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Ammonia-oxidizing bacteria (AOB) are ubiquitous on the earth and have broad applications in bioremediation. However, the number of their species with standing in nomenclature and deposited in Microbial Culture Collections still remains low. Moreover, only a few novel species have been reported over the last decades. In this study, we sealed agar in serum bottles to develop a kind of solid agar plate with the oxygen concentration in the headspace maintained at low levels. By using these plates, eight AOB isolates including two novel species were obtained. When AOB cells were grown on the sealed solid agar plates, the time to form visible colonies was largely reduced and the maximum diameter of colonies reached 2 mm, which makes the process of AOB isolation rapid and efficient. Based on five AOB isolates, the headspace oxygen concentration had a significant influence on AOB growth either on solid plate or in liquid culture. Especially, when grown under 21 % O2, the number of colonies formed on solid agar plates was very low and sometimes no visible colony formed. Besides the application on AOB isolation, the sealed solid agar plate was also effective for the enumeration and preservation of AOB cells. When preserved under room temperature for more than ten months, the AOB colonies on the plate could still be recovered. This method provides a feasible way to isolate more novel AOB species from the environment and deposit more species in Microbial Culture Collections.
Assuntos
Ágar , Amônia , Bactérias , Oxirredução , Amônia/metabolismo , Bactérias/metabolismo , Oxigênio/metabolismo , Meios de Cultura , Crescimento QuimioautotróficoRESUMO
Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. Identification of new and elite Pst-resistance loci or genes has the potential to enhance overall resistance to this pathogen. Here, we conducted an integrated genome-wide association study (GWAS) and transcriptomic analysis to screen for loci associated with resistance to stripe rust in 335 accessions from Yunnan, including 311 landraces and 24 cultivars. Based on the environmental phenotype, we identified 113 protein kinases significantly associated with Pst resistance using mixed linear model (MLM) and generalized linear model (GLM) models. Transcriptomic analysis revealed that 52 of 113 protein kinases identified by GWAS were up and down regulated in response to Pst infection. Among these genes, a total of 15 receptor kinase genes were identified associated with Pst resistance. 11 candidate genes were newly discovered in Yunnan wheat germplasm. Our results revealed that resistance alleles to stripe rust were accumulated in Yunnan wheat germplasm, implying direct or indirect selection for improving stripe rust resistance in elite wheat breeding programs.
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Resistência à Doença , Estudo de Associação Genômica Ampla , Doenças das Plantas , Puccinia , Triticum , Triticum/genética , Triticum/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Resistência à Doença/genética , China , Puccinia/fisiologia , Perfilação da Expressão Gênica , Basidiomycota/fisiologia , Genes de Plantas , Proteínas Quinases/genética , Transcriptoma , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
The transformation of toxic arsine (AsH3) gas into valuable elemental arsenic (As0) from industrial exhaust gases is important for achieving sustainable development goals. Although advanced arsenic removal catalysts can improve the removal efficiency of AsH3, toxic arsenic oxides generated during this process have not received adequate attention. In light of this, a novel approach for obtaining stable As0 products was proposed by performing controlled moderate oxidation. We designed a tailored Ni-based catalyst through an acid etching approach to alter interactions between Ni and NaY. As a result, the 1Ni/NaY-H catalyst yielded an unprecedented proportion of As0 as the major product (65%), which is superior to those of other reported catalysts that only produced arsenic oxides. Density functional theory calculations clarified that Ni species changed the electronic structure of oxygen atoms, and the formed [NiIII-OH (µ-O)] active centers facilitated the adsorption of AsH2*, AsH*, and As* reaction intermediates for As-H bond cleavage, thereby decreasing the direct reactivity of oxygen with the arsenic intermediates. This work presents pioneering insights into inhibiting excessive oxidation during AsH3 removal, demonstrating potential environmental applications for recovery of As0 from toxic AsH3.
