas Residuárias
11.
PLoS Biol ; 17(4): e3000219, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30973873

RESUMO

Macroautophagy (hereafter autophagy) is a well-conserved cellular process through which cytoplasmic components are delivered to the vacuole/lysosome for degradation and recycling. Studies have revealed the molecular mechanism of transcriptional regulation of autophagy-related (ATG) genes upon nutrient deprivation. However, little is known about their translational regulation. Here, we found that Dhh1, a DExD/H-box RNA helicase, is required for efficient translation of Atg1 and Atg13, two proteins essential for autophagy induction. Dhh1 directly associates with ATG1 and ATG13 mRNAs under nitrogen-starvation conditions. The structured regions shortly after the start codons of the two ATG mRNAs are necessary for their translational regulation by Dhh1. Both the RNA-binding ability and helicase activity of Dhh1 are indispensable to promote Atg1 translation and autophagy. Moreover, eukaryotic translation initiation factor 4E (EIF4E)-associated protein 1 (Eap1), a target of rapamycin (TOR)-regulated EIF4E binding protein, physically interacts with Dhh1 after nitrogen starvation and facilitates the translation of Atg1 and Atg13. These results suggest a model for how some ATG genes bypass the general translational suppression that occurs during nitrogen starvation to maintain a proper level of autophagy.


Assuntos
RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Nitrogênio/deficiência , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia/fisiologia , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Células HEK293 , Humanos , Nitrogênio/metabolismo , Fosforilação , Ligação Proteica , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo
12.
Microb Ecol ; 84(3): 746-758, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34665286

RESUMO

Diatom blooms can significantly affect the succession of microbial communities, yet little is known about the assembly processes and interactions of microbial communities during autumn bloom events. In this study, we investigated the ecological effects of an autumn diatom bloom on prokaryotic communities (PCCs) and microeukaryotic communities (MECs), focusing on their assembly processes and interactions. The PCCs were largely dominated by Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, and Flavobacteria, while the MECs primarily included Diatomea, Dinoflagellata, and Chlorophyta. The succession of both PCCs and MECs was mainly driven by this diatom bloom and environmental factors, such as nitrate and silicate. Null modeling revealed that homogeneous selection had a more pronounced impact on the structure of PCCs compared with that of MECs. In particular, drift and dispersal limitation cannot be neglected in the assembly processes of MECs. Co-occurrence network analyses showed that Litorimicrobium, Cercozoa, Marine Group I (MGI), Cryptomonadales, Myrionecta, and Micromonas may affect the bloom process. In summary, these results elucidated the complex, robust interactions and obviously distinct assembly mechanisms of PCCs and MECs during a diatom bloom and extend our current comprehension of the ecological mechanisms and microbial interactions involved in an autumn diatom bloom process.


Assuntos
Alphaproteobacteria , Diatomáceas , Dinoflagellida , Gammaproteobacteria , Baías/microbiologia
13.
J Gastroenterol Hepatol ; 36(2): 302-310, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32652685

RESUMO

BACKGROUND AND AIM: An increasing number of transarterial chemoembolization (TACE) plus sorafenib combination therapy has been applied for unresectable hepatocellular carcinoma (HCC). However, it remains controversial whether combination therapy is superior to sorafenib monotherapy. Therefore, we aimed to perform a meta-analysis to evaluate the efficacy and safety of the combination therapy of TACE plus sorafenib for unresectable HCC. METHODS: This meta-analysis was based on the relative outcomes from a specific search of online databases between January 2008 and November 2019, and subgroup analyses were conducted to identify potential predictive factors. RESULTS: A total of 3868 patients (TACE plus sorafenib vs sorafenib, 1181 vs 2687) were identified from nine studies, including one randomized controlled trial and eight retrospective cohort studies. The pooled results revealed that TACE plus sorafenib combination therapy significantly improves overall survival with the combined hazard ratio 0.74 (95% confidence interval [CI] = 0.66-0.84, P < 0.001), time to progression (hazard ratio = 0.73, 95%CI = 0.65-0.82, P < 0.001), and objective response rate (odds ratio = 2.19, 95% CI = 1.31-3.66, P = 0.003). Subgroup analysis indicated that patients who developed macrovascular invasion achieve significantly great overall survival (P for interaction = 0.001) with combination therapy, in contrast to nonmacrovascular invasion patients. In addition, no significant differences in adverse events were observed. CONCLUSION: This meta-analysis demonstrated that TACE plus sorafenib combination therapy is superior to sorafenib monotherapy and should be recommended as an optimal treatment choice for unresectable HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Quimioembolização Terapêutica/métodos , Quimioterapia Adjuvante/métodos , Neoplasias Hepáticas/terapia , Sorafenibe/administração & dosagem , Carcinoma Hepatocelular/mortalidade , Terapia Combinada , Humanos , Neoplasias Hepáticas/mortalidade , Segurança , Taxa de Sobrevida , Resultado do Tratamento
14.
Appl Environ Microbiol ; 86(13)2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32358000

