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1.
Eye (Lond) ; 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382146

RESUMO

PURPOSE: To determine the expressions of SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2) genes in human and mouse ocular cells and comparison to other tissue cells. METHODS: Human conjunctiva and primary pterygium tissues were collected from pterygium patients who underwent surgery. The expression of ACE2 and TMPRSS2 genes was determined in human primary conjunctival and pterygium cells, human ocular and other tissue cell lines, mesenchymal stem cells as well as mouse ocular and other tissues by reverse transcription-polymerase chain reaction (RT-PCR) and SYBR green PCR. RESULTS: RT-PCR analysis showed consistent expression by 2 ACE2 gene primers in 2 out of 3 human conjunctival cells and pterygium cell lines. Expression by 2 TMPRSS2 gene primers could only be found in 1 out of 3 pterygium cell lines, but not in any conjunctival cells. Compared with the lung A549 cells, similar expression was noted in conjunctival and pterygium cells. In addition, mouse cornea had comparable expression of Tmprss2 gene and lower but prominent Ace2 gene expression compared with the lung tissue. CONCLUSION: Considering the necessity of both ACE2 and TMPRSS2 for SARS-CoV-2 infection, our results suggest that conjunctiva would be less likely to be infected by SARS-CoV-2, whereas pterygium possesses some possibility of SARS-CoV-2 infection. With high and consistent expression of Ace2 and Tmprss2 in cornea, cornea rather than conjunctiva has higher potential to be infected by SARS-CoV-2. Precaution is necessary to prevent possible SARS-CoV-2 infection through ocular surface in clinical practice.

2.
Genes (Basel) ; 11(5)2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32375366

RESUMO

Ancestry informative markers are genetic markers that show distinct genetic divergences among different populations. These markers can be utilized to discern population substructures and estimate the ancestral origins of unknown individuals. Previously, we developed a multiplex system of 30 ancestry informative single nucleotide polymorphism (AISNP) loci to facilitate ancestral inferences in different continental populations. In the current study, we first compared the ancestry resolutions of the 30 AISNPs and the other previously reported AISNP panels for African, European, East Asian, South Asian and American populations. Next, the genetic components of the Xinjiang Hui group were further explored in comparison to these continental populations based on the 30 AISNPs. Genetic divergence analyses of the 30 AISNPs in these five continental populations revealed that most of the AISNPs showed high genetic differentiations between these populations. Ancestry analysis comparisons of the 30 AISNPs and other published AISNPs revealed that these 30 AISNPs had comparable efficiency to other AISNP panels. Genetic relationship analyses among the studied Hui group and other continental populations demonstrated that the Hui group had close genetic affinities with East Asian populations and might share the genetic ancestries with East Asian populations. Overall, the 30 AISNPs can be used to predict the bio-geographical origins of different continental populations. Moreover, the obtained genetic data of 30 AISNPs in the Hui group can further enrich the extant reference data, which can be used as reference data for ancestry analyses of the Hui group.

3.
Plant J ; 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32365248

RESUMO

LIKE HETEROCHROMATIN PROTEIN1 (LHP1) encodes the only plant homologue of the metazoan HETEROCHROMATIN PROTEIN1 (HP1) protein family. LHP1 is necessary for proper epigenetic regulation of a range of developmental processes in plants. LHP1 is a transcriptional repressor of flowering related genes, such as FLOWERING LOCUS T (FT), FLOWERING LOCUS C (FLC), AGAMOUS (AG), and APETALA 3 (AP3). We found that LHP1 interacts with importin [alpha]-1 (IMPα-1), importin [alpha]-2 (IMPα-2), and importin [alpha]-3 (IMPα-3), both in vitro and in vivo. A genetic approach revealed that triple mutation of impα-1, impα-2, and impα-3 resulted in Arabidopsis plants with a rapid flowering phenotype similar to that of plants with mutations in lhp1 due to the up-regulation of FT expression. Nuclear targeting of LHP1 was severely impaired in the impα triple mutant, resulting in the de-repression of LHP1 target genes AG, AP3, and SHATTERPROOF 1 as well as FT. Therefore, the importin proteins IMPα-1, IMPα-2, and IMPα-3 are necessary for the nuclear import of LHP1.