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Arsênio , Zeolitas , Níquel/química , Elétrons , Oxigênio , GasesRESUMO
The application of urea in agricultural soil significantly boosts nitrous oxide (N2O) emissions. However, the reason for nitrite accumulation, the period of nitrite-oxidizing bacteria (NOB) suppression, and the main NOB species for nitrite removal behind urea fertilization have not been thoroughly investigated. In this study, four laboratory microcosm experiments were conducted to simulate urea fertilization in agricultural soils. We found that within 36 h of urea application, nitrite oxidation lagged behind ammonia oxidation, leading to nitrite accumulation and increased N2O emissions. However, after 36 h, NOB activity recovered and then removed nitrite, leading to reduced N2O emissions. Urea use resulted in an N2O emission rate tenfold higher than ammonium. During incubation, Nitrobacter-affiliated NOB growth decreased initially but increased later with urea use, while Nitrospira-affiliated NOB appeared unaffected. Chlorate suppression of NOB lasted longer, increasing N2O emissions. Urease inhibitors effectively reduced N2O emissions by slowing urea hydrolysis and limiting free ammonia production, preventing short-term NOB suppression. In summary, short-term NOB suppression during urea hydrolysis played a crucial role in increasing N2O emissions from agricultural soils. These findings revealed the reasons behind the surge in N2O emissions caused by extensive urea application and provided guidance for reducing N2O emissions in agricultural production processes.
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Cisplatin-based chemotherapy is often used in advanced gastric cancer (GC) treatment, yet resistance to cisplatin may lead to treatment failure. Mechanisms underlying cisplatin resistance remain unclear. Recent evidence highlighted the role of macrophages in cancer chemoresistance. Macrophage-derived exosomes were shown to facilitate intercellular communication. Here, we investigated the cisplatin resistance mechanism based on macrophage-derived exosomes in gastric cancer. Cell growth and apoptosis detection experiments revealed that M2-polarized macrophages increased the resistance of GC cells to cisplatin. qRT-PCR, RNAase R assay, actinomycin D assay and cell nucleo-cytoplasmic separation experiments confirmed the existence of circTEX2 in macrophage cytoplasm, with a higher expression level in M2 macrophages than that in M1 macrophages. Further experiments showed that circTEX2 acted as microRNA sponges for miR-145 and regulated the expression of ATP Binding Cassette Subfamily C Member 1 (ABCC1). Inhibition of the circTEX2/miR-145/ABCC1 axis blocked the cisplatin resistance of gastric cancer induced by M2 macrophages, as evidenced by in vitro and in vivo experiments. In conclusion, our research suggests that the exosomal transfer of M2 macrophage-derived circTEX2 enhances cisplatin resistance in gastric cancer through miR-145/ABCC1. Additionally, communication between macrophages and cancer cells via exosomes may be a promising therapeutic target for the treatment of cisplatin-resistant gastric cancer.
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Cisplatino , Resistencia a Medicamentos Antineoplásicos , Exossomos , Regulação Neoplásica da Expressão Gênica , Macrófagos , MicroRNAs , Proteínas Associadas à Resistência a Múltiplos Medicamentos , RNA Circular , Neoplasias Gástricas , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , MicroRNAs/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Animais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , RNA Circular/genética , Exossomos/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Camundongos , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Antineoplásicos/farmacologia , Camundongos NusRESUMO
A sulphur-oxidizing and nitrogen-fixing bacterium, designated strain LS2T, was isolated from freshwater collected from the Pearl River in Guangzhou, PR China. The strain was an obligate chemolithoautotroph, utilizing reduced sulphur compounds (sulphide, sulphite, elemental sulphur, thiosulphate and tetrathionate) as energy sources and electron donors. Diazotrophic growth of strain LS2T was observed at 15-40â°C, pH 5-9, with a NaCl concentration range of 0-0.68 mol l-1 and with oxygen content higher than 21â%. The major cellular fatty acids were summed feature 8 (comprising C18â:â1 ω7c and/or C18â:â1 ω6c) and C16â:â0. The DNA G+C content of the complete genome sequence was 60.7 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain LS2T formed a lineage within the family Halothiobacillaceae, showing gene sequence identity of 96.8â% with its closest relative Halothiobacillus neapolitanus c2. The genome of strain LS2T contains multiple genes encoding sulphur-oxidizing enzymes that catalyse the oxidation of reduced sulphur compounds and an nif complex encoding enzymes for nitrogen fixation. In addition, the genome contains genes encoding cbb3-type cytochrome c oxidase, aa3-type cytochrome c oxidase, bd-type quinol oxidase and cytochrome o oxidase, which enable the survival strain LS2T under oxic and microaerophilic conditions. On the basis of phenotypic, genotypic and phylogenetic data, strain LS2T is considered to represent a novel species of the genus Halothiobacillus, for which the name Halothiobacillus diazotrophicus sp. nov. is proposed. The type strain is LS2T (=GDMCC 1.4095T=JCM 39442T).