RESUMO

Understanding how species interaction and assembly processes structure the abundant and rare bacterial biospheres in soils is crucial for predicting how biodiversity influences ecosystem functioning. Here, we profiled the bacterial communities across a salt marsh ecosystem gradient to investigate the co-occurrence patterns across taxa and the relative influence of ecological processes mediating the assembly of the abundant and rare biospheres in soil. Our results revealed abundant taxa to be ubiquitous across all sites, whereas the distributions of the rare taxa were relatively more site specific. The α-diversity indices and ß-diversity of rare subcommunities were significantly higher than those of the abundant subcommunities. Besides, both the taxonomic and functional composition of soil bacterial communities differed significantly between the two biospheres. Furthermore, the influence of stochasticity differed in each subcommunity. In particular, stochastic processes were relatively more important in constraining the assembly of rare taxa. Co-occurrence network analysis revealed that a few abundant taxa occupy central nodes within the networks, possibly indicating crucial roles as keystone taxa. Collectively, these findings suggest that abundant and rare bacterial biospheres have distinct distributions underpinned by a dynamic interplay of ecological processes and taxon co-occurrence patterns.IMPORTANCE Estuarine salt marshes are highly productive ecosystems subjected to regular disturbances by hydrodynamic exchange. However, little is known about how distinct assembly processes and co-occurrence of taxa influence the structure of the abundant and rare bacterial biospheres in these soil systems. This study aims at unravelling these intricacies by studying a typical estuarine salt marsh located in Hangzhou Bay, China. Our study provides important pieces of evidence on the diverse distribution of rare and abundant bacterial biospheres. We show that a few abundant taxa are central nodes in species co-occurrence, potentially playing important roles as keystone species in the system. In addition, we highlight a dynamic interplay of assembly processes structuring these two subcommunities.


Assuntos
Bactérias/isolamento & purificação , Microbiota , Microbiologia do Solo , Áreas Alagadas , Bactérias/classificação , China , Estuários , Sedimentos Geológicos/microbiologia
15.
Appl Environ Microbiol ; 85(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30635381

RESUMO

Bacterial communities play essential roles in estuarine marsh ecosystems, but the interplay of ecological processes underlying their community assembly is poorly understood. Here, we studied the sediment bacterial communities along a linear gradient extending from the water-land junction toward a high marsh, using 16S rRNA gene amplicon sequencing. Bacterial community compositions differed significantly between sediment transects. Physicochemical properties, particularly sediment nutrient levels (i.e., total nitrogen [TN] and available phosphorus [AP]), as well as sediment physical structure and pH (P < 0.05), were strongly associated with the overall community variations. In addition, the topological properties of bacterial cooccurrence networks varied with distance to the water-land junction. Both node- and network-level topological features revealed that the bacterial network of sediments farthest from the junction was less intense in complexity and interactions than other sediments. Phylogenetic null modeling analysis showed a progressive transition from stochastic to deterministic community assembly for the water-land junction sites toward the emerging terrestrial system. Taken together, data from this study provide a detailed outline of the distribution pattern of the sediment bacterial community across an estuarine marsh and inform the mechanisms and processes mediating bacterial community assembly in marsh soils.IMPORTANCE Salt marshes represent highly dynamic ecosystems where the atmosphere, continents, and the ocean interact. The bacterial distribution in this ecosystem is of great ecological concern, as it provides essential functions acting on ecosystem services. However, ecological processes mediating bacterial assembly are poorly understood for salt marshes, especially the ones located in estuaries. In this study, the distribution and assembly of bacterial communities in an estuarine marsh located in south Hangzhou Bay were investigated. The results revealed an intricate interplay between stochastic and deterministic processes mediating the assembly of bacterial communities in the studied gradient system. Collectively, our findings illustrate the main drivers of community assembly, taking into consideration changes in sediment abiotic variables and potential biotic interactions. Thus, we offer new insights into estuarine bacterial communities and illustrate the interplay of ecological processes shaping the assembly of bacterial communities in estuarine marsh ecosystems.