4.
J Cell Mol Med ; 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32394619

RESUMO

Congenital scoliosis (CS) is a form of spinal curvature resulting from anomalous development of vertebrae. Recent studies demonstrated that circRNAs could serve as potential biomarkers of disease diagnosis. Genome-wide circRNAs expression in seven CS patients and three healthy controls was initially detected. Bioinformatics analysis was conducted to explore the potential pathological pathway of CS. Quantitative PCR (qPCR) was performed to validate the selected circRNAs in the replication cohort with 32 CS patients and 30 healthy controls. Logistic regression controlling for gender was conducted to compare the expression difference. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. Twenty-two differentially expressed circRNAs were filtered from genome-wide circRNA sequencing. Seven circRNAs were validated by qPCR. Only hsa_circ_0006719 was confirmed to have a higher expression level in the CS group than the healthy control group (P = 0.036). Receiver operating characteristic curve also suggested that hsa_circ_0006719 had significant diagnostic value for CS (AUC = 0.739, P = 0.001). We described the first study of circRNAs in CS and validated hsa_circ_0006719 as a potential novel diagnostic biomarker of CS.

5.
J Sci Food Agric ; 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32374035

RESUMO

BACKGROUND: Although rapeseed protein isolate (RPI) possessed some good functional properties, the use of RPI as an ingredient in the food industry is restricted mainly due to its inferior gelation. The purpose of this study was to improve the heat-induced gel properties of RPI using double processes of acylation and additional transglutaminase catalysis. RESULTS: Scanning electron microscopy showed that the gel formed by native RPI exhibited randomly aggregated particulate network structures whereas transglutaminase (TG)-assisted RPI gels significantly improved gelation properties. More importantly, the combined modifications of RPI using TG-assisted acylation can form a gel with unique percolating and small porous structure. Furthermore, TG-catalyzed 5% acylated RPI gel (100 U g-1 , protein basis) exhibited excellent gel properties in terms of gel strength, thermal stability, surface roughness and apparent viscosity compared to non-treated or single modification of RPI gel as determined by texture analyzer, atomic force microscopy and rheometer. Mechanistically, Fourier-transform infrared spectra and gel dissociation test revealed that TG-catalyzed acylation extensively unfolded the hydrophobic and sulfhydryl residues of RPI, in turn, reinforced re-assembly of protein molecules via hydrophobic interactions and disulfide bonds during gel formation. CONCLUSION: Combined processes of acylation and additional TG catalysis improved the thermal gelation properties by altering inter- and intra-protein structures. Such sequential processes will provide a promising approach to improve the protein gelation that could be potentially applied in the food industry. © 2020 Society of Chemical Industry.

6.
Eur J Radiol ; 128: 109017, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32387924

RESUMO

PURPOSE: To analyse the high-resolution computed tomography (HRCT) early imaging features and the changing trend of coronavirus disease 2019 (COVID-19) pneumonia. MATERIALS AND METHODS: Forty-six patients with COVID-19 pneumonia who had an isolated lesion on the first positive CT were enrolled in this study. The following parameters were recorded for each lesion: sites, sizes, location (peripheral or central), attenuation (ground-glass opacity or consolidation), and other abnormalities (supply pulmonary artery dilation, air bronchogram, interstitial thickening, etc.). The follow-up CT images were compared with the previous CT scans, and the development of the lesions was evaluated. RESULTS: The lesions tended to be peripheral and subpleural. All the lesions exhibited ground-glass opacity with or without consolidation. A higher proportion of supply pulmonary artery dilation (89.13 % [41/46]) and air bronchogram (69.57 % [32/46]) were found. Other findings included thickening of the intralobular interstitium and a halo sign of ground glass around a solid nodule. Cavitation, calcification or lymphadelopathy were not observed. The reticular patterns were noted from the 14 days after symptoms onset in 7 of 20 patients (45 %). At 22-31 days, the lesions were completely absorbed only in 2 of 7 patients (28.57 %). CONCLUSION: The typical early CT features of COVID-19 pneumonia are ground-glass opacity, and located peripheral or subpleural location, and with supply pulmonary artery dilation. Reticulation was evident after the 2nd week and persisted in half of patients evaluated in 4 weeks after the onset. Long-term follow-up is required to determine whether the reticulation represents irreversible fibrosis.