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Ácidos Graxos , Halothiobacillus , Ácidos Graxos/química , Halothiobacillus/genética , Halothiobacillus/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filogenia , RNA Ribossômico 16S/genética , Composição de Bases , DNA Bacteriano/genética , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , Enxofre/metabolismo , Rios/microbiologia , Compostos de Enxofre , Oxirredução , Nitrogênio , Fosfolipídeos/químicaRESUMO
Alpha-glucosidase (α-Glu) plays a crucial role in regulating the normal physiological function of the body; therefore, α-Glu activity detection is crucial in clinical studies. In this study, a nickel-based metal-organic framework (Ni-MOF) co-doped with sulfur dots (SDs) and iron (Fe) was designed and constructed for the colorimetric detection of α-Glu. The SDs/Fe/Ni-MOF shows a very low Michaelis-Menten constant (0.0466 mM) for H2O2, suggesting a very high affinity for H2O2. Additionally, the free radicals generated by the nanozyme-catalyzed reaction were analyzed, and the feasibility of the nanozyme-catalyzed process was further verified using density functional theory. The bimetallic (Fe and Ni) can improve the catalytic activity of the material, and sulfur can improve the affinity with the substrate to further enhance the catalytic performance. Notably, hydroquinone (HQ) inhibits nanozyme activity, whereas α-Glu hydrolyzes alpha-arbutin (α-Arb) and subsequently produces HQ. Therefore, this study developed a method for detecting α-Glu activity using α-Arb as a substrate. This method has high selectivity, a wide detection range (1.00-100 U L-1), and a low detection limit (0.525 U L-1). Finally, the method was used to α-Glu activity detected in serum samples with good accuracy. This study provides a new method for the detection of α-Glu.
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Peróxido de Hidrogênio , Estruturas Metalorgânicas , alfa-Glucosidases , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Colorimetria/métodos , Ferro , Níquel , Enxofre/química , Nanopartículas/químicaRESUMO
Cisplatin is the first-line drug for gastric cancer (GC). Cisplatin resistance is the most important cause of poor prognosis for GC. Increasing evidence has identified the important role of macrophage polarization in chemoresistance. CircRNAs are newly discovered non-coding RNAs, characterized by covalently closed loops with high stability. Previous studies have reported a significant difference between circRNA profiles expressed in classically activated M1 macrophages, and those expressed in alternatively activated M2 macrophages. However, the underlying mechanism behind the regulation of GC cisplatin resistance by macrophages remains unclear. In our study, we observed the aberrant high expression of circSOD2 in M1 macrophages derived from THP-1. These expression patterns were confirmed in macrophages from patients with GC. Detection of the M1 and M2 markers confirmed that overexpression of circSOD2 enhances M1 polarization. The viability of cisplatin-treated GC cells was significantly reduced in the presence of macrophages overexpressing circSOD2, and cisplatin-induced apoptosis increased dramatically. In vivo experiments showed that macrophages expressing circSOD2 enhanced the effect of cisplatin. Moreover, we demonstrated that circSOD2 acts as a microRNA sponge for miR-1296 and regulates the expression of its target gene STAT1 (signal transducer and activator of transcription 1). CircSOD2 exerts its function through the miR-1296/STAT1 axis. Inhibition of circSOD2/miR-1296/STAT1 may therefore reduce M1 polarization. Overexpression of circSOD2 promotes the polarization of M1 macrophages and enhances the effect of cisplatin in GC. CircSOD2 is a novel positive regulator of M1 macrophages and may serve as a potential target for GC chemotherapy.