Assuntos
Bactérias/isolamento & purificação , Microbiota , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Ecossistema , Estuários , Sedimentos Geológicos/microbiologia , Nitrogênio/metabolismo , Fósforo/metabolismo , Filogenia , Áreas Alagadas
16.
Biomacromolecules ; 20(8): 2942-2952, 2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31276401

RESUMO

The identification and use of antibodies dominate the biologic, clinical diagnostic, and therapeutic landscapes. In particular, antibodies have become essential tools in a variety of protein analytical experiments and to study the disposition of biologic therapeutics. One emerging class of peptide biologics is known as the elastin-like polypeptides (ELPs), which are repetitive protein polymers inspired by human tropoelastin. A major limitation in the clinical translation of ELP biologics has been a lack of a monoclonal antibody (mAb) to characterize their identity during expression. To facilitate these studies, we successfully generated a new mAb that is specific toward ELPs and ELP fusion proteins. A purified antibody was evaluated in an ELISA, western blotting, and immunofluorescence assay. The optimal anti-ELP mAb proved to be highly reactive and specific toward ELPs. Moreover, they were able to detect ELPs with a variety of aliphatic guest residues. ELPs phase-separate in response to heating; furthermore, when incubated at a great excess of ELPs, the anti-ELP mAb partially blocks phase separation. These findings are direct evidence that novel murine mAbs can be raised against purified ELPs. This new reagent will enable purification, experimental detection, and characterization of these biopolymers.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/biossíntese , Formação de Anticorpos , Biopolímeros/química , Elastina/imunologia , Mieloma Múltiplo/metabolismo , Peptídeos/imunologia , Animais , Feminino , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia
17.
BMC Genomics ; 17: 405, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27411304

RESUMO

BACKGROUND: The rapid spread of Clostridium difficile NAP1/BI/027 (C. difficile 027) has become one of the leading threats of healthcare-associated infections worldwide. However, C. difficile 027 infections have been rarely reported in Asia, particularly in China. RESULTS: In this study, we identified a rare C. difficile bloodstream infection (BSI) from three isolates of a patient during repeated hospital admission. This finding triggered a retrospective epidemiological study to scan all cases and strains emerged from this ward during the past three years. Using medical personnel interviews, medical record reviews and the genomic epidemiology, two outbreaks in 2012 and 2013-2014 were identified. Through using whole genome sequencing, we succeeded to trace the origin of the BSI strain. Surprisingly, we found the genome sequences were similar to C. difficile 027 strain R20291, indicating the occurrence of a rare C. difficile 027 strain in China. Integrated epidemiological investigation and whole genome sequencing of all strains, we constructed a nosocomial transmission map of these two C. difficile 027 outbreaks and traced the origin of the infection. CONCLUSIONS: By genome sequencing, spatio-temporal analysis and field epidemiology investigation, we can estimate their complex transform network and reveal the possible modes of transmission in this ward. Based on their genetic diversity, we can assume that the toilets, bathroom, and janitor's equipment room may be contaminated area, which may be suggested to improve infection control measures in the following health care.


Assuntos
Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecção Hospitalar , Enterocolite Pseudomembranosa/microbiologia , Enterocolite Pseudomembranosa/transmissão , Genoma Bacteriano , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Análise por Conglomerados , Biologia Computacional/métodos , Surtos de Doenças , Enterocolite Pseudomembranosa/epidemiologia , Feminino , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Tipagem Molecular , Filogenia , Estudos Retrospectivos
18.
BMC Infect Dis ; 16: 161, 2016 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-27091177