7.
Food Chem ; 326: 126976, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32413756

RESUMO

This study developed a novel electrochemical sensor containing nitrogen-doped ordered mesoporous carbon (NOMC) for the sensitive and selective quantification of l-tryptophan (Trp). The electro-oxidation mechanism of Trp on the NOMC/Nafion/glass carbon electrode (GCE) was first investigated, and was found to follow a two-electron/two-proton transfer mechanism. Subsequently, the analytical operation conditions were optimized. Under the optimum testing conditions, the oxidation current was found to increase linearly with Trp concentration in the ranges 0.5-70.0 µM and 70.0-200.0 µM (different slopes in each range), with the limit of detection determined to be 35.0 nM (S/N = 3). In addition, the sensor was highly selective for Trp and showed good repeatability and long-term stability. Studies of Trp in real world systems, such as an 18 amino acid mixture and an enzymatic protein hydrolysate, showed excellent recoveries (99.30-103.60%). Results suggest that NOMC/Nafion/GCE sensor has excellent performance characteristics for routine Trp analysis.

8.
J Agric Food Chem ; 68(17): 4844-4850, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32307989

RESUMO

Salicylic acid (SA), a crucial, plant-derived signal molecule, is capable of launching global transcriptional reprogramming to assist plants in obtaining the systemic acquired resistance (SAR) mechanism. Thus, the accurate detection of SA will not only significantly contribute to the understanding of the plant SAR but also contribute to crop protection and to the security of the agricultural production and food supply. However, detection of SA using fluorescent probes is a great challenge for scientists, because SA analogues can significantly interfere with the detection results. Herein, we first reported using a simple, natural curcumin-Cu2+ ensemble to selectively and sensitively monitor SA in situ and in vivo, directed by a fluorescence "turn-on" mode. A binary combination curcumin-Cu2+ was first fabricated with a fluorescence "turn-off" pattern caused by the paramagnetic nature of Cu2+. Subsequently, a fluorescence "turn-on" response was performed for detecting SA accompanied by the formation of the ternary complex curcumin-Cu2+-SA due to the high affinity of SA toward Cu2+, which reduced the fluorescent impact caused by the paramagnetism of Cu2+. Further study revealed that the rationally designed hybrid probe could monitor SA in living cell lines. We anticipate that this finding can inspire the discovery of a high-performance SA probe.

9.
Oncol Rep ; 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32319655

RESUMO

In a previous study, it was demonstrated that T­cell immune response cDNA 7 (TIRC7) levels reflect the efficacy of treatment of patients with acute graft­versus­host disease (GVHD). However, the pathogenesis of TIRC7 in acute GVHD remains poorly understood. Lymphocytes from patients with acute GVHD were selected as targeT cells, and the effects of TIRC7 on cytotoxic T lymphocyte antigen­4 (CTLA­4), T cell activation and cytokine secretion were observed by electroporation. A mouse model of acute GVHD was established; anti­TIRC7 and anti­CTLA­4 monoclonal antibodies were intraperitoneally injected into recipient mice. Then, the effects of TIRC7 and CTLA­4 on T cell activation and acute GVHD were monitored. After TIRC7 expression was downregulated, CTLA­4 levels were decreased and STAT3 phosphorylation was reduced; conversely, the activation capacity of T lymphocytes was elevated, and the secretion of interferon­Î³ and other cytokines was increased. The mice in the TIRC7 + CTLA­4 co­administration group exhibited the lowest acute GVHD scores, with the longest average survival time and shortest recovery time of hematopoietic reconstitution. In conclusion, the results indicated that TIRC7 may positively regulate the function of CTLA­4 and inhibit T cell activation, thus suppressing the development and progression of acute GVHD.

10.
Nat Med ; 26(5): 732-740, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32341578

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 editing of immune checkpoint genes could improve the efficacy of T cell therapy, but the first necessary undertaking is to understand the safety and feasibility. Here, we report results from a first-in-human phase I clinical trial of CRISPR-Cas9 PD-1-edited T cells in patients with advanced non-small-cell lung cancer (ClinicalTrials.gov NCT02793856). Primary endpoints were safety and feasibility, and the secondary endpoint was efficacy. The exploratory objectives included tracking of edited T cells. All prespecified endpoints were met. PD-1-edited T cells were manufactured ex vivo by cotransfection using electroporation of Cas9 and single guide RNA plasmids. A total of 22 patients were enrolled; 17 had sufficient edited T cells for infusion, and 12 were able to receive treatment. All treatment-related adverse events were grade 1/2. Edited T cells were detectable in peripheral blood after infusion. The median progression-free survival was 7.7 weeks (95% confidence interval, 6.9 to 8.5 weeks) and median overall survival was 42.6 weeks (95% confidence interval, 10.3-74.9 weeks). The median mutation frequency of off-target events was 0.05% (range, 0-0.25%) at 18 candidate sites by next generation sequencing. We conclude that clinical application of CRISPR-Cas9 gene-edited T cells is generally safe and feasible. Future trials should use superior gene editing approaches to improve therapeutic efficacy.