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MicroRNAs , Neoplasias Gástricas , Humanos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Macrófagos/metabolismo , MicroRNAs/metabolismo , Fenótipo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMO
Ammonia-oxidizing bacteria (AOB) play an important role in the global nitrogen cycle and have broad applications in the nitrogen removal from wastewater. However, the AOB species are sensitive to environmental factors and usually form tight relationships with other microbes, making the AOB isolation and maintenance are difficult and time-consuming. In this study, the relationship that occurred between AOB and their bacterial partners was found to be able to improve the ammonia oxidation; during the co-cultivation, the magnesium ions (Mg2+) with removal rate as high as 36.7% was removed from culture medium by the concomitant bacterial species, which was regarded as the main reason for improving ammonia oxidation. During the pure cultivation of AOB isolate, when the concentration of Mg2+ reduced to low levels, the ammonia-oxidizing activity was more than 5 times and the amoA gene expression was more than 12 times higher than that grown in the initial culture medium. Based on a newly designed culture medium, the ammonia oxidation of AOB isolate grown in liquid culture was significantly promoted and the visible AOB colonies with much more number and larger diameter were observed to form on agar plates. With the addition of high concentration of calcium carbonate (CaCO3), AOB colonies could be easily and specifically identified by following the hydrolytic zones that formed around AOB colonies. Another AOB isolates were successively obtained from different samples and within a short time, suggesting the feasibility and effectivity of this culture medium and strategy on the AOB isolation from environments.
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Amônia , Betaproteobacteria , Amônia/metabolismo , Archaea , Bactérias/metabolismo , Betaproteobacteria/metabolismo , Íons/metabolismo , Magnésio , Oxirredução , FilogeniaRESUMO
Hebei Province, located in the North China Plain (NCP) and encircling Beijing and Tianjin, has been suffering from severe air pollution. The monthly average fine particulate matter (PM2.5) concentration was up to 276 µg/m3 in Hebei Province, which adversely affects human health. However, few studies evaluated the coordinated health impact of exposure to PM (PM2.5 and PM10) and other key air pollutants (SO2, NO2, CO, and surface ozone (O3)). In this study, we systematically analyzed the health risks (both mortality and morbidity) due to multiple air pollutants exposures in Hebei Province. The economic loss associated with these health consequences was estimated using the value of statistical life (VSL) and cost of illness (COI) methods. Our results show the health burden and economic loss attributable to multiple ambient air pollutants exposures in Hebei Province is substantial. In 2017, the total premature mortality from multiple air pollutants exposures in Hebei Province was 69,833 (95% CI: 55,549-83,028), which was 2.9 times higher than that of the Pearl River Delta region (PRD). Most of the potential economic loss (79.65%) was attributable to premature mortality from air pollution. The total economic loss due to the health consequences of multiple air pollutants exposures was 175.16 (95% CI: 134.61-224.61) billion Chinese Yuan (CNY), which was 4.92% of Hebei Province's annual gross domestic product (GDP). Thus, the adverse health effects and economic loss caused by exposure to multiple air pollutants should be seriously taken into consideration. To alleviate these damages, Hebei's government ought to establish more stringent measures and regulations to better control air pollution.