RESUMO

BACKGROUND: This study aimed to investigate the prevalence of healthcare-associated infection (HAI) in the China-Japan Friendship Hospital, a tertiary level hospital in Beijing, China. METHODS: We defined HAI using the criteria established by the Ministry of Health of the People's Republic of China. Three cross-sectional surveys were conducted from 2012 to 2014. Inpatients who had been hospitalized for at least 48 h were surveyed. Information on HAI prevalence, isolated pathogens and use of antibiotics were collected. Logistic regression models were used to assess the associations between HAI and potential risk factors. RESULTS: During three cross-sectional surveys, a total number of 4,029 patients were included (1,233 patients in 2012, 1,220 patients in 2013 and 1,576 patients in 2014). The overall prevalence of patients with HAI was 3.6 % (95 % confidence interval (CI) 3.1 %-4.2 %). Respiratory tract infections were the most common type (64.7 %) of HAIs, followed by urinary tract infections (12.6 %) and bloodstream infections (5.4 %). HAI occurrences were significantly associated with male sex (odds ratio (OR) = 2.25, 95 % CI 1.53-3.32), age over 85 years (OR = 4.74, 95 % CI 2.54-8.83), hospitalization in the intensive care units (ICUs) (OR = 2.42, 95 % CI 1.31-4.49), indwelling urinary catheter (OR = 4.21, 95 % CI 2.46-7.20) and mechanical ventilation (OR = 2.31, 95 % CI 1.30-4.09). Gram-negative bacteria were found to be the most isolated pathogens (67.1 %), with gram-positive bacteria and fungi accounted for 20.3 % and 10.5 %, respectively. Antibiotics were administered to 34.3 % of the included patients over the study period. CONCLUSIONS: The overall HAI prevalence in our hospital is similar to previous studies that were conducted in other areas of China, and the respiratory tract infection should be the priority in HAI reduction control within China. We should focus HAI reduction efforts on patients with advanced age, hospitalization in the ICU and indwelling devices.


Assuntos
Infecção Hospitalar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , China/epidemiologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Estudos Transversais , Feminino , Fungos/isolamento & purificação , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Unidades de Terapia Intensiva , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Infecções Respiratórias/epidemiologia , Fatores de Risco , Fatores Sexuais , Inquéritos e Questionários , Centros de Atenção Terciária , Infecções Urinárias/epidemiologia , Adulto Jovem
19.
Appl Environ Microbiol ; 80(1): 70-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24123745

RESUMO

The survival of Escherichia coli O157:H7 in soils can contaminate vegetables, fruits, drinking water, etc. However, data on the impact of E. coli O157:H7 on soil microbial communities are limited. In this study, we monitored the changes in the indigenous microbial community by using the phospholipid fatty acid (PLFA) method to investigate the interaction of the soil microbial community with E. coli O157:H7 in soils. Simple correlation analysis showed that the survival of E. coli O157:H7 in the test soils was negatively correlated with the ratio of Gram-negative (G(-)) to Gram-positive (G(+)) bacterial PLFAs (G(-)/G(+) ratio). In particular, levels of 14 PLFAs were negatively correlated with the survival time of E. coli O157:H7. The contents of actinomycetous and fungal PLFAs in the test soils declined significantly (P, <0.05) after 25 days of incubation with E. coli O157:H7. The G(-)/G(+) ratio declined slightly, while the ratio of bacterial to fungal PLFAs (B/F ratio) and the ratio of normal saturated PLFAs to monounsaturated PLFAs (S/M ratio) increased, after E. coli O157:H7 inoculation. Principal component analysis results further indicated that invasion by E. coli O157:H7 had some effects on the soil microbial community. Our data revealed that the toxicity of E. coli O157:H7 presents not only in its pathogenicity but also in its effect on soil microecology. Hence, close attention should be paid to the survival of E. coli O157:H7 and its potential for contaminating soils.


Assuntos
Biota , Escherichia coli O157/crescimento & desenvolvimento , Interações Microbianas , Microbiologia do Solo , Verduras/microbiologia , Ácidos Graxos/análise , Viabilidade Microbiana , Fosfolipídeos/análise , Solo/química
20.
Phys Rev Lett ; 112(22): 225301, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24949775

RESUMO

Recent experimental and numerical studies of the critical-temperature exponent ϕ for the superfluid-Bose-glass universality in three-dimensional systems report strong violations of the key quantum critical relation, ϕ=νz, where z and ν are the dynamic and correlation-length exponents, respectively; these studies question the conventional scaling laws for this quantum critical point. Using Monte Carlo simulations of the disordered Bose-Hubbard model, we demonstrate that previous work on the superfluid-to-normal-fluid transition-temperature dependence on the chemical potential (or the magnetic field, in spin systems), T_{c}∝(µ-µ_{c})^{ϕ}, was misinterpreting transient behavior on approach to the fluctuation region with the genuine critical law. When the model parameters are modified to have a broad quantum critical region, simulations of both quantum and classical models reveal that the ϕ=νz law [with ϕ=2.7(2), z=3, and ν=0.88(5)] holds true, resolving the ϕ-exponent "crisis."

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