11.
Electrophoresis ; 2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32329071

RESUMO

Compound marker consists of two different types of genetic markers, like deletion/insertion polymorphism and single nucleotide polymorphism in the genomic region of 200 bp, and microhaplotype consists of a series of closely linked single nucleotide polymorphisms in a small DNA segment (<300 bp), which show great potential for human identifications and mixture analyses. In this study, we initially selected 23 novel genetic markers comprising 10 microhaplotypes and 13 compound markers according to previously reported single nucleotide polymorphism or deletion/insertion polymorphism loci. Genetic distributions of these 23 loci in different continental populations showed that they could be used as valuable loci for forensic human identification purpose. Besides, high informativeness values (>0.1) were observed in six loci which could be further employed for forensic ancestry analyses. Finally, 18 loci were successfully developed into a multiplex panel and detected by the next generation sequencing (NGS) technology. Further analyses of these 18 loci in the studied Shaanxi Han population showed that 15 loci exhibited relatively high expected heterozygosities (>0.5). Cumulative power of discrimination (0.999 999 999 99 4835) of these 18 loci revealed that the multiplex panel could also be utilized for human identifications in the studied Shaanxi Han population.

12.
Nat Commun ; 11(1): 1657, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32269225

RESUMO

The Scaly-foot Snail, Chrysomallon squamiferum, presents a combination of biomineralised features, reminiscent of enigmatic early fossil taxa with complex shells and sclerites such as sachtids, but in a recently-diverged living species which even has iron-infused hard parts. Thus the Scaly-foot Snail is an ideal model to study the genomic mechanisms underlying the evolutionary diversification of biomineralised armour. Here, we present a high-quality whole-genome assembly and tissue-specific transcriptomic data, and show that scale and shell formation in the Scaly-foot Snail employ independent subsets of 25 highly-expressed transcription factors. Comparisons with other lophotrochozoan genomes imply that this biomineralisation toolkit is ancient, though expression patterns differ across major lineages. We suggest that the ability of lophotrochozoan lineages to generate a wide range of hard parts, exemplified by the remarkable morphological disparity in Mollusca, draws on a capacity for dynamic modification of the expression and positioning of toolkit elements across the genome.

13.
Sensors (Basel) ; 20(7)2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32230996

RESUMO

Cancer has been one of the leading causes of death globally, with metastases and recurrences contributing to this result. The detection of circulating tumor cells (CTCs), which have been implicated as a major population of cells that is responsible for seeding and migration of tumor sites, could contribute to early detection of metastasis and recurrences, consequently increasing the chances of cure. This review article focuses on the current progress in microfluidics technology in CTCs diagnostics, extending to the use of nanomaterials and surface modification techniques for diagnostic applications, with an emphasis on the importance of integrating microchannels, nanomaterials, and surface modification techniques in the isolating and detecting of CTCs.

14.
Brain Res ; 1739: 146818, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32275911

RESUMO

Traumatic brain injury (TBI) is a major leading cause of death and long-term disability. Although astrocytes play a key role in neuroprotection after TBI in the early stage, the overactivation of astrocytes can lead to long-term functional deficits, and the underlying pathophysiological mechanisms remain unclear. In addition, it is unknown whether the nuclear factor erythroid 2-related factor2/haem oxygenase-1 (Nrf-2/HO-1) pathway could elicit a neuroprotective effect by decreasing astrocyte overactivation after TBI. We aimed to study the effects of tert-butylhydroquinone (TBHQ) in reducing astrocyte overactivation after TBI and explored the underlying mechanisms. We first established a controlled cortical impact (CCI) model in rats and performed Haematoxylin and eosin (H&E) staining to observe brain tissue damage. The cognitive function of rats was assessed by modified neurological severity scoring (mNSS) and Morris water maze (MWM) test. Astrocyte and microglia activation was detected by immunofluorescence staining. Oxidative stress conditions were investigated using Western blotting. An enzyme-linked immunosorbent assay (ELISA) was designed to assess the level of the proinflammatory factor tumour necrosis factor-alpha (TNF-α). Dihydroethidium (DHE) staining was used to detect reactive oxygen species (ROS). Apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The results showed that the administration of TBHQ ameliorated motor function and cognitive deficits and decreased the lesion volume. In addition, TBHQ significantly decreased astrocyte overactivation, diminished the pro-inflammatory phenotype M1 and inflammatory cytokines production after TBI, increased Nrf-2 nuclear accumulation, and enhanced the levels of the Nrf-2 downstream antioxidative genes HO-1 and NADPH-quinone oxidoreductase-1 (NQO-1). Furthermore, TBHQ treatment alleviated apoptosis and neuronal death in the cerebral cortex. Overall, our data indicated that the upregulation of Nrf-2 expression could enhance neuroprotection and decrease astrocyte overactivation and might represent a new theoretical basis for treating TBI.