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Poluentes Atmosféricos , Poluição do Ar , Material Particulado , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , Poluição do Ar/estatística & dados numéricos , China/epidemiologia , Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais , Humanos , Material Particulado/análise , Material Particulado/toxicidadeRESUMO
Colorectal cancer (CRC) is the third main cause of cancer-relevant deaths worldwide, and its incidence has increased in recent decades. Previous studies have indicated that certain long noncoding RNAs (lncRNAs) have regulatory roles in tumor occurrence and progression. Often, lncRNAs are competitive endogenous RNAs that sponge microRNAs to up-regulate mRNAs. Here, we examined the role of a novel lncRNA gamma-butyrobetaine hydroxylase 1 antisense RNA 1 (BBOX1-AS1) in CRC. We observed that BBOX1-AS1 is overexpressed in CRC cell lines, and BBOX1-AS1 knockdown enhances cell proliferation, migration and invasion while reducing cell apoptosis. miR-361-3p is present at a low level in CRC and is negatively modified by BBOX1-AS1. Moreover, miR-361-3p was validated to be targeted by BBOX1-AS1. Src homology 2 B adaptor protein 1 (SH2B1) was notably upregulated in CRC cell lines and was identified as a downstream gene of miR-361-3p. In addition, we found that miR-361-3p amplification can suppress the expression of SH2B1. Finally, data from rescue assays suggested that overexpression of SH2B1 counteracted BBOX1-AS1 silencing-mediated inhibition of CRC progression. In conclusion, BBOX1-AS1 promotes CRC progression by sponging hsa-miR-361-3p and up-regulating SH2B1.
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Neoplasias Colorretais , MicroRNAs , RNA Longo não Codificante , Proteínas Adaptadoras de Transdução de Sinal/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , gama-Butirobetaína DioxigenaseRESUMO
Gastric cancer is a common lethal malignancy and causes great cancer-related mortality worldwide. MicroRNA (miR)-328-3p is implicated in the progression of various human cancers; however, its role and mechanism in the progression of gastric cancer remain unclear.Human gastric cancer cells were incubated with miR-328-3p mimic, inhibitor or the matched negative control. Cell viability, colony formation, migrative and invasive capacity, cell apoptosis and oxidative stress were measured. To clarify the involvement of nuclear factor-E2-related factor 2 (NRF2) and kelch-like ECH-associated protein 1 (KEAP1), small interfering RNA was used. miR-328-3p was upregulated in human gastric cancer cells and tissues, and its level positively correlated with the progression of gastric cancer. miR-328-3p promoted cell viability, colony formation, migration and invasion, thereby facilitating the progression of gastric cancer. miR-328-3p mimic reduced, while miR-328-3p inhibitor increased apoptosis and oxidative stress of human gastric cancer cells. Mechanistically, miR-328-3p upregulated NRF2 via targeting KEAP1to attenuate excessive free radical production and cell apoptosis. miR-328-3p functions as an oncogenic gene and inhibiting miR-328-3p may help to develop novel therapeutic strategies of human gastric cancer.
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Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , MicroRNAs/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Neoplasias Gástricas/metabolismo , Progressão da Doença , Humanos , Transdução de Sinais , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
BACKGROUND: To investigate the association between impairment of consciousness and risk of death in people with COVID-19. METHODS: In this multicentre retrospective study, we enrolled people with confirmed COVID-19 from 44 hospitals in Wuhan and Sichuan, China, between 18 January and 30 March 2020. We extracted demographics, clinical, laboratory data and consciousness level (as measured by the Glasgow Coma Scale (GCS) score) from medical records. We used Cox proportional hazards regression, structural equation modelling and survival time analysis to compare people with different progressions of impaired consciousness. RESULTS: We enrolled 1,143 people (average age 51.3 ± standard deviation 17.1-year-old; 50.3% males), of whom 76 died. Increased mortality risk was identified in people with GCS score between 9 and 14 (hazard ratio (HR) 46.76, p < .001) and below 9 (HR 65.86, p < .001). Pathway analysis suggested a significant direct association between consciousness level and death. Other factors, including age, oxygen saturation level and pH, had indirect associations with death mediated by GCS scores. People who developed impaired consciousness more rapidly either from symptoms onset (<10 days vs. 10-19 days, p = .025, <10 days vs. ≥20 days and 10-19 days vs. ≥20 days, <.001) or deterioration of oxygen saturation (≤2 days vs.>2 days, p = .028) had shorter survival times. CONCLUSION: Altered consciousness and its progression had a direct link with death in COVID-19. Interactions with age, oxygen saturation level and pH suggest possible pathophysiology. Further work to confirm these findings explore prevention strategies and interventions to decrease mortality is warranted.
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COVID-19/mortalidade , COVID-19/fisiopatologia , Estado de Consciência , Progressão da Doença , COVID-19/virologia , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2/patogenicidade , Fatores de TempoRESUMO
To enhance microalgal lipid production, canonical two-step cultivation strategy that by transferring the microalgal cells grown in nutrient-replete medium to nutrient-depleted medium is widely used. However, the harvesting step during the transfer raises the production cost. To avoid the harvesting step, this study developed a continuous two-step (CTS) cultivation strategy. In the strategy, Chlorella sacchrarophila was grown in bioreactor while a xylanolytic bacterium Cellvibrio pealriver grown in an inner bag that embedded in the bioreactor; after the first-step co-cultivation, the inner bag is removed which then start the second-step cultivation of C. sacchrarophila. Based on the strategy, the lipid production was determined as 825.34-929.79 mg·L-1, which were 1.7-1.9 times higher than that of cultivation in canonical two-step strategy using glucose as feedstock. During the CTS strategy, the co-cultivation using xylan as feedstock promotes the microalgal growth and the removal of inner bag produces nutrient-depleted condition for enhancing microalgal lipid production.
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Chlorella , Microalgas , Biocombustíveis , Biomassa , LipídeosRESUMO
Ammonia tolerance is a universal characteristic among the ammonia-oxidizing bacteria (AOB); in contrast, the known species of ammonia-oxidizing archaea (AOA) have been regarded as ammonia sensitive, until the identification of the genus "Candidatus Nitrosocosmicus." However, the mechanism of its ammonia tolerance has not been reported. In this study, the AOA species "Candidatus Nitrosocosmicus agrestis," obtained from agricultural soil, was determined to be able to tolerate high concentrations of NH3 (>1,500 µM). In the genome of this strain, which was recovered from metagenomic data, a full set of genes for the pathways of polysaccharide metabolism, urea hydrolysis, arginine synthesis, and polyamine synthesis was identified. Among them, the genes encoding cytoplasmic carbonic anhydrase (CA) and a potential polyamine transporter (drug/metabolite exporter [DME]) were found to be unique to the genus "Ca. Nitrosocosmicus." When "Ca. Nitrosocosmicus agrestis" was grown with high levels of ammonia, the genes that participate in CO2/HCO3 - conversion, glutamate/glutamine syntheses, arginine synthesis, polyamine synthesis, and polyamine excretion were significantly upregulated, and the polyamines, including putrescine and spermidine, had significant levels of production. Based on genome analysis, gene expression quantification, and polyamine determination, we propose that the production and excretion of polyamines is probably one of the reasons for the ammonia tolerance of "Ca. Nitrosocosmicus agrestis," and even of the genus "Ca. Nitrosocosmicus."IMPORTANCE Ammonia tolerance of AOA is usually much lower than that of the AOB, which makes the AOB rather than AOA a predominant ammonia oxidizer in agricultural soils, contributing to global N2O emission. Recently, some AOA species from the genus "Ca. Nitrosocosmicus" were also found to have high ammonia tolerance. However, the reported mechanism for the ammonia tolerance is very rare and indeterminate for AOB and for AOA species. In this study, an ammonia-tolerant AOA strain of the species "Ca. Nitrosocosmicus agrestis" was identified and its potential mechanisms for ammonia tolerance were explored. This study will be of benefit for determining more of the ecological role of AOA in agricultural soils or other environments.
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A novel sulfur-oxidizing bacterium, designated strain LSR1T, was enriched and isolated from a freshwater sediment sample collected from the Pearl River in Guangzhou, PR China. The strain was an obligate chemolithoautotroph, using thiosulfate or sulfide as an electron donor and energy source. Growth of strain LSR1T was observed at 15-40 °C, pH 6.0-7.5 and NaCl concentrations of 0-1.5â%. Strain LSR1T was microaerophilic, with growth only at oxygen content less than 10â%. Anaerobic growth was also observed when using nitrate as the sole electron acceptor. The major cellular fatty acids were C16â:â0 and summed feature 3 (comprising C16â:â1 ω7c and/or C16â:â1 ω6c). The DNA G+C content of the draft genome sequence was 67.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LSR1T formed a lineage within the family Thiobacillaceae, showing sequence identities of 92.87, 92.33 and 90.80â% with its closest relative genera Sulfuritortus, Annwoodia and Thiobacillus, respectively. The genome of strain LSR1T contained multiple genes encoding sulfur-oxidizing enzymes that catalyse thiosulfate and sulfide oxidation, and the gene encoding cbb 3-type cytochrome c oxidase and bd-type quinol oxidase, which enables strain LSR1T to perform sulphur oxidation under microaerophilic conditions. On the basis of phenotypic, genotypic and phylogenetic results, strain LSR1T is considered to represent a novel species of a new genus Parasulfuritortus within the family Thiobacillaceae, for which the name Parasulfuritortus cantonensis gen. nov., sp. nov. is proposed. The type strain is LSR1T (=GDMCC 1.1549=JCM 33645).
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Betaproteobacteria/classificação , Água Doce/microbiologia , Sedimentos Geológicos/microbiologia , Filogenia , Bactérias Redutoras de Enxofre/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Betaproteobacteria/isolamento & purificação , China , DNA Bacteriano/genética , Ácidos Graxos/química , Oxirredução , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Bactérias Redutoras de Enxofre/isolamento & purificaçãoRESUMO
We report the clinical characteristics, viral shedding duration, and contact tracing for asymptomatic carriers of SARS-CoV-2 in Wuhan, China. The asymptomatic carriers were relatively young (median age: 34.5 years). Chest computed tomography showed no abnormalities. The nasopharyngeal swab was an optimum specimen for RNA testing. The median viral shedding duration was 11.5 days. Notably, 2 months of viral shedding duration were reported in two nurses, which was much longer than previously reported or than usually thought. The transmissibility of SARS-CoV-2 by asymptomatic carriers during the studied period in Wuhan appeared to be weak. Only one patient (1/12) was found to have transmitted the virus to another person. Early asymptomatic carrier detection, isolation, and contact tracing could be useful to mitigate the spread of the disease.
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The COVID-19 outbreak is becoming a public health emergency. Data are limited on the clinical characteristics and causes of death. A retrospective analysis of COVID-19 deaths were performed for patients' clinical characteristics, laboratory results, and causes of death. In total, 56 patients (72.7%) of the decedents (male-female ratio 51:26, mean age 71 ± 13, mean survival time 17.4 ± 8.4 days) had comorbidities. Acute respiratory failure (ARF) and sepsis were the main causes of death. Increases in C-reactive protein (CRP), lactate dehydrogenase (LDH), D-dimer and lactic acid and decreases in lymphocytes were common laboratory results. Intergroup analysis showed that (1) most female decedents had cough and diabetes. (2) The proportion of young- and middle-aged deaths was higher than elderly deaths for males, while elderly decedents were more prone to myocardial injury and elevated CRP. (3) CRP and LDH increased and cluster of differentiation (CD) 4+ and CD8+ cells decreased significantly in patients with hypertension. The majority of COVID-19 decedents are male, especially elderly people with comorbidities. The main causes of death are ARF and sepsis. Most female decedents have cough and diabetes. Myocardial injury is common in elderly decedents. Patients with hypertension are prone to an increased inflammatory index, tissue hypoxia and cellular immune injury.
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Infecções por Coronavirus/mortalidade , Pneumonia Viral/mortalidade , Sepse/epidemiologia , Síndrome Respiratória Aguda Grave/epidemiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/análise , COVID-19 , Causas de Morte , China , Comorbidade , Infecções por Coronavirus/sangue , Infecções por Coronavirus/complicações , Infecções por Coronavirus/patologia , Diabetes Mellitus/epidemiologia , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Cardiopatias/epidemiologia , Humanos , L-Lactato Desidrogenase/sangue , Ácido Láctico/sangue , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/complicações , Pneumonia Viral/patologia , Sepse/etiologia , Síndrome Respiratória Aguda Grave/etiologiaRESUMO
Clinical data on coronavirus disease 2019 (COVID-19) with pancreatic injury are extremely limited. An acute manifestation of acute pancreatitis in COVID-19 has not been reported. We describe here 2 cases of COVID-19 with acute pancreatitis as the initial manifestation in Wuhan, China. Patient 1 died despite maximal mechanical ventilatory support and circulation support, while patient 2 was finally discharged after showing significant improvement. Low T cells in peripheral blood may indicate a poor outcome.
RESUMO
The coronavirus disease 2019 (COVID-19) outbreak has become a global health threat and will likely be one of the greatest global challenges in the near future. The battle between clinicians and the COVID-19 outbreak may be a "protracted war."The objective of this study was to investigate the risk factors for in-hospital mortality in patients with COVID-19, so as to provide a reference for the early diagnosis and treatment.This study retrospectively enrolled 118 patients diagnosed with COVID-19, who were admitted to Eastern District of Renmin Hospital of Wuhan University from February 04, 2020 to March 04, 2020. The demographics and laboratory data were collected and compared between survivors and nonsurvivors. The risk factors of in-hospital mortality were explored by univariable and multivariable logistic regression to construct a clinical prediction model, the prediction efficiency of which was verified by receiver-operating characteristic (ROC) curve.A total of 118 patients (49 males and 69 females) were included in this study; the results revealed that the following factors associated with in-hospital mortality: older age (odds ratio [OR] 1.175, 95% confidence interval [CI] 1.073-1.287, Pâ=â.001), neutrophil count greater than 6.3â×â10 cells/L (OR 7.174, (95% CI 2.295-22.432, Pâ=â.001), lymphocytopenia (OR 0.069, 95% CI 0.007-0.722, Pâ=â.026), prothrombin time >13 seconds (OR 11.869, 95% CI 1.433-98.278, Pâ=â.022), D-dimer >1âmg/L (OR 22.811, 95% CI 2.224-233.910, Pâ=â.008) and procalcitonin (PCT) >0.1 ng/mL (OR 23.022, 95% CI 3.108-170.532, Pâ=â.002). The area under the ROC curve (AUC) of the above indicators for predicting in-hospital mortality were 0.808 (95% CI 0.715-0.901), 0.809 (95% CI 0.710-0.907), 0.811 (95% CI 0.724-0.898), 0.745 (95% CI 0.643-0.847), 0.872 (95% CI 0.804-0.940), 0.881 (95% CI 0.809-0.953), respectively. The AUC of combined diagnosis of these aforementioned factors were 0.992 (95% CI 0.981-1.000).In conclusion, older age, increased neutrophil count, prothrombin time, D-dimer, PCT, and decreased lymphocyte count at admission were risk factors associated with in-hospital mortality of COVID-19. The prediction model combined of these factors could improve the early identification of mortality risk in COVID-19 patients.