15.
Food Chem ; 323: 126789, 2020 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-32315947

RESUMO

Soy protein isolate (SPI) and its derived hydrolysates (SPIHs) are popular food ingredients due to their demonstrated antioxidant, stabilizing and emulsifying properties. However, little is known about the interplays among these functions. This study aimed to fill this knowledge gap through comparing the antioxidant activities in single-phase assays systems and biphasic liposomal systems of the SPIHs produced by pepsin, trypsin or alcalase with/without flavourzyme. The peptide fraction of SPIHs with molecular weight < 1 kDa generally contributed more to the detected antioxidant activity. The combination hydrolysis of flavourzyme with pepsin/trypsin/alcalase significantly influenced SPIH's reducing power and Fe2+ chelating capacity. In liposomal systems, SPIHs influenced positively system's stability while inhibiting primary and secondary lipid oxidation products. Besides the factors affecting SPIH's antioxidant activity in the aqueous system (like amino acid composition, sequence and peptide chain length), interactions of peptides/amino acids with liposomal membrane and its lipid components also played critical roles.

16.
ACS Sens ; 5(5): 1314-1324, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32323526

RESUMO

The pyrophosphate ion (P2O74-, PPi) plays a critical role in various biological processes and acts as an essential indicator for physiological mechanism investigations and disease control monitoring. However, most of the currently available approaches for PPi species detection for practical usage still lack appropriate indicator generation, straightforward detection requirements, and operation convenience. In this study, a highly sensitive and selective PPi detection approach via the use of nanozymatic carbon dots (CDs) is introduced. This strategy eliminates the common need for metal ions in the detection process, where a direct indicator-PPi interaction is adopted to provide straightforward signal reports, and importantly, through a green indicator preparation. The preparation of this nanozymatic CDs' indicator utilizes an aqueous solution refluxing, employing galactose and histidine as the precursor materials. The mild conditions of the solution refluxing produce fluorescent CDs exhibiting peroxidase-mimic properties, which can catalyze the o-phenylenediamine oxidation under the presence of H2O2. The introduction of PPi species, interestingly, inhibits this process very efficiently, the extent of which can be colorimetrically monitored by the generated yellow product 2,3-diaminophenazine. Spectroscopic results point to CD surface functional groups' selective binding toward PPi species, which severely interferes with the electron transfer process in the enzymatic catalysis. Relying on this CD peroxidase-mimetic property inhibition, sensitive and selective recognition of PPi reaches a detection limit of 4.29 nM, enabling practical usage in complex matrixes. Owing to the superior compatibility and high stability of nanozymatic CDs, they can also be inkjet-printed on paper-based devices to create a portable and convenient platform for PPi detection. Both the solution and the paper-device-based selective recognitions confirm this unique and robust metal-free inhibitive PPi detection, which is supported by a convenient green preparation of nanozymatic CDs.

17.
J Exp Bot ; 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32189001

RESUMO

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), which consists of eight large subunits (RBCL) and eight small subunits (RBCS), is a major photosynthetic enzyme that is sensitive to chilling stress. However,it is largely unclear how plants maintain high Rubisco content under low temperature conditions. Here, we report that tomato WHIRLY1 (SlWHY1) positively regulates the Rubisco level under chilling stress by directly binding to the promoter region of SlRbcS1, resulting in the activation of SlRbcS1 expression. SlRbcS1 overexpressing lines had higher Rubisco contents and were more resistant to chilling stress compared with WT. qRT-PCR analyses showed that, among the five RbcS genes, only SlRbcS1 expression is up-regulated by chilling treatment. These results indicate that SlWHIRLY1 specifically enhances the levels of SlRbcS1 and confers tolerance to chilling stress. Amino acid sequence of SlRBCS1 shows 92.67% identity with those of other two RBCS proteins and four residues (R57, R105, and NS113) are specifically found in SlRBCS1. However, mutation of these residues to alanine in SlRBCS1 does not influence its function during cold adaptation. Thus, we conclude that high levels of Rubisco, but not the specific residues in SlRBCS1, play important roles in tolerance to chilling stress in tomato.

18.
Bioinformatics ; 36(10): 3156-3161, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32119079

RESUMO

MOTIVATION: Single cell RNA-sequencing (scRNA-seq) technology enables whole transcriptome profiling at single cell resolution and holds great promises in many biological and medical applications. Nevertheless, scRNA-seq often fails to capture expressed genes, leading to the prominent dropout problem. These dropouts cause many problems in down-stream analysis, such as significant increase of noises, power loss in differential expression analysis and obscuring of gene-to-gene or cell-to-cell relationship. Imputation of these dropout values can be beneficial in scRNA-seq data analysis. RESULTS: In this article, we model the dropout imputation problem as robust matrix decomposition. This model has minimal assumptions and allows us to develop a computational efficient imputation method called scRMD. Extensive data analysis shows that scRMD can accurately recover the dropout values and help to improve downstream analysis such as differential expression analysis and clustering analysis. AVAILABILITY AND IMPLEMENTATION: The R package scRMD is available at https://github.com/XiDsLab/scRMD. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

19.
Antimicrob Agents Chemother ; 64(5)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32122894

RESUMO

Tigecycline serves as one of the antibiotics of last resort to treat multidrug-resistant (including carbapenem-resistant) pathogens. However, the recently emerged plasmid-mediated tigecycline resistance mechanism, Tet(X), challenges the clinical efficacy of this class of antibiotics. In this study, we detected 180 tet(X)-harboring Acinetobacter isolates (8.9%, n = 180) from 2,018 samples collected from avian farms and adjacent environments in China. Eighteen tet(X)-harboring isolates (10.0%) were found to cocarry the carbapenemase gene bla NDM-1, mostly from waterfowl samples (94.4%, 17/18). Interestingly, among six Acinetobacter strains, tet(X) and bla NDM-1 were found to colocalize on the same plasmids. Moreover, whole-genome sequencing (WGS) revealed a novel orthologue of tet(X) in the six isolates coharboring tet(X) and bla NDM-1 Inverse PCR suggested that the two tet(X) genes form a single transposable unit and may be cotransferred. Sequence comparison between six tet(X)- and bla NDM-1-coharboring plasmids showed that they shared a highly homologous plasmid backbone even though they were isolated from different Acinetobacter species (three from Acinetobacter indicus, two from Acinetobacter schindleri, and one from Acinetobacter lwoffii) from various sources and from different geological regions, suggesting the horizontal genetic transfer of a common tet(X)- and bla NDM-1-coharboring plasmid among Acinetobacter species in China. Emergence and spread of such plasmids and strains are of great clinical concern, and measures must be implemented to avoid their dissemination.

20.
J Agric Food Chem ; 68(11): 3607-3614, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32091894

RESUMO

Recently plant protein Pickering particles have received tremendous interests because of their environmentally friendly, biodegradable, and safe characteristics. However, developing plant protein particles as stabilizers of Pickering emulsion still face many challenges. In current study, a novel nanogel system produced from acylated rapeseed protein isolates (ARPI) was used to stabilize Pickering emulsions. Results showed that self-assembled nanogel after native RPI modified by acylation adjusted the three-phase contact angle of ARPI nanogels system to 86.7° closing to a neutral wettability. At constant oil phase fraction (0.3, v/v), increasing the ARPI nanogels concentrations produced smaller droplet sizes of Pickering emulsions, whereas all freshly prepared Pickering emulsions were stable except 0.1% (w/v) ARPI nanogel-stabilized Pickering emulsion occurred with creaming. The rise of the oil phase fraction showed little influences on the droplets size and visual appearances of Pickering emulsions at a fixed ARPI nanogels concentration (0.75%, w/v). Moreover, the prepared ARPI nanogels stabilized Pickering emulsions were stable against aggregations of droplets at a range of pH conditions ranging from 5.5 to 8.5 and salt concentration as high as 0.2 M. Additionally, the ARPI nanogels concentration above 0.5% favored the formation of Pickering emulsion with long-term storage stability (up to 30 days) against creaming. Microscopic images evidenced that ARPI nanogels could absorb and anchor at the droplets surface forming an interfacial layer. Above findings may deliver a potential strategy for fabricating stable Pickering emulsion based on plant protein particles and are of important significance for the utilization of rapeseed protein in the food industry.